Which? Stove User Survey

Which? Stove User Survey

Which? has been championing the cause for consumers since 1957, asking probing questions of businesses and manufacturers, and pursuing the answers that put you in the driving seat.

A recent survey from Which? highlighted the importance of using professional services when it comes to purchasing and installing a wood burning stove. The survey which was sent directly to stove users provided some interesting insights for industry.

Consumer Survey

To find out how much people know about vital stove safety information, Which asked nearly 1,500 stove owners what details they were given when they bought their stove and had it installed.

One are of the survey focused on the stove purchasing process and identified the patchy level of information provided at the point of purchase.

Interestingly, our research also found that people who bought from a big-name retailer were less likely to have been given information than those who went directly to the brand or an independent store, installer or chimney sweep.

This was also the case for people who bought online, as opposed to buying in a physical store, especially when it came to the correct wattage for their stove or the best fuels. Just 43% of those who purchased online received this information compared with 71% of those who bought in a physical store.

HETAS firmly believes it is imperative consumers get expert advice and the right appliance for their home when considering buying a wood burning stove. HETAS Approved Retailers undertake training aimed towards providing consumers with the information they need to make the right choices when purchasing a stove. Stoves have become more sophisticated pieces of equipment, as manufacturers develop appliances with greater efficiency and substantially reduced emissions. HETAS continues to register a growing number of retailers.

Bruce Allen, CEO of HETAS, said: ‘It is imperative consumers get expert advice and the right appliance for their home when considering buying a wood burning stove.”

Allen also stressed the importance of making sure that stoves are installed and serviced by properly trained and registered professionals. Always check the ID card and registration of any trade professional you allow into your property.

In the last year, consumer calls to HETAS have doubled and many callers are asking what must be considered when choosing a stove. At HETAS, our Registered Installers and Approved Retailers advise customers how to operate their appliances effectively and safely.  Even consumers accustomed to solid fuel may need an update on the way that stoves best operate. Getting the right size stove is critical for comfort, efficiency and clean burning. HETAS has seen a growing number of retailers signing up the voluntary retailer scheme to demonstrate that their staff have undertaken the appropriate training.

User Habits

Consumers also admitted to Which? to some bad habits when it came to using their stoves. 14% of the stove owners we spoke to ‘slumber’ their stove – eg setting it to burn at a low output – most of the time, and 5% said they do this every time they use their stove. HETAS recently ran an article on the issues associated with slumbering a stove. The survey identified that more than a quarter of stove owners don’t know what the best fuel is for minimising pollution. A third weren’t told that the best fuel to use and nearly half (43%) weren’t told which ones to avoid – leaving them potentially using the most polluting fuels.

The government’s Clean Air Strategy, published earlier this year, included measures to ban the sale of the most polluting fuels and ensure only the cleanest wood stoves are sold. Industry eagerly awaits an announcement from government on the next steps for the Clean Air Strategy. In the meantime, check out our recent update on the strategy here.

HETAS continues to promote the importance using appropriately trained and registered professionals when it comes to using wood burning and multi-fuel stoves.

Ready for Inspection

Ready for inspection

When your HETAS inspector makes contact with you for your routine inspection, it is an opportunity to demonstrate your ongoing compliance with HETAS registration and compliance with Regulations. Here we highlight some tips to ensure a compliant inspection.

Prior to joining HETAS, installers must successfully complete training and are pass an onsite inspection of an installation. New registrants are required to be assessed annually for the first two years following their initial assessment to establish a clean track record. Existing registrants with a proven track record are assessed on a risk based method. This will involve a minimum of one on-site assessment of each existing registrant’s work every three years.

HETAS always wants to see installers pass their routine inspections first time round. It is important to understand that the inspector isn’t trying to catch you out, but is simply assessing your installation for compliance with the relevant Building Regulations, relevant Standards and manufacturer’s instructions.

The HETAS inspections team has created a useful checklist to help ensure you are ready for inspection on the day. Click here to download the checklist.

Some handy tips

For an inspection we do require the appliance to be unlit and cold. Some customers are keen to show off your installations in all it’s glory, which can make things that much harder for our inspectors.

It is vitally important to have the following documents to hand on inspection day:

  • A copy of your contract
  • Manufacturers instructions
  • Any design schematics (particularly for wet/heating systems)
  • Any factory insulated twin wall flue instructions/schematics or calculations
  • A commissioning certificate and HETAS certificate of compliance (or ID number if notified online)
  • Your HETAS Technical Handbook
  • Water Regulations Handbook (if relevant)
  • The relevant sections of Approved Documents applicable to the installation

Many of our inspections result in a flue draught reading being taken. We recently wrote about the importance of taking flue draught readings in our ‘Feeling the draught‘ article, along with the tools available to take a reading. Have your smoke pellets, draught gauage and a method to warm the flue available at the inspection.

Our inspectors have the equipment they need for inspections, but you should also bring along equipment that might help you through the inspection. Again, take a look at the checklist in advance of your inspection.

Common Faults to avoid

Your inspector will be checking for compliance with the above points and utilising the HETAS Unsafe Situations Procedure when identifying faults. Our results identify that more often than not, faults are of a low risk nature and can be easily rectified.

One of the more common issues that crops up on inspection fails is the positioning of carbon monoxide alarms. HETAS has clear guidance in Technical Note 22 (TN_0022). There are instances following an installation where consumers have removed the alarm. It is also useful to highlight to consumers the importance of the carbon monoxide alarm

Ensure you have photographic evidence in a portfolio evidencing your complaint installation work.

Click here to read Technical Note 22 guidance.

Additionally, notice plates can often disappear following the completion of an installation. As prescribed in Approved Document J, there are a number of requirements when it comes to notice plates.

The guidance which can be found on page 28 of Approved Document J states the following:

Notice Plates for hearths and flues (Requirement J5)

1.57 Where a hearth, fireplace (including aflue box), flue or chimney is provided or extended (including cases where a flue is provided as part of the refurbishment work), information essential to the correct application and use of these facilities should be permanently posted in the building. A way of meeting this requirement would be to provide a notice plate (as show in Diagram 16 conveying the following information:

a. the location of the hearth, fireplace (or flue box) or the location of the beginning of the flue;

b. the category of the flue and generic types of appliances that can be safely accommodated;

c. the type and size of the flue (or its liner if it has been relined) and the manufacturer’s name;

d. the installation date

1.59 Notice plates should be robust, indelibly marked and securely fixed in an unobtrusive but obvious position within the building such as:

a. next to the electricity consumer unit; or

b. next to the chimney or hearth described; or

c. next to the water supply stop-cock

Again remember to evidence the positioning of the notice plate when installing and ensure your customer is aware of it’s location.

HETAS branded notice plates can be ordered via the HETAS Shop.

The inspection comprises of a visual inspection, technical discussion and observation of testing/commissioning procedures.  Inspectors make it as informal as they can and will always try and make time to answer any questions you have during the process.

Inspections are a great way to speak to HETAS, as inspectors are in constant contact with main office.  If in doubt on any aspect of the HETAS insepction process, or if you have a technical question, please do not hesitate to contact the HETAS Technical Helpline. The helpline is a three strong team of time served industry experts who are there specifically to help our registrants.

Remember these top tips to ensure you breeze through your next routine inspection with HETAS.

Could an apprentice be right for your business?

Could an apprentice be right for your business?

With the cost of university fees at an all-time high, university is not always an option for school leavers. According to UCAS, average annual tuition fees for a student studying in England is now £9,250 per year. Paired with the additional costs of living, students could graduate with a substantial debt of £50,000 on average.[1]

A popular alternative to further education is apprenticeships. Open to anyone over the age of 16, an apprenticeship offers young people the opportunity to learn the practical skills of a job, along with the time to study. A variety of organisations across many industries now offer apprenticeships, including the BBC, McDonalds, Virgin Media, Marks & Spencer and Barclays.

Hiring an apprentice

To employ an apprentice you must have a genuine job vacancy to fill. The contract must last long enough for the apprentice to complete their apprenticeship, and must pay a wage. As of April 2018, the minimum hourly rate for apprentices under 18 years old is £4.20.

To advertise an apprenticeship you can post vacancies on your own website, or utilise the apprentice search function of the Government’s gov.uk website.

An apprentice doesn’t necessarily have to be a new employee, an apprenticeship could also be offered to an existing member of staff, so long as they meet the requirements.

Your responsibilities as an apprentice employer

As an employer you are required to select a training provider to support your apprentice throughout their contract. Apprentices must spend at least 20% of their time completing off-the-job training so you must take that into account. This could consist of workshops for example, shadowing a colleague or day release to college. These studies must be relevant to their apprenticeship.

The remainder of the apprentice’s time is spent on the job, learning and developing the skills required for their specific role. Within their work environment, apprentices must be supported by a mentor.

An apprenticeship must last a minimum of one year, and you are required to have an apprenticeship agreement in place with the apprentice, and a written agreement with the training provider for the duration.

Hiring an apprentice could be a good opportunity for your business to grow its talent with a skilled and qualified workforce. You could also be entitled to funding or additional payments from the Government so could be something to consider for your business.

It is a legal requirement to hold employers liability insurance of £10 million if you employ any staff, including apprentices. If you are considering hiring an apprentice and would like to discuss your insurance requirements, get in touch with the HETAS Insurance Services team on 01905 886 462, or email insurance@hetas.co.uk.

This is a marketing communication.

HETAS Limited is an Introducer Appointed Representative of Jelf insurance Brokers.

HETAS Insurance Services is a trading name of Jelf Insurance Brokers Ltd which is authorised and regulated by the Financial Conduct Authority (FCA). Not all products and services offered are regulated by the FCA.  Registered in England and Wales number 0837227. Registered Office: Hillside Court, Bowling Hill, Chipping Sodbury, BS37 6JX.

[1] BBC https://www.bbc.com/news/education-46607306

Source: www.gov.uk


Save on Which? Trusted Traders Membership

Save on Which? Trusted Traders membership

Which Trusted Traders74% of people are more likely to choose a business endorsed by Which?

Become a Which? Trusted Trader today.

HETAS members get 50% off the first 6 months!

We know your busy, so we’ll keep it short.

Which? Trusted Traders have teamed up with HETAS to bring members 50% off the first 6 months of becoming a Which? Endorsed trader.

HETAS is the stamp of approval in the solid fuel, biomass and chimneys world and Which? Is the stamp of approval in the consumer world; so it made sense for us to work together to help your customers recognise the best business!

Which? Is the UK’s #1 consumer champion, best known for our magazine subscriptions and independent product testing. The Which? icon is widely recognised by consumers and off the back of a recent survey, 74% of consumer are more likely to use a business because it’s endorsed by Which? – imagine the benefits this could have for your business.

The Which? Trusted Traders scheme was set up to recognise good honest tradespeople and help consumers to recognise who can be trusted. They don’t give the logo to anyone, your business needs to meet the assessment criteria in order to get on board. The assessment costs start from £200 + VAT for businesses with less than 19 employees and once you pass, you’ll get access to:

  • The Which? Trusted Traders logo to use on customer facing material
  • A profile on the Which? Trusted Trader website
  • 100% Moderated reviews
  • A live feed of your reviews for your website
  • An alternative dispute resolution service
  • A dedicated account manager
  • Subscription to the Which? Magazine

To find out more and to get assessed, contact us on 0117 456 6036 9am – 5pm Monday to Friday and quote PA-Leaf or request a call back online here via our website.

 * Cint panel research survey of 1,034 members of the general public (30 September to 2 October 2018)


HETAS Guide 2019

HETAS Guide 2019 published

HETAS Guide 2019HETAS is proud to announce the publication of the HETAS Guide 2019. You should already have received your copy of the new Guide. More than ever before consumers want the right advice before purchasing an appliance, the HETAS Guide can help.

A vital tool for HETAS installers and retailers, the new HETAS Guide 2019 is packed to the brim with clear, concise information on approved appliances and equipment, yet retains a similar look and feel following positive feedback from installers, retailers and manufacturers. The Guide’s principal aim remains, to assist consumers making sure they get expert advice and the right appliance for their home.

An important publication

Bruce Allen, HETAS CEO said:

“More than ever before, consumers are feeling the need to speak to someone before they choose and appliance. With awareness of Defra’s Clean Air Strategy and the benefits of carbon saving from wood fuel, the purchasing decision can seem relatively complex. In the last year consumer calls to HETAS have doubled and many calls are about what must be considered when choosing a stove. At that point we can use the information we have on the website and in the HETAS Guide 2019 to help people choose an appliance that suits the location, is the right size and has the attributes that fit their lifestyle – we can pass customers on to retailers, manufacturers, registered installers. This year we have had record numbers of visitors to our website.”

Within the Guide, HETAS can verify that appliances have been tested and CE marked and that the instructions are adequate and in English; also, that installation guidance and appliance data ensures that competent installers can install an appliance in a way that meets UK Building Regulations.

Bruce added:

“A key benefit of the HETAS third party independent product scheme is that customers can see that any listed stove, chimney, boiler or ancillary product has a third-party independent and impartial validation. Customers like the comfort they get from third party assessment.”

The HETAS Guide 2019 also includes a full list of Woodsure and Ready to Burn suppliers accredited on the UK’s only woodfuel quality assurance scheme.

For 2019, the Guide was also sent out in biodegradable packaging to reduce on the use of plastic.

Get in touch with the HETAS team to request your copy of the HETAS Guide.

Further Reading


Be Alarmed

Be alarmed

CO Positioning TN 0022The positioning of a carbon monoxide alarms can be an important factor in ensuring compliance with Approved Document J and ensuring an alarm has the best opportunity to identify carbon monoxide. HETAS Technical Note 0022 has all the information you need.

Questions from installers over the type, suitability and positioning of carbon monoxide alarms continue to be a regular occurrence on the HETAS technical helpline. There is confusion caused by differing guidance and advice on suitable positioning given within UK Building Regulation approved documents and CO alarm manufacturer installation instructions. When installed, operated and maintained correctly, instances of solid fuel appliance CO spillage are rare, nonetheless the Building Regulations still require all new or replacement solid fuel appliance installations to permanently affix a CO alarm in the room in which the appliance is located. Improper selection and location of an alarm may result in CO detection being limited, leading to an increase in the time taken for CO activation upon spillage occurring and decrease in time available for occupants to vacate the building safely.

What do the Building Regulations Say?

Approved Document J of the Building Regulations lays out the statutory requirements for installations of solid fuel appliances. In particular regulation J3 states the following:

Warning of Release of Carbon Monoxide

J3. Where a fixed combustion appliance is provided, appropriate provision shall be made to detect and give warning of the release of carbon monoxide.

 The regulations are clear in laying out the conditions for ensuring a CO alarm compliant with BS EN 50291 is present upon installation of a solid fuel appliance, however establishing the suitable type, position and fixing method is where confusion can exist between current appropriate standards and alarm manufacturers’ installation instructions.

Supplementary Information on Selection & Positioning

As well as the statutory requirements detailed on page9 of ADJ, further information can be found within:

  • Clause 2.34 to 2.36 of Approved Document J
  • Supplementary product and installation standards including BS EN 50292 & BS 8303
  • Alarm Manufacturer Instructions

Although the regulations simply require appropriate provision to be made, it is important for the general safety of the occupants that installers and landlords are selecting and positioning an alarm effectively allowing the quickest response time from the alarm for the occupants to vacate the premises. This document details some of the best practice considerations and should be followed as closely as possible It is worth noting that manufacturers who supply alarms do so for a number of different technology types, so guidance provided may cover suitable provisions for a range of appliances.

Best Practice

Confusion around the appropriate selection and positioning of a CO alarm normally comes about where the installer or landlord are being provided conflicting advice from a variety of sources. It is important for the installer or landlord to understand the behaviour of CO emissions to assess in practice the best location of the alarm. In principle, CO has almost the same density as air and would be emitted as part of spillage of combustion products which are hot and will warm the air around the appliance. This warmer air is likely to rise due to its buoyant characteristics, which supports best practice measures and those given within regulatory guideline in positioning the CO alarm at a high position on the wall or on the ceiling.

Whilst complying with J3 of the Building Regulations, it is important to ensure the CO alarm is of a suitable type and positioned in a suitable location as to provide the best warning of CO upon spillage. The referenced provisions below allow for the installer/landlord to competently enforce best practice on the selection and positioning within a room containing a solid fuel appliance.

Product Selection – Alarm Type

A suitable alarm will have been tested to confirm it meets the necessary requirements of BS EN 50291:2010, and activate within the required time when the relevant volume of CO is detected. The alarm packaging itself will contain the relevant information, including appropriate Kitemark reference (if tested by BSI) and also confirmation of the test method standard, warning of the expected lifetime of the sensor and where incorporated stating the product includes an end of life indication.

Sealed for life vs Replaceable

There are currently three known types of alarm on the market, which are:

  • Sealed for Life: Alarms that have a fixed, sealed power source which will require complete replacement once the end of life which is normally a minimum of 5 years
  • Replaceable battery: Alarms that have a replaceable power source
  • Mains powered: Alarms normally powered by wired mains electricity but containing a back-up battery for mains failure events

It is important to note that any of these three types of CO alarm are suitable for use with solid fuel installations. If they have been confirmed as meeting the requirements of BS EN 50291 then they shall incorporate a warning device to alert users when the working life of the alarm is coming to an end. It is important for any installer landlord to ensure that they educate the consumer in knowing what action to take when the alarm sounds, and that the end-of- life warning means the unit or battery will need to be replaced and new alarm tested immediately. Landlords and installers can further educate the consumer or tenant by ensuring a test of the operation of the alarm is undertaken on a regular basis.

All manufacturer’s alarms compliant with BS EN 50291 will contain a “test button” which when pressed will sound an audible alarm and flash its LEDs to show that the alarm is correctly operating.

Alarm Positioning

The general provisions within ADJ and BS8303 ask that the CO alarm be positioned in a location which provides means for the immediate detection of CO upon spillage from a solid fuel appliance. Guidance in ADJ and in BS8303 is that CO alarms should be positioned as follows;

  1. a) On the ceiling at least 300mm from any wall or, if it is located on a wall as high up as possible (above any doors or windows) but not within 150mm of the celling; and
  1. b) Between 1m and 3m horizontally from the appliance

These stated parameters allow for the earliest possible detection of CO as the combustion products disperse and mix with the air within the room. In these positions the detector is also avoiding the relevant “dead zone” areas whereby the velocity of gases disperse and convect in a circular motion and do not reach the corner areas of the room. It is also important to ensure CO alarms are not located directly next to the appliance, or within areas where air disperses at a slower rate. Typically installations of solid fuel appliances are within a builder’s recess, where the flue is contained within a masonry chimney stack which protrudes slightly into the room in which the appliance is installed. Following best practice, it is also recommended for CO alarms not to be located on the side wall of the masonry stack, which again acts as a potential “dead zone”, which may increase the activation response time of the alarm as the CO disperses into the room in a radiant motion.

Be Alarmed | Carbon monoxide guidance from HETAS

Landlord Requirements

Since the 1st October 2015, regulations now require landlords in England to ensure a co alarm is fitted in any room containing a solid fuel appliance within rented residential accommodation. This applies to both new and existing installations and failure to follow the new legislation can lead to a civil penalty being imposed on the landlord, whose responsibility it is to ensure compliance. Regulations in Scotland and Northern Ireland require similar CO alarm provision. Landlords will be required to check the condition and operation of the alarm at the beginning of each tenancy, however the regulations do not provide information of the placement of alarms, only that the landlord follows the provided guidance within Building Regulations, standards and CO alarm manufacturer’s instructions.

Affixing the Alarm

The regulations currently state that “appropriate provision shall be made to detect and give warning of the release of CO”. Having checked with the Government department responsible, we can state that “appropriate provision” is seen as permanently affixing a suitable alarm to the wall/ceiling in an appropriate place, and that simply leaving an alarm with a customer is not seen as “appropriate provision”. It is vital for the installer to educate the consumer in the importance of the alarm, its position and what to do when the alarm sounds. This document can be used as evidence of the things to be considered and the reasoning behind the requirements. This important information can be relayed to the consumer as part of the commission and handover process.

Further Information

HETAS currently work closely with the Council of Gas Detection and Environmental Monitoring (CoGDEM) in ensuring continued safety in the operation and use of all solid fuel burning appliances. Further information and support on CO alarm requirements can be obtained from the HETAS Technical Helpline on 01684 278194 or by contacting the CoGDEM CO helpline on 0800 1694 457.


Fireplace surround Update

Surround Update

In recent years HETAS has been made aware of a small number of fatalities caused by incorrectly fitted fireplace surrounds. In a recent court case, a “cowboy job” was said to be the cause of the death of two-year-old boy.

Bram Radcliffe was in his living room when the 60kg fixture, described as “an accident waiting to happen”, fell.  Bradford Coroner’s Court heard mum Amy Johnson heard a loud bang and rushed in to find the “lifeless” toddler. Recording a narrative verdict, Martin Fleming described the installation as “sub-standard and dangerous”.

The inquest heard the coal fire was decorated with a marble surround, which was glued and screwed into plasterboard. Coroner Mr Fleming said: “I can only suggest that it was installed either by a cowboy or a cowboy firm, or a DIY enthusiast.”

Whilst any death or injury is unacceptable, what makes this situation worse is that the deaths have happened to the most vulnerable in our society: young children. Toddlers learning to walk often use furniture to pull themselves up onto their feet. A young child pulling on an insecurely fixed fireplace surround can easily load the mantel beyond the point of stability and cause it to topple onto themselves.

Bonding the surround’s back to the wall isn’t considered a suitable method of fixing as bonds can break or be weakened by the thermal movement between the chimney breast and surround. Correct mechanical fixing is the only safe option, with the surround being fixed in place using brackets that are designed to take both the dead load of the surround components and any imposed load from objects placed on the mantel, and children or adults pulling up on it.

Manufacturer Guidance

Manufacturers have been instructed by HSE to take the necessary measures to ensure the surrounds are securely ­fixed, giving the following guidance for the information that should be provided to the installer of the surround:

  • Which wall/floor types the fireplace surround may be suitable for and those on which it should not be mounted (e.g. non-structural walls such as demountable partitions or lightweight metal stud walls, etc).
  • How the surround is to be assembled including the correct sequence.
  • The recommended bonding products and the extent of their application (e.g. area and joint thickness) to bed the individual stone components together, and the recommended method of using the bonding product – given the type of stone involved (e.g. pre-wet porous or impervious).
  • How the fireplace surround should be secured to different forms of wall construction and finish.
  • The number and type of mechanical fittings to be used, where they are positioned, and how they are to be fixed to both the stone components and to the wall to hold and secure the stones in position.
  • The curing time before the fireplace can be used with a lit fire or appliance.
  • Any additional information for the home-owner e.g. how much weight may be placed upon the mantel.

To help strengthen the requirements for fixing fireplace surrounds BS 1251:2015 Speci­fication for open-­ replace components was redrafted to include extra guidance on fixing both cast stone and cut stone fire surrounds.

Further Reading

For more information visit the HSE bulletin Risks to occupiers from the installation of modular, stone and arti­ficial stone ­ replace surrounds.


Download the Stone Federation of Great Britain’s guidance on fixing fireplace surrounds which was published in 2013 and revised in 2015:


Alternatively contact the HETAS Technical Helpline for advice on 01684 278194 or email technical@hetas.co.uk.

You can access HETAS Technical Bulletin #1 and all of our other bulletins in the HETAS Technical Area (login details required).


Slumbering your stove

Slumbering your stove

Back in 2014 HETAS ran an article on slumbering in Technical Bulletin #4. Slumbering can cause issues if an appliance isn’t designed to do so. With air quality a headline issue, HETAS is issuing a reminder to registrants.

Slumber mode is when an appliance is purposely set at a low or minimum  output normally for overnight burning to be revived in the morning without the need for relighting. Some mineral fuel burning appliances are designed to operate in a slumbering mode and would be CE type tested to show that they are safe to operate in this manner. A small number of wood burners have been CE type tested for continuous operation and have been shown to be safe and able to slumber for the required 10 hours minimum and be revived again at the end.

User Beware

Users should however be aware that there are particular problems associated with using an appliance for extended periods at low output especially if the appliance is not designed to operate in this way. Similarly, these problems occur if the appliance has not been sized according to the heating load applied to it so that it must be turned down to low output in order for the living space to be comfortable.

Problems with slumbering

Running appliances at low output can lead to incomplete combustion, especially when burning a high volatile content fuel such as wood logs. This will lead to the formation of sooty and/or try deposits on the flue lining as well as increased levels of carbon monoxide and particulates in the products of combustion. In addition,  when appliances are used at low output for extended periods of time the temperature of the chimney reduces and there is a tendency for the products of combustion to also be lower in temperature – which will lead to an increased likelihood of condensation forming in the chimney.

The presence of condensation together with flue deposits that may contain acidic compounds will present a risk of corrosion where metallic components are used for the flue lining. If the intended use of the appliance is for slumbering on a regular basis then it is wise, whenever it is necessary to reline the chimney, to choose a lining system that does not have metallic components. See ‘flexible liners’ below.

Even when an appliance is designed for slumbering it is necessary to adopt certain practices in order to reduce the negative effects of operating at low outputs. Usually this involves running the appliance at high output following slumbering to hopefully burn away any flue deposits and to ensure the chimney warms up sufficiently to provide a good draught and reduce the risk of condensation. Never overload an appliance.

Flexible Liners

Flexible liners, whilst being easier to install and replace, are not designed to last the life of the building, but may (when using the appliance correctly) last in excess of 10 years. Long periods of slumbering and/or infrequent chimney sweeping can cause corrosion damage which has been known to reduce the expected life of a flexible metal flue liner to less than five years.

The efficiency and life expectancy of any chimney is dependent upon correct use and maintenance. Masonry and pre-cast chimney products – whilst usually offering long life and high resistance to risk of corrosion – tend to involve more installation work when compared with metallic chimney systems.

Metal liners and insulated metal chimneys offer fast and convenient installation. However, they can be less resistant to damage by corrosion, particularly if subjected to abuse or inadequate cleaning. Allowing soot or condensate deposits to accumulate in metal lined chimneys and also prolonged periods of burning in slumbering conditions, particularly on closed appliances, can cause high concentrations of corrosive condensates to build up and attack the metal liner. This situation can not only considerably reduce the life of the flue lining, but can also invalidate the manufacturer’s warranty.

Carbon Monoxide, particulates and slumbering

It is important not to allow the appliance to repeatedly remain in slumber mode for long periods; this practice ultimately starves the appliance of air giving rise to an increase of carbon monoxide and particulates. Leigh Greenham of CoGDEM advises that many of the calls he gets on the COGDEM helpline surround consumers slumbering an appliance and leaving the door open to get extra heat into the room, increasing further the risk of CO.

Users aren’t always aware of the dangers of doing this. If they don’t want to put another log on the stove at the end of the evening, they often open the doors in an effort to extract the last bit of heat from the stove. However, the heat-recovery design of the stove normally causes the products of combustion to take a tortuous route around the stove to the flue, but when the stove cools there is not enough energy to drive the products in this way.

So the embers, which are still producing quantities of CO, have insufficient heat energy to drive the products to the flue in the normal way, so the products take the easier route and spill into the room through the open door. Fortunately, the cases we get to hear about are those where a nearby CO alarm has reacted appropriately.

Appliance Output

It is imperative that the output of the appliance is considered when planning any stove installation; should the appliance be oversized then this may give rise to the end user operating the appliance with the controls turned down, effectively slumbering the stove. In contrast an appliance with an output too small for the room it is being used in will lead to inadequate heat output. The HETAS Guide gives appropriate guidance on appliance sizing.

Further Reading



Daniel Park Sentencing

Daniel Park Sentencing

Another rogue installer has been brought to justice following an investigation by Trading Standards, supported by HETAS. Daniel Park was given a suspended jail sentence and ordered to carry out 200 hours of unpaid work.


Back in December we issued an update on a number of Trading Standards success stories, with HETAS providing a supporting role in ensuring enforcement action. One case was Daniel Park, a Crewkerne trader was accused of false and misleading practices towards his customers. While trading as ‘Flaming Burners’ in March 2017 Mr Park admitted to dishonestly making a false representation on his business’s Facebook page that he was registered with HETAS and a number of other schemes.

Park was sentenced to an 18-month conditional discharge and fined £400. He was also ordered to pay £800 towards the County Council’s prosecution costs. An additional £302 compensation was awarded to the victims.

Park was due to appear before Somerset Magistrates to enter pleas to 12 separate allegations but did not show up. A warrant was issued for his arrest.

Court Appearance

26-year-old Daniel Park from Crewkerne was prosecuted by Dorset County Council and pleaded guilty at Weymouth Magistrates’ Court on 5 November 2018 to three offences of publishing misleading claims: one under the Fraud Act 2006 and two under the Consumer Protection from Unfair Trading Regulations 2008.
While trading as ‘Flaming Burners’ in March 2017 Mr Park admitted to dishonestly making a false representation on his business’s Facebook page that he was registered with HETAS (Heating Equipment Testing Approvals Scheme) and other organisations.

HETAS has been supporting consumers who have been misled by Park and along with one consumer, HETAS featured on BBC Points West to identify the poor workmanship undetaken by Park and promoting the benefits of using a HETAS Registered Installer.


Representing himself, he told Recorder Jonathan Barnes he was “very sorry” for what he had done, adding that he had “found himself in a position where he didn’t know what he was doing”.

Sentencing him, Mr Barnes said:

“You operated as a rogue trader causing some customers substantial financial loss. You held yourself up as a competent qualified and appropriately-registered installer of wood burners and solid fuel stoves. You had a Facebook site where you obtained work but it was full of fraudulent and misleading information about your qualifications.”

He also stated “There can be no question of you working as a rogue trader again. If you do you will go straight to prison and to prison for a long time.”


Park has been given a four-month jail sentence suspended for two years and was also ordered to carry out 200 hours of unpaid work.

HETAS received thanks from the Trading Standards for our time in providing evidence for this case, without which Park would likely not have been prosecuted.

HETAS will continue to work hard to promote reputable registered installers and tackle rogue installers with support from Trading Stnadards. If you are aware of a rogue installer or someone falsely claiming to be registered with HETAS please contact our whistleblowing team. Used to ensure consumer safety and prevent bad installations, the whistleblowing helpline is a great resource for those seeking both action and solutions.

A HETAS representative says: “We always want to hear about businesses falsely claiming to be HETAS registered, who appear to be misusing the brand or those who do not comply with standards and regulations. As an organisation, our purpose is to promote the safe and effective use of solid fuels, biomass and related technologies. We would implore anyone with any concerns about rogue traders in your area or non-compliant installations to get in touch with HETAS.”

Contact the team

Get in touch on info@hetas.co.uk or contact the team directly on 01684 278170.


Feeling the Draught

Feeling the Draught

Commissioning of an appliance is a vital part of the installation process and a draught gauge is a really important item to hold in your tool kit to ensure the job is done properly. Here are some top tips on getting it right.

Flue Draught Test

The constant flow of flue gases at the correct rate of flow with the least possible variation is required for safe and efficient combustion. Insufficient flue draught will cause ignition difficulties and is likely to result in fume emission and a potential health risk. Too much draught will make control of the fire difficult and may result in overheating.  In this instance, fitting a draught stabiliser may be required. An appliance manufacturer will specify a range of flue draft conditions under which their appliance will operate.

Flue draught readings can be taken using a purpose made flue draught gauge or using any suitable pressure differential measurement device. See our examples later on in the article.

The correct place for measuring the chimney draught is close to the appliance and at least 150mm away from any draught regulator. Sometimes this distance may also be described as two times flue diameter.

Some appliances include purpose-made flue draught test points for test equipment sampling probe insertion. If no purpose-made point exists, a suitable point will need to be provided adjacent to the appliance outlet. In some instances a draught measurement can be taken by temporarily removing a sweeping access cover and using a cone or plate with a hole in the centre to prevent secondary air entry and enable insertion of the sampling probe. A flue draught reading should be taken before the appliance is lit to identify potential problems which could result from down draught.

Procedure for Taking Flue Draught Readings

The typical procedure when using a purpose made mechanical draught gauge as shown in Fig 30 is as follows:

1.   Visually inspect the draught gauge for signs of damage and/or defect.

2.  Ignite a small amount of fuel in the appliance and leave to burn for 20 minutes.

3.   Adjust pointer to zero (before each measurement).

4.  Position the gauge on a level base or hang upright.

5.   Insert metal sampling tube into test point preventing secondary air entry.

6.  Wait approximately 30 seconds for stabilisation and then take the draught reading.

7.     Take the reading every 10 minutes until the maximum draught is reached

Please Note: Atmospheric or weather conditions may cause incorrect draught readings.


Depending upon the draught reading obtained, it may be necessary to adjust the appliance air control devices and/or the flue draught stabiliser (if fitted). Any adjustment should be made in accordance with the appliance manufacturer’s instructions and the draught should be reading retaken after each adjustment.

If acceptable draught conditions are not able to be achieved, the appliance should be taken out of service and where appropriate the HETAS unsafe situations procedure (see HUSP form below) should be followed while the fault is rectified. Refer to Appendix E in the back of this Unit for more details.

Testing & Commissioning

Unless you have to leave a warning notice, a summary successful maintenance report for your customer will add a level of professionalism and give reassurance that you are leaving the installation in a safe state. A signed and dated testing & Commissioning sheet should offer the following as relevant:

·         Confirm operation status as per manufacturers requirements.

·         Confirm or detail non-compliance with current requirements.

·         Check the CO Alarm is operational and correctly positioned.

·         To check/confirm the condition of the “hidden seals” within the appliance carry out Smoke Test I.


·         Smoke Draw Test (Smoke Test II). This should be carried out with all the doors and windows closed in the room in which the appliance is installed.

·         Confirm flue draft readings are as per manufacturers requirements.

·         Ensure end user is confident in the continued use of the appliance.

·         Complete appropriate paperwork and where necessary obtaining customer signature and leave a copy with the customer.

Draught Gauges

HETAS currently has three draught gauges available in the HETAS Shop.


HETAS have produced the Unsafe Situation Procedure Assessment Form to help installers assess whether an installation is to be deemed unsafe and lists the re-commisioning checks needed if the installation is found to be compliant.

Visit the HETAS Technical Area for further information on the HUSP.