DIY Doctor

Gas Central Heating Boilers

Postby The Heating Doctor » Sat Sep 15, 2007 11:08 am

One of the most frequently asked questions on this board is what boilers would we (we being the trade’s people who take time out to assist users of the forum) recommend. This leads to all sorts of boiler models and manufacturers coming forward. The cast of good, bad and the indifferent boiler models then leads on to some more debates. I have no doubt that every boiler recommended will be done so in good faith, as no one sets out to recommend a bad or indifferent boiler. For heating engineers; those who install boilers if a boiler when fitted fires first time and then causes no further problems during there (the installers) warranty period then it’s a good boiler. However there is more to boilers than many people suspect, since the change to Building Regulation Part L (England & Wales) 2005 condensing boilers have been required to be installed, with few exceptions in all new boiler installations within domestic properties. A few boiler manufacturers where not exactly ready for this change as there had been uncertainty virtually to the last minute as to whether or not this change would be implemented. When the change was announced this left these manufacturers in panic mode and with little time. As a stop gap they retro fitted existing non condensing boilers with a second heat exchanger to turn them into energy band category B condensing boilers. Several major problems with this are that very little R&D was done on these boilers. They are not as efficient as purpose made condensing boilers. Also significant is that the heat exchangers are made from aluminium, a material that is not resistant to condensate (the bi-product of a condensing boiler) and therefor the heat exchanger will fail long before it would have been expected. This all adds up to additional cost to the householder in the form of more expensive fuel bills and repair costs. Baxi Potterton where the worst offenders for this type of boiler as they took previously well liked boilers such as the 105e and turned them in to this B band cobbled boilers. Part two of the operation was to see them sold out so cheap that they have been bought by the thousand, most will get through the standard 1 year warranty so Baxi Potterton will have no come back on them. This was so successful that it forced other boiler manufacturers to cobble B band boilers so they could compete with the Baxi Potterton boilers. The Alpha CB range for example did not appear until almost a year after the Baxi 105he. These boilers are cheap, but they are cheap for a reason and I would advise every one to stay well clear of them. My final word on these boilers is that Baxi no longer advertises this boiler on their web site, what does that tell you.

Condensing boilers however are not all bad news, look at the new comers to the UK market, companies such as Viessmann have a superb range of boilers. Three-year parts and labour guarantee as standard or five years if the installer has attended the Viessmann training course. This company has been manufacturing gas-condensing boilers for over 25 years and has NEVER had a heat exchanger fail! That is why on the heat exchanger, they give a 10-year guarantee regardless of who installs the boiler, as long as the installer is CORGI registered. Even better news is that the boilers are 97% sedbuck band ‘A’ energy efficiency rated (Baxi 105HE just over 86%). Vaillant have come of age, their tired UK only boilers have been replaced by the German developed condensing boilers. Alpha CD range is also another to check out. Now that Baxi have taken the time to develop a condensing range the Platinum range is worth a look at with its five-year guarantee. If your budget is limited the Halstead Ace HE is worth a look, this sedbuck A band boiler has a B band boiler price tag but just creeps in at 90.7% efficiency and has a two year warranty parts & labour. You will notice there are some big names missing from my list such as Glow-worm, who have had major quality problems, the flexicom being the latest model to have such problems. After sales, is also terrible, just getting some one to answer the phone is a major achievement. Ideal boilers, the entire range is over priced and all boilers are manufactured with an aluminium heat exchanger. Worcester, have good reliability and name, however they are expensive and the aluminium heat exchanger is again cause for concern. The block, from which the exchanger is manufactured, is thicker than standard exchangers to with stand the corrosive effect of condensate. However, where will that aluminium that will corrode off the heat exchanger end up in the heating system. It could lead to the steel of the radiators and the aluminium reacting to one another, which in turn will result in the radiators failing by pit holing. That is conjecture based on past experience of mixed metals reaction, something that most heating engineers will have witnessed, but only time will tell on this one. So, there you have my summery on current boilers of any note. This is based on over 30 years of experience with in the industry of which the last 20 have been as a technical support engineer, the guy the heating installers turn to when they need advice. Do with it as you will, at the end of the day its your money and your home. Remember that when a heating installer recommends a boiler it is not unusual for it to be for his benefit and not yours. Do the research look in to warranties, ask to see their CORGI card, ask for references and never give money up front.
The Heating Doctor
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Simply Build It

Postby htg engineer » Sun Sep 16, 2007 11:40 am

The organisation I work for own over 19,000 houses, we install the Baxi 105HE and the Potterton Promax.

Because we own and rent out these properties we are responsible for the annual gas servicing and repairs of boilers and central heating systems.

So how does

[b]those who install boilers if a boiler when fitted fires first time and then causes no further problems during there (the installers) warranty period then it’s a good boiler[/b]

explain why we fit these boiler ? we have to install them, repair them and service them for many years to come.

It wouldn't be any good or make any sense for us to install poorly built boilers as the repairs and maintenance costs would be through the roof. We have had no bother with Baxi or Potterton boilers.

Thats why I recommend them, and thats why i'd have one in my house - who knows my views may change in a few years if you're right about the heat exchangers. We'll have to wait and see.
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