Given the mystifying absence of the promised BS 7967 relating to use of Flue Gas Analysers, we decided it was time to publish an update on the topic of Flue Gas Analysis, collating all information known to us.

Helpfully the Managing Director of British Gas (Mark Clare) sent a letter to the Sunday Telegraph (January 19 2003 – Page 28) and that letter provides a useful platform from which to launch our Comment. We recommend you read the letter first.

There have apparently been some unpopular allegations voiced at the Sunday Telegraph in re British Gas. We have not been concerned with those matters. Our main focus has to be the last paragraph in Mark Clare’s letter. We would not wish to dispute the alleged halving (yes 50%) of breakdowns but we do categorically dispute the absurd suggestion that use of Flue Gas Analysis had any role whatsoever to play in reducing breakdown figures; It is not possible.

What is wrong with Flue Gas Analysers ? As far as we are aware, nothing at all. The relevant British Standard for FGA is BS 7927: 1998 which permits self certification by manufacturers. One manufacturer at least has obtained independent compliance certification. Providing the apparatus is annually calibrated and certified (not cheap) it remains legal. We invested in the Telegan Tempest 50 with everything on and have taken hundreds of readings. We therefore have substantial experience to call upon.

In this domestic gas context we’ll kick the debate off by confirming that FGA does not actually exist Officially we mean. Enter, the Council for Registered Gas Installers (CORGI) who are the currently approved (by the HSE) industry watchdog.

When Corgi give advice to Installers on any topic they always point to relevant standards in support, known as normative documents. There is no such document relating to Flue Gas Analysis in this context. You may of course ask them if you wish but we would only be interested in commenting on any written answer from Corgi.

The official Corgi magazine the Gas Installer (TGI) in April 2001 permitted the publication of an unsafe article by Peter Turner, Director of Telegan Gas Monitoring. The first paragraph of that article stated “THE proposed British Standard 7967 for flue gas analysers, which will lay down standards on how to use the devices, is now out in draft form and heading towards being finalised.”

Gas-News contacted BSI-Global recently only to be informed, after an exhaustive search that BS 7967 does not exist. There is no draft BS 7967 either “heading towards being finalised”. And there never has been ? Interrogation of the BSI-Global.com website confirms this information. Without that British Standard, FGA remains a vision.

Nothing to stop anyone, including us and the good folk at the cutting edge of British Gas from using FGA. Perfectly safe to use as an enhancement of existing good trade practice. British Gas are subject to precisely the same regulations and regime as any other Registered Gas Installer. There are no exceptions. In the eyes of the Gas Safety (Installation and Use) Regulations (GSIUR) we are all equal. We will never allow that some are more equal than others.

Our concern with that article was another paragraph “When you perform an annual service on a boiler, the flue gas analyser tells you if the boiler is working efficiently, and if it is, there is no point in stripping it down” – That statement was reckless, wholly untrue and Corgi should not have permitted publication.

But they did ?

There is a well understood and overriding maxim in the industry. That is to say Manufacturer’s Instructions. Any advice offered in support of a gas appliance is always embellished with the words ‘see manufacturer’s instructions’. With that in mind we would point out that an annual service on a gas appliance must take the course specified in by Manufacturer’s Instructions. FGA would only be relevant if it is mentioned by Manufacturer’s Instructions.

Talking of Manufacturer’s Instructions, Peter Turner would do well to stick to FGA and not subvert the good advice offered by boiler manufacturers. Which reminds me. The April 2001 article also states “we are not in a position to advise heating engineers on how to use them (Ed-FGA)”. Very helpful to a new industry entrant or FGA novice. Currently, no one can offer advice on how to use them. And I mean no one.

There’s more yet. The Corgi Chief Technical Officer in April 2001 tried to defend the article with spurious argument, when we complained to Corgi and the HSE. He has now moved to a new post as Head of Technical and Safety at the HVCA. In that new role he participates in an HSE Working Group serving under the current Gas Safety Review. Now he is singing from a different hymn sheet, representing industry, his publicised comment (Note 1) to the HSE on the role of FGA recently was “much more work will be needed before the use of FGA’s can even be recognised as an additional good practice tool”.

Are we all sufficiently confused ? This falls into the category first described by one of our valued visitors as a ‘classic Corgi contradiction’. Unfortunately that is not all.

There is a scheme called the Accredited Certification Scheme for Individual Gas Fitting Operatives. Affectionately known in the trade simply as ACS. All gas fitting operatives take the ACS assessments, currently every five years. Several UKAS Accredited Certification Bodies undertake the assessments. These bodies provide substantial information to gas fitting operatives in an UKAS agreed format. In our case we used the well known CITB.

That information refers to FGA on one page only and makes it clear FGA must not be relied on for boilers with a cast-iron heat exchanger. FGA must never be used on back boiler units or warm air units. Their wording is clearly designed to discourage the use of FGA as a means of circumventing correct gas safety checks, which we all know is happening. We also know consumers who have queried this practice and have been told “we’re all using computers now”. That is the popular response. We say reject that answer vigorously.

The CITB offer two suggested figures for FGA C0/C02 ratio readings (0.004 and 0.008). We can confidently state that any boiler with combustion so poor that it reaches either of the prescribed figures, would be painfully obvious to the most inexperienced engineer, without the use of FGA. No question about that. There is no mention of how to use FGA. That is to say how to take readings. With a vehicle emissions test a probe is inserted into the exhaust pipe. It is not that simple with boilers.

British Gas literature we have seen refers to an annual check, not an annual service. Few boiler manufacturers prescriptively demand an annual service, though be warned, some do. Check your boiler literature. As far as we know, boiler manufacturers offer no definition for a check. If pressed they will refer you to their published service schedule. We will be examining the curious world of ‘checks’ soon.

The authorities seem to be clear about the generic aspects of a gas appliance check (?) and that must include physical intervention, therefore a strip down. FGA does not determine the need for a strip down and by the way, it never will in the foreseeable future. A strip down is ordained by default in any gas safety check.

If you are a consumer paying for an annual gas safety check by anyone, reject as unsafe any gas safety check which relies only on FGA. Such a check is worthless and indeed would be deemed negligent under the regulations. There are incidentally other considerations besides immediate gas safety.

Mark Clare’s assertion that FGA application halved the number of breakdowns is absurd. FGA will not detect anything likely to cause a breakdown that would not otherwise be obvious during the visual inspection he also referred to. We assume he refers to an internal visual inspection ?

FGA is sophisticated and accurate apparatus. Built and tested to exacting standards. It necessarily follows that use of FGA should be undertaken in a considered way. That is where the cause is currently lost. I call as my first witness the boiler manufacturers. Where FGA is mentioned, compare notes between manufacturers. There is no consensus and no simple generic protocol. This is why, in our view, there remains no British Standard. We are not convinced boiler manufacturers want to see FGA in the current climate.

Note with vehicles that approved testers always raise engine temperature to a specified minimum before recording data. One boiler manufacturer insists that if FGA readings are taken, hot water should be run for not less than ten minutes to allow the appliance to reach ‘thermal equilibrium’. Do you know anyone likely to do that or a customer who would not cringe at such profligacy.

Until there is a British Standard for use, which will then permit formal training, FGA must remain on the wish list. That said, even if there was a British Standard for use of FGA, the FGA probe would not become a magic wand that somehow wards off the potential to break down.

In all the years we used FGA only a handful of boilers reached the figures provided by the CITB. Those boilers were obviously in exceptionally bad shape. We knew they were bad and readings taken were for amusement only. Unless the FGA is a laboratory machine by the way, infra red gas analyser (portables are not) the CO2 is not sampled, it is calculated from the O2 reading.

If the introduction of FGA has suddenly allowed anyone to enjoy a massively reduced number of breakdowns (50%), there can only be one explanation. Mark Clare confirms they have abandoned the ‘traditional servicing approach’ and perhaps therein lies the clue.

The letter suggests FGA was able to detect what presumably the engineers previously could not. We don’t buy that argument which denigrates their engineers. It is well known that call-backs can occur following an intrusive boiler check or service because something has inadvertently been disturbed. This risk all Installers live with. It is not however a good reason to abandon intrusive checks.

Modern high efficiency technology is not necessarily synonymous with reliability as any experienced Installer will confirm. Wiser Installers may wait a while before launching into a new product range, giving others a chance to field test.

I am the first to acknowledge we must move forward but modern technology in particular demands an intrusive check as internal leaks are not uncommon. FGA will not recognise mechanical faults any more than a vehicle emissions test can report on the mechanical condition of a motor car. There is no difference.

We now know that boilers with cast-iron heat exchangers must always be stripped down but what about the others ? No boiler would be complete without a decent layer of dead creatures from the Lepidoptera and Hymenoptera insect orders. Some tenants may also meet with Orthoptera. Will FGA make those disappear and prevent them being pulled into an air intake serving a burner. I think not.

We know good people at the cutting edge who have expressed concern about target driven gas work. Concern has also been expressed about sales pressure and that subject is next on the Gas-News to-do list once we have completed our enquiries.

Note 1 – See the Gas Safety Review feature on the home page. That includes downloaded pdf files containing details of relevant Working Group meetings.