See also:

• Feature 14 (Building Regulations 2005) Part L
• Feature 15 (Building Regulations Scotland) 2004

We have permission to reproduce an email received from a consumer. The emailed question provides a useful platform from which to address a number of related and relevant issues. Consumers are our bread and butter so it is important their views are seen and heard as often as possible.

Quote

Dear Les

Please help. I am at the moment trying to decide which boiler to choose for my heating system. I have a small 2 bed detached bungalow. There is just my wife and I who live there although we do have showers everyday rather than a bath.

At the moment we have Economy 7 storage heaters, the hot water is provided by an immersion heater & hot water cylinder in the airing cupboard. Because space is at a premium we have chosen a natural gas combination boiler to be fitted where the hot water tank is at present, we would need the boiler to be vertically flued as it won't be on an outside wall.

We want a good boiler which will give us the minimum of problems, we don't mind spending a bit more on the boiler because hopefully it will be money well spent in the long run.

We have had four Heating engineers out to quote for the work to be done, so far within a couple of hundred pounds their quotes have been the same, the only problem is they have all said to use different boilers and "this is the only one I use because I have no problems from these boilers" is what we seem to hear from the majority of them.

Which is a big problem because which boiler should we choose? The makes given were Worchester Bosch, Vokera, Alpha, Glow-worm. When we spoke to a local supplier they advised Vaillant. Which only made our heads spin even more. We contacted CORGI for advice, they not to go for a cheap boiler, they aren't able to say which was a bad boiler, Which I guess is fair enough as they have to stay unbiased, I have searched the internet for reviews, but with no real success.

I have seen a few references saying that there are currently no industry figures about boiler reliability, which is poor because I am sure there are many people who are in the same situation as us.

Please can you give me any advice you can as we are really struggling and as the boiler is the most important part of the central heating system we are worried if we make the wrong decision now it will be a costly mistake in the future.

Thank you

Unquote

We receive a number of emails requesting advice on central heating and routinely refer those consumers to both the Energy Saving Trust (EST) and the Central Heating Information Council (CHIC). This is most applicable to anyone at the initial planning stage, lacking local advice. Having said that energy efficiency advice is relevant at any time and a heating system with good controls will automatically benefit the owner when insulation is upgraded.

Why the EST and CHIC ?

When you study the situation there really is no one available to offer impartial advice and as noted in the email, The Council for Registered Gas Installers (CORGI) quite properly remain detached. If pushed to point to contractors we refer people to the various Trade and Professional Associations listed in our Library.

The EST as most of us will know (?) sponsor the Energy Efficiency Advice Centres (EEAC) as well as maintaining the Installer Network. Installers are reminded that the CHIC work closely with the EST and operate the Installer ‘Best Practice’ training workshops. The latter are free and highly recommended. The CHIC is also home to BENCHMARK, the principles of which will no doubt in due course prove to be a key component in our answer to the consumer concerned and indeed others.

We must also point the consumer to the recent Building Regulations Part L (J in Scotland) changes and this topic is covered in our Part L (J) feature.

At the time of writing there is a huge weakness in the EST system. Knowledge of the EEAC is all but buried at their website. Anyone stumbling on the EST website is unlikely to become aware of the EEAC network. We know this is true from email received here. The EST may be losing a lot of potential candidates.

Although the EST is principally focused on energy conservation issues, most consumers we meet with are not initially motivated from that standpoint and this is significant. That is not to suggest consumers do not care about energy conservation. Regardless of any raging arguments over global warming there is nothing wrong with trying to save money on fuel bills and we now have the opportunity to do that in style.

It is time the EST and the CHIC sported a headline which grabs visitors desperate for advice on central heating issues per se. Once welcomed into that part of the website, those visitors can be conducted around the many relevant energy saving opportunities at the same time, thus the aspirations of both will be satisfactorily addressed.

Our consumer is faced with a dilemma. Each of the four contractors recommends a different boiler which, it is recognised, is central to the whole project; Actually it is not.

The boiler is certainly the most expensive component but the installation work itself will be the most expensive item and I would argue, is the most contentious and fraught with difficulty. Many if not most alleged boiler problems are actually installation problems.

No doubt manufacturer’s service departments could write a book on that subject. Having spent more than a decade trouble-shooting new build heating systems I could write a book as well.

Installers can in turn be faced with a dilemma on boiler choice. The relatively few suppliers we know have their own favourites for their own reasons. Merchants appear to be lowering their stock profile with cheap and not-so-cheerful tending to be pushed to the fore on all topics: For safety, Installers should do their own homework.

Installers also tend to be brand loyal. Many would argue this enables the Installer to develop a significant level of expertise on a small range of boilers. The UK is swamped with boilers. Manufacturers recognise brand loyalty is popular and maintain incentive schemes to seduce Installers. We ignore all those schemes and hopefully select a product which appears best suited to the needs of the particular customer. That certainly should be the correct way to choose.

Which is the most reliable ? No one can answer that question. Her Majesty’s Government own and maintain the Seasonal Efficiency Domestic Boilers UK (SEDBUK) database for which I am using the alternative URL here rather than sedbuk.com.

As a basis for discussion I would point out that currently there are many boilers which could possibly fit the choice made by our consumer. SEDBUK unfortunately cannot identify boilers with vertical flue options (?) That said we offer some statistics taken from SEDBUK today, using the following search parameters:

Currently in production > Natural gas > Combination boiler > Fan assisted > Room sealed

We have selected fan assisted as any room sealed vertical flue option must be fan assisted. We have specified room sealed as we could never again recommend an open flue boiler. Many of the following boilers may not have a vertical flue option. The figures still serve to show the staggering number of options available in the UK.

All options available = 226 boilers

All options with minimum efficiency Band B = 51 boilers

All options with minimum efficiency Band A = 37 boilers

Condensing only minimum Band B = 51 boilers

Condensing only minimum Band A = 37 boilers

Therefore all Band A and Band B boilers are condensing boilers.

For the interested, the most efficient current boilers listed of any sort are:

Oil - 95%

LPG - 93.3%

NG - 91.1%

Best of NG non-condensing using same parameters – Band D at 80.9%

My advice to this consumer would be to enjoy a day out at one of the imminent Plumbing and Heating Exhibitions (PHEX) which at the time of writing are listed on the EVENTS page. Judging from the hugely successful PHEX last year, a substantial number of key players will be present and can be interrogated on the day.

Our Library contains a list of websites which offer good boiler information. If any names are missing please let us know. Gas appliance manufacturers are listed separately but the list also includes appliances other than boilers. Our list of boiler manufacturers (at the time of writing) is set out below but will not be complete:

Vokera > Baxi Heating > Ideal > Halstead > Atmos > Ravenheat > Eco Hometec > Worcester- Bosch > Servowarm > Glow-worm > Potterton > Vaillant > Chaffoteaux et Maury > Saunier -Duval > Ariston > Biasi > MHS Boilers > GrantUK > Keston > Powermax > Ferroli > Alpha (web site under construction at time of writing)

Aside from reliability, all modern boilers should offer 2 year guarantees as standard. I would accept nothing less and this is one of the benefits of EU membership. The problem now is the vast range of features available on many modern boilers which I am not competent to catalogue. Can I request our expert Installers bombard us with advice on the options available now, with combination boilers. I cite as historically basic examples:

• Built in boiler frost protection
• Stored hot water
• Hot water pre-heat
• Varying hot water volume
• Modulating gas valve
• Anti-cycling devices

To be accurate, each of the four contractors mentioned above has quoted not a boiler but a manufacturer, if that information is complete. Not good enough and concurs with the limited evidence we have to date. Our consumer needs to know precisely which model is on offer for their money. Nothing less than the model identifier is demanded. Better still, the consumer should have a brochure on the boiler concerned, as the same consumer would expect when purchasing a motor car or white goods.

Gone are the days of the African Queen. The floor mounted denizen of damp utility rooms chugging out heat no matter what malady the system suffers from. Aging pumps, lack of controls, leaks, galvanised tanks, uninsulated hot water cylinders and radiators clogged with magnetite. True they will plod on forever but at a typical 55% system efficiency would you really want it to ?

Some reading this may one day know grand-children denied the freedom of choice we take for granted today because of our profligacy with fossil fuels. Hopefully the wise will prevail. Both Scotland and Wales can show us the way forward with renewables but until that dominates we can all help progress in favour of common sense. For further reading see our Library.

So far so good but we have not addressed the key issue affecting future performance and reliability of our consumer’s heating and hot water provision. That is to say the most expensive bit. The installation.

Anyone can cobble together a heating system and fire it up. Boilers today are Installer friendly, built and tested to exacting standards. What could possibly go wrong ?

They do have foibles. The very rare gas safety alerts are flagged in The Gas Installer, magazine published by CORGI and free to those who choose not to ignore Her Majesty’s Government by proving competence and registering as a gas installer in the appropriate category for boilers. That is one mandatory safety net for consumers not to be ignored.

Often termed competence destroying innovation, there are many associated products designed to enhance installation but too often they fall into the hands of those lacking the necessary design knowledge and thus systems inevitably suffer, with the boiler usually being blamed.

Modern systems should be regarded as a super-organism (my view) and the various parts should not be considered in complete isolation. There are associations and bodies for all parts of a heating system, representing various industry interests. Controls manufacturers, The combi boiler club, The copper development association and others.

No one I know represents the birth of the super-organism. There is no midwife. That should perhaps be the role of the Trade and Professional Associations but they jealously guard their own patches in our green and pleasant land. That continued parochialism thwarts any prospect for improving consumer protection. Their various daft schemes have proved useless aside from short term self-aggrandising publicity.

Everyone knows that and whispers abound but the only person brave enough to comment was Barbara Field in her parting gesture as Editor of Heating and Plumbing Monthly. Now safely ensconced as Editor of Heating, Ventilating and Plumbing, the publishers of which, B & M publications, organise PHEX.

There is a glimmer of hope in the guise of BENCHMARK. Fiercely non partisan, Benchmark recently stamped on a misguided few who were attempting to use that well known ‘brand’ to enhance their greedy and self serving marketing ploys.

Benchmark does not have a list of ‘Approved’ anything. They allow manufacturers achieving a recognised standard to promote the principles of Benchmark in favour of good installation but that does not mean in turn that the companies are Benchmark ‘Approved’. A difficult concept to grasp. Time it was clarified.

Benchmark is we hope pivotal in the war on competence. It is a philosophy that actually once existed before but has been lost largely due to the incompetence of those, past and present, who have set themselves up as experts in the field of training.

Largely gone is any semblance of handed-down professionalism in what is ironically a far more technically challenging environment. That would never have happened if there had been but one professional association but industry is now dominated by unskilled pen-pushers relying on DIY perceptions of contracting.

There is much superb technology to be enjoyed in 2002 and enjoyed is the correct term for all concerned. There is no greater delight and satisfaction than the birth of a truly efficient response to a demand for heating and hot water. Note the word efficient. Efficiency is primarily underpinned by insulation with everything else following on. That is the correct philosophy and sequence adopted by Best Practice training.

Trade Magazines too often criticize Installers for allegedly avoiding modern technology but I have yet to see one of those journals promote the whole ‘Best Practice’ model and message: Pecuniary interests rule - OK.

Modern boilers are supremely efficient when firing but modern philosophy seeks to minimises boiler firing, which is even better. Environment saving, fuel saving and less wear on the boiler. Electronics boffins will know that components such as relays are rated in quality according to the average number of actions they can expect to perform in their lifetime. Any reduction in actions performed must therefore aid longevity. A key component on heating systems is the boiler interlock or room thermostat. No excuse for ignoring that low cost option. And there are now wireless products to avoid disturbing the new wallpaper.

Combination boilers in particular are high rated appliances. Many are more than twice the rated input of the boilers they replace on old systems. Burner demand is less frequent but when demand is present a lot of gas is required quickly. Gas pressure is a fraction of one percent of water pressure thus any pipe resistance will be significant. One of the tragically basic faults on many systems is failure to upgrade the gas supply pipe. 22mm pipework is an absolute minimum in all cases. Sometimes 28mm is demanded en-route to a new boiler.

CORGI registration is principally concerned with gas safety but the skills learned in support of that aim necessarily provide the Installer with a great deal of knowledge on the subject of combustion. Good combustion is safe combustion. Safe combustion is good combustion. The two desirable objectives share a common pool of knowledge and that knowledge helps the Registered Gas Installer ensure the boiler is correctly set up.

An Installer needs to understand how to measure and where necessary make arrangements to correct gas working pressure at the meter. Without that is correct the best technology in the world will not deliver promised potential. Without correct pipework the working gas pressure at the boiler will not match the correct working gas pressure at the meter. Boilers with direct burners (no pilot light) may fail to light in the absence of satisfactory working gas pressure and these boiler serve to highlight the problem.

Connecting boilers to radiators may appear simple enough but particularly with copper pipe my competence destroying innovation concern applies. Personally I only stock flux which is suitable for both gas and other purposes. That is to say (self cleaning) flux that is only active when heated. Similarly I only stock lead free solder though that is only required (mandatory) on potable systems. I.E. hot and cold water that may in some way be consumed. Checking solder roll end labels will confirm the choice of solder being used.

Aside from the circulator (pump), modern combination boilers uniquely contain moving parts which are intolerant of system debris. That includes flux, PTFE tape, stamping oil, casting sand etc. Some might argue cold and hot flushing is sufficient on any new system. For what the cleaning materials cost is it worth denying that option ? A disciplined approach to cleaning is required also if it is to be effective. Draining from one radiator cannot be effective, particularly with modern drop-fed systems. That is to say systems fed from above.

Catered for with a couple of fittings costing pennies, even a new system can be quickly power-flushed. Everything will be new and fully functional. With some experience, power-flushing is a breeze but it must follow a disciplined approach and that includes flushing every radiator by the simple method of operating valves.

Once cleaned, every system must be treated with inhibitor of choice. The popular expression ‘always read the label’ never applied more forcefully. Inhibitor can put a passivation on the inside of radiators and must be topped up if radiators are drained at any time in the future. The cost of inhibitor is almost negligible in the overall equation.

Room thermostats (boiler interlock) are an aid to both economy as well as efficiency. Thermostatic radiator valves (TRVs) are popular and a valuable aid to economy rather than efficiency. Some condensing boilers may not mourn the absence of TRVs. Many combination boilers, condensing or non condensing, may prefer to see at least one radiator without a TRV. Typically the bathroom radiator is selected but it is also usual not to fit a TRV on the ‘register’ radiator. The register radiator is the one in the room (usually the hall) where the room thermostat (boiler interlock) is sited.

Some may of course have selected underfloor heating which, thanks to floor insulation, is now enjoying a comeback and is particularly suited to condensing technology. Being relatively new, underfloor heating is not as widely understood but Installers can benefit from manufacturer’s design services and so will not be alone in any project they undertake. In this arena at least my super-organism is nurtured.

Combination boilers seem to be well understood but for the benefit of anyone new to the subject they are typically fitted to a sealed system (also called unvented) and heat hot water as it is drawn. It is the latter that demands the power like a multipoint instantaneous water heater.

Less well known perhaps are the thermal store combination boilers (freestanding) such as the Powermax which has a water to water heat exchanger for heating water as it is drawn, with potentially high mains pressure flow rates.

Combination boilers are available as condensing combination boilers. Condensing boilers have a non-ferrous heat exchanger and extract heat from flue gases which is ordinarily lost. For the small extra cost it is the obvious first choice where installation permits. Condensing boilers plume (like steam from a kettle) and need a 22mm plastic pipe to discharge condensate to a convenient drain, preferably inside the building. Vertical flues can be particularly helpful where pluming may otherwise be a problem.

I am still unable to offer any help on the question of reliability. Price may not necessarily be a guide. Less expensive boilers may simply offer less features rather than less functional quality. Only time will tell. We can however say for certain that statistically, a carefully installed system will last much longer, trouble free than a system which has been thrown in.

Insulation is still the poor relation in my view. Plenty of scope for successful DIY in support of that. The most familiar and logical place to begin is the roof space. As I often say, all standards are minimum standards. Every contribution to insulation brings savings and sub-floor pipework is easily fitted or upgraded with modern pipe wrap as I did recently at home.

Although I have waffled on a bit to address a wider audience there are still I hope many useful pointers above to help our consumer ask the right questions. The consumer needs to know precisely what is being offered for their money, in all respects. Boiler options can now be sourced independently by researching sedbuk, manufacturer’s websites and PHEX.

The risk of buying a lemon or Monday morning boiler can never be eliminated but other risks can. In some ways boiler manufacturers are their own worst enemy. With two year guarantees becoming the norm they must despair at the prospect of warranty calls provoked by poor installation. Aside from one H&V company no one in the boiler market seems willing to take the bull by the horns and deny warranty claims arising from poor installation.

Manufacturers can often provide free product training for Installers and continue to promote Benchmark for which they provide the consumer with a log book to encourage careful installation and future maintenance.

Manufacturers also provide the most beneficial service and maintenance support where required. Their expertise and stock profile must be second to no one and we strongly advise customers to take up that option.

Editor’s Note 25.09.2003 - We get a huge number of hits on this page. If the Comment does not address your reason for stopping by, please send us an email and let us know with reasons.

Editor's Note 24.03.2007 - I repeat this has been reproduced for historical reasons. Seek more up-to-date information at   www.est.co.uk.