New FAQ is available.

[Ed Sirett]

I've knocked up a first draft of a new FAQ. This is about choosing a particular make & model of boiler. It is not about selecting a particular method of heating or HW production. Nor is it about how to choose a particular size of boiler.

As always comments and suggestions will be taken into account. I expect there's a stack of typos and loads of scope for graphical and linguistic style changes.

Hopefully this FAQ will help regular posters with responding to some of the quite frequent questions like "Why won't anyone fit an exact replacement for my floor standing boiler?" a bit easier and simpler.

I think respect and congratulations should go to AH, CMcA, SS, t and many others who often and repeatedly takes trouble to explain many details about choosing a boiler. This subject is often complicated by the web of regulations especially the latest Part L stuff, Part P, Part G. Having a lot more on the subject than is ever included in any one post should be a useful resource.

I am aware that this FAQ naturally wants to have a "choosing a type of heating system section". I am definitely being coy in this area:

1) The matter is dealt with, albeit rather basically in the main FAQ. 2) There's an effin' difference of opinions. 3) I'd much rather try to produce "The Boiler Diagnosis and Repair FAQ." My inspiration is Sam "Silicon" Goldwasser of sci.electronics.repair.

[The3rd Earl Of Derby]

(puts hand in the air)

Can I make a suggestion... How about an archive of scematics and manuals for any CH boilers scanned by members of the group for every boiler that is available if people have them and email them to the DIY faqs site for which people can DL them if and when they need them. This doesn't stop here on just boilers it could also be out of print scematics of most consumer related products.

I have a worcester boiler manual which is very usefull and covers the boiler parts in detail.

Any thought.

-- Sir Benjamin Middlethwaite

[Ed Sirett]

I have a CD set (from Ebay) which is probably a rip off from the CORGI product costing hundreds. It has about 500 boiler and gas fire manuals as PDFs. It tends to be skewed towards the more recent models. It's much less useful than I was hoping - pleased I didn't shell out for the CORGI version.

The manufacturers will send out (they are probably obligated to do so) the manuals on request to owners of their boiler.

[Doctor Drivel]

"If the HW cylinder needs to be replaced then it too will have to comply with new regulations. The new cylinder itself will comply (it will be adequately insulated and have a 'fast recovery' indirect coil so that the water is reheated quickly). The surrounding pipework will have to be insulated as well."

The cylinder will comply with Part L, which is 'not' fast recovery. Fast recovery is a bigger coil again and generally heats a cylinder in 15 minutes not 30 minutes as Part L does. Fast recovery is always the better choice.

[Doctor Drivel]

The cylinder will comply with Part L, which is 'not' fast recovery. Fast recovery is a bigger coil again and generally heats a cylinder in 15 minutes not 30 minutes as Part L does. Fast recovery is always the better choice as it will dump in most cases, the whole output of the boiler into the cylinder.

Generally yes. But W-B make a very good silicon aluminium heat exchanger. Ideal do not.

Depends on application

Depends on application

Depends on application

Yep

Yep.

Yep.

Yep.

Also:

- one piece heat exchangers

- Horizontal or downwards firing pre-mix burners. Pre-mix burners tend not to have a fan in the flueways.

Extra features:

- depending on application, 'load compensating' burner modulation

- depending on application, integral outside weather compensation control.

- long guarantees, such as 5 years, which many makers now offer. Some offer

2 years on the boiler and 5 on the primary and secondary heat exchangers.

Silicon coated aluminium is no drawback, depending on who makes it. Worcester-Bosch use them in their new models. They are slightly more efficient than Stainless. Non-Silicon coated Aluminium is a drawback

Yep, sometimes called recuperators.

Yep in condesning boiers. In non-condesning boilers they are not a draw-back.

Yep. In 'condensing' boilers.

[John Rumm]

Very good it was too. Thanks Ed.

I felt a little more information on Modulation would be helpful - the role it plays in modern heating system design, the impact on boiler sizing etc (perhaps a section on sizing might be worth having also).

[Andrew Gabriel]

Looks good. Only a couple of nits...

nntp://uk.d-i-y should be news:uk.d-i-y

Under 7.2 "Installers" You should probably add "familiarity", and that there are sometimes deals for the installer when he's bought a certain number of one make. These issues are likely to influence the choice. (You do mention this in Section 10, but you also mention it in 7.1 for "Specifiers".)

You might want to say up front (to avoid later disappointment) that you are not going to be telling the reader what boiler to choose.

[Dave Fawthrop]

| I've knocked up a first draft of a new FAQ.=20 | This is about choosing a particular make & model of boiler.=20 | It is not about selecting a particular method of heating or HW | production. Nor is it about how to choose a particular size of boiler.

Wonderful piece of work. :-)

As you have included. Help! Help! my boiler died, etc. you have included replacing an existing boiler. How about a section on cleaning out the crud from the radiators etc.?

--=20 Dave Fawthrop Some of my Hobbies: VDU Glasses=20

Wordlists Celtic fonts=20 Killfile&Anti Troll FAQs Dialect Curry Project, =

[Andy Wade]

Excellent - here's my two penn'orth:

"The gas boiler is a unique appliance in that it is the only appliance which is connected to all three mains services."

Make that four (drainage)!

"5. Why are (good) boilers so expensive? [...] the folowing are some possible factors." ^^^^^^^^ sp: following

"Of course washing machines need type approval [...]"

Not AFAIK. They need to comply with the relevant safety and EMC product standards and be CE marked, but it's not a type approval process as such.

"Integrated pump: [...] The down side is that when it fails the pump will very likely be customized unit for the boiler"

... a customised unit ... (insert "a", others can debate s/z spellings)

"7. Marketing: Truth, lies and bribes! [...] "There is one manufacturer who is a major player in continental Europe that we don?t have: "Junkers"."

Don't follow - did you mean "one type of manufacturer" who only produce junk?

Two other suggestions:

1. You could make the contents list into hyperlinks to appropriate bookmarks in the document.

1. You could add a (simple) glossary of terms. For the intended audience this should cover quite simple terms (along the lines of "the naming of the parts") and would help the reader interpret what their installer is saying and help with bullshit detection. It would also be a way of covering the subject you're being so coy about - the difference(s) between 'system' and 'combi' (etc.) boilers, simply stating what they are in a non-controversial manner.

[Tony Bryer]

Looks pretty good to me: rather than do what some of the others have suggested wrt manuals etc, what about ending the page with links to manufacturers web sites?

Also

gives online access to the SEDBUK boiler efficiency database

[Alan J. Wylie]

Indeed.

RFC 1738[1], section 3.7

| A nntp URL take the form: | | nntp://:// | | where and are as described in Section 3.1. If : | is omitted, the port defaults to 119. | | The is the name of the group, while the is the numeric id of the article within that newsgroup. | | Note that while nntp: URLs specify a unique location for the | article resource, most NNTP servers currently on the Internet | today are configured only to allow access from local clients, and | thus nntp URLs do not designate globally accessible | resources. Thus, the news: form of URL is preferred as a way of | identifying news articles.

so the nntp:// form *requires* a server, a newsgroup, and an article reference, and the example given above is not syntactically valid.

[1] ftp://ftp.rfc-editor.org/in-notes/rfc1738.txt

[Andrew Gabriel]

I don't think the nntp: form is widely used or implemented, due to it not being very useful.

[Roger]

The message from Andy Wade contains these words:

Now you know why they have given up here even before they have begun. :-)

[Andy Hall]

Good idea. There are also some Word etc. documents there with details of how the specs are written.

[Ed Sirett]

A compliant part L cylinder will be faster recovery than almost anyone (especially anyone who needs a cylinder replacement) is used to. This semantic wiggle is not upheld for the next edit.

[Andy Wade]

Even more confused ... Google ... oh, is

relevant here?

[Ed Sirett]

Agreed about sizing. I think we can approach that subject without falling into the snake pit of combi v. stored. HW

I think an Appendix relating some of the stuff from the energy efficiency council. On how older boilers waste energy.

This would have to deal with the impact of fanned flue v. balance flue v. open flue. Permanent pilot lights. Modulation. Boiler controlled pumps and boiler modulated pump speeds. Anti-short cycle delays.

[Ed Sirett]

No problemo.

I've seen deals like this on pumps. I've yet to be offered any such deals. OK I got a Vaillant fridge magnet one year.

OK. ...not which make of boiler...

[Ed Sirett]

I think if I ever get enough round tuits together for my Opus Magnum on fixing boilers a complete section on "Power Flushing: who wins?" will be called for. Sorry, my view is "not in _this_ FAQ".

[Ed Sirett]

Well spotted.

No I mean the manufacturer that also makes/used to make aeroplanes. Apparently they are really big in continental Europe. I think we don't have them because Vauxhall discovered Novas weren't popular with the Spanish - Nova meaning or suggesting to the Spanish the car didn't go.

I'm editting with Open Office and saving as html. I'll need to find out how its done.

Thanks. I have realised that I have been spending an inordinate amount of effort to carefully circle around this aspect of the subject. Frankly, it has gotten in the way. I think I'm going to bite the bullet the worst that will happen is that some people will post criticism of the FAQ whenever it is referenced. This might defeat the objectives enabling better answers, with less effort and reducing bandwidth usage. However those disgruntled with my opinions will have to make their own FAQ (a process which they seem unwilling or unable to do). I will however try to be as neutral as I possibly can.

The Sealed CH FAQ has worked. We have had a big reduction in the length of threads on that subject and we have not had to spend time putting half right posts.