New FAQ is available.

[Roger]

The message from Andy Wade contains these words:

Possibly, but as I don't read German I don't know.

[Doctor Drivel]

Part L will be faster than boiling kettles on the Lancashire range as well. You really haven't got it have you. Currently Part L is 30 minutes, fast recovery is about 15 minutes. Is that so difficult for you to understand? You are misleading people into thinking they are getting a fast recovery cylinder with Part L when they are clearly NOT. There is a difference. Look at the cylinder companies. They have Part L cylinders and fast recovery using names like Ultra Cal, SuperDuty, etc.

It is NOT a semantic wriggle at all. One is 15 minutes and one 30 minutes. That is very clear.

If you can't figure this out drop the FAQ as it is misleading. Best no information than misinformation.

I can see this FAQ, being like so many others, full of personal prejudices, old wives tales and misinformation.

[Ed Sirett]

That's them.

[Ed Sirett]

20 minutes for 117 litre according to the spec in BS 1556.

The difference relative to what people have been used is immense. My usual problem is trying to get customers to install the minimum as required by the rules.

There is a difference. Look

In the absence of you producing your own offerings this is what there is. This matter is now closed.

[Doctor Drivel]

I said I would edit it for you - it is plainly obvious I know far more about the subject than you by about a million miles.

You have been told how it really is, rather than your misguided effort here and there. You now know HOW IT IS. So, no excuse at all.

Just drop it all. Better have no FAQ at all rather than one filled with misinformation and old wives tales. Stick to installing Valliant combis. Leave the rest alone.

[John Rumm]

There is much that could be covered that even the usual nay sayers don't dispute (even if they choose to gloss over when replying to posts themselves). The procedure for checking the mains flow rate is adequate before starting would be a good candidate.

A manual rad flushing procedure could go in a FAQ somewhere (although perhaps not this one)

[Phil Addison]

Well done Ed.

Some comments, mostly from a naive reader's perspective ...

"... try to get away with a cheapest nastiest boiler your installer is prepared to fit or try to make a repair that will hold out long enough."

This doesn't sit well in an article aimed at DIY.

"... the replacement is forced on you because you want a doorway where the boiler currently hangs."

You could just move the boiler.

"...any repair of less than £100 is worth doing. For boilers less than

20 years old allow another £50-£100 for each year less than 20."

So it is worth spending £850 to £1600 on a 5 yo failure? Cripes, how much does a new one cost?

"With Stainless-steel these don?t corrode either from the inside or the outside. I have been to at least one installation with a Silicon-Aluminium heat exchanger which was corroding inside despite the correct inhibitor being used. "

What is 'Silicon-Aluminium'? most people will have at least heard of stainless steel, but probably not Silicon-Aluminium. How do you tell which it is?

"The better units have a single heat exchanger with the burner pushing hot gases outward or downward through the heat exchanger."

Why is outward or downward better?

"forced pre-mix type"

needs explanation of what that means, why better.

"atmospheric type burners"

ditto, why worse.

"...has been modified to make it into a condensing unit."

This has the unsaid implication that this is a 'bad thing'. Why?

"All the condensation happens in the second heat exchanger (we hope)."

Why do we hope that?

"

"

Link broken.

"Sealed primary circuits are an advantage, see

This saves having these components elsewhere ..."

The list of components of an integrated system seems to be missing.

"Modern boilers need to keep the water circulating for a short while after the gas has cut off. "

Why? The paragraph could also mention the bypass valve, and (ideally) why it is better than the conventional bathroom radiator solution. It also means that all radiators can have a TRV (probably).

"There is one manufacturer who is a major player in continental Europe that we don?t have: ?Junkers?."

What is the significance of that statement? Is Junkers the only one not marketing here? Do ours market in the EU? Does it matter?

"... a large multiple unit house builder choose a particular make and model this is very significant."

In what way significant? Obviously good for the selected manufacturer, but is it good or bad for the consumer? Does it matter?

"End-users ? want the same make as any boiler they have been happy with and a different make to any boiler they have been unhappy with."

Anyone troubling to do sufficient research to find your FAQ might find that patronising. Perhaps qualify it as 'many end-users'?

"Left to the installers who have to fix there products ..."

their (typo)

"I know of one case where a manufacturer struck a deal with a gas training & assessment centre."

Are you suggesting this is a form of bribery (hence the title)? Hopefully the lecturer is free to point out the cons as well as pros of that particular demo model. Could it be that the training centre sought out a manufacturer that would give them a demo boiler?

"more demand means higher prices".

On the other hand, a large manufacturing run should lead to lower prices.

"There is a common boiler model which has a lot of trouble with its PCB. The replacement PCB is over £200 whereas most PCBs are around £100 give or take"

Name and shame them!!

"When it comes to boilers these arguments no longer apply."

Why not?

"Whilst the cost of exchanging a washing machine is about £50 the cost of exchanging a boiler can easily be £750."

Are these just the labour costs? I don't really see the point of this bit - it's surely obvious that there is a load of plumbing to do in replacing a boiler which doesn't occur for a washing machine.

"There is one exception. All the above ..."

I am not comfortable with this paragraph - it seems to indicate you are prepared to advise cheapskate practices, which the next paragraph says is not the case. Is the point that the installer should be prepared to ask about the future plans and advise all the options available?

"There is a ?grey? market for low end boiler installations ..."

I'm not sure it is a good idea to advertise this. It might encourage some types of reader to go and seek them out.

Phil The uk.d-i-y FAQ is at

Google uk.d-i-y archive is at NOSPAM from address to email me

[Peter Taylor]

This stupid remark highlights your ignorance. Why don't you just keep quiet and try to learn from people better qualified than you are.

The proportion of a boiler's output devoted to water heating at any one time depends upon many factors, the heat transfer rate of the coil being only one. Others include the temperature differential between primary and secondary, the boiler output capacity and any system controls and settings that prioritise between space heating and water heating.

A fast recovery cylinder is not "always the better choice". On a cold day like today, unless you have a boiler that is well over-sized, most of the boiler output is needed at the radiators, not at the cylinder. Anyone with a boiler that is struggling to keep up room temperatures today would be wise to switch on the immersion and allow the boiler concentrate on the rads.

Hahahahahahaha. This is from the guy who once argued there is no thermal gradient in the height of a cylinder!!

[Doctor Drivel]

Oh no, another Richard Cranium. Hoe goes on....

Powerful stuff eh?

Who might they be?

At least he has that bit right. He goes on....

He got that right too. He goes on.....

He got that right too. He goes on.....

Amazing. He got that right too. He goes on.....

Poor show. It had to happen, he got it wrong. For condensing boiler it certainly is the best chioce.

It has been coold. He goes on...

Not if the boiler is sized up properly. He obviously didn't know that. Also, a priority system that diverted all the boilers heat to the cylinder will reheat the cylinder in 15 mins and that is the worse case scenario. More likely a lot less time as in most cases the cylinder may not be fully exhausted. 10 minutes of the heating being off is not noticeable by the occupants, and when the boiler diverts to CH the boiler will work full belt to recovery the rads.

This one is a fool isn't he. If a boiler is struggling is best to add another boiler or get a bigger one as it is undersized. Boy is he dumb.

The above is sadly the case.

Rge fool laughs. helaughs he laughs, he laughs, he laughs.

Who was that?

..and yet another fool answered in uk.d-i-y. Isn't it fun.

[Ed Sirett]

Thanks for all the comments. Some of which are new. Some of which are already on my edit list.

As for name and shame. Why not try googling "Suprima lockout problems"? The price is truly amazing as the entire boiler can be bought for less than twice the spare PCB cost.

The new edit will have to address why there are some extra costs hidden in the process of having to submit building notices when a boiler is diy replaced. Mentioning that about the grey end of the market is only like talking about the fact that crimes occur it does not mean that I advocate such practices. The hard reality is that houses which are for sale and have had the heating 'fixed' for the sale will very likely be the worst end of the market.

[Phil Addison]

You are welcome, though I did read the other posts and didn't think I had duplicated any.

Tried a google web search and got nothing. A google group search threw up loads of discussions about Suprima but I didn't spot any specific mention that they were particularly expensive. Maybe it was lost in the noise - there were a LOT of hits.

That's why I said that the in next paragraph, it is clear that it does not apply to the work you do!

Perhaps the emphasis should be on how a prospective buyer could get an indication if the boiler has been 'fixed' rather that properly repaired, if that is possible? As it is, it reads as if there is no point in doing a 'proper' repair if you are selling up.

I had another look at the FAQ on your site but it looks the same. Will you post here when there is an update? When it is completed, do you want it to go in the DIY FAQ? If so I'll reformat it for you it in the style of the Power Tools FAQ.

Phil The uk.d-i-y FAQ is at

Google uk.d-i-y archive is at NOSPAM from address to email me

[Ed Sirett]

The new edit which includes sections on legalities of diy (it's not the gas fitting that gets you but building control). A glossary of boiler and heating terms.

I'm now at the stage of turning the references into links.

Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at

Gas fitting FAQ CH FAQ a Boiler FAQ