Confirm/deny boiler fault?

I'm told the boiler heat exchanger is partly blocked, laeding to the flame coming out sideways, licking round the edges of the the combustion chamber. Is there any way to confirm/deny this, as visually I cant see anything? The exchanger itself is not visible.

Last time I saw it alight through the viewing window, it looked fine, with rows of neat upright blue flames.

thank you, NT

Reply to
bigcat
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What colour are the flames - are they still blue - or are they yellow? If the latter, there could be some crud in the burner rail, interfering with the proper gas/air mixture.

Otherwise, it sounds as if either the heat exchanger is sooted up, or there's a problem with the flue. What boiler is it?

Reply to
Set Square

blue thankfully. There is a 3mm tide mark of what looks like well burnt paint round the outside near the bottom of the combustion cavity, which he says shows its burning, and the metal cover on the pilot light is discoloured. Also theres a light scattering of white ash on the base of the thing. Thats the evidence. I cant help being less than 100% convinced, and I do need to know whats what on this and act on it quickly.

Balanced flue glow worm fuel saver, quite an old one, may well be

1970s. Looks very basic, no protection mechanisms of any kind as far as I could see, just a gas solenoid, pilot light with ignition and thermocouple, and a knob to adjust heat output.

And I gather it may be not sealed, I had assumed it was. It looks like a sealed box, but the cover just presses on, and could be better.

If its nothing more than soot in the exchanger, can it just be poked clean?

Thanks!

NT

Reply to
bigcat

An old Elan is it? The fins get clogged with crud and soot then even though the burner operates fine the flame/hot gases cannot get through the fins so they lick out around the skirt of the combustion chamber. Easy to see when the outer casing is removed. Cleaning the fins properly is a very tedious job requiring scraping every single fin and passage:-(

Reply to
John

Yes, sounds like an exact description. Its a Glow worm, probably 1970s. If the heat exes are cleanable I'm up for doing it, will be far quicker and cheaper than a new boiler.

NT

Reply to
bigcat

I imagine that a certain amount of dismantling will be required.

I used to have to clean an old Baxi Bermuda from time to time. That had a cast iron heat exchanger, in two halves - like chunky chocolate bars facing each other. You had to slide out all the control bits - complete with burner rail - from under the heat exchanger, and then use an over-size bottle brush up the middle of the heat exchanger to remove all the soot.

Yours is almost certainly constructed differently, but the general principles will be similar.

Reply to
Set Square

I am concerned that the cover just pushes into place it should be room sealed. You say a balanced flue i.e. a largish rectangular metal terminal on the wall outside at about the same height as the boiler itself? If so the cover should be held by four threaded studs (on the cover) which are secured by four wing nuts at the rear of the boiler.

If the flames are blue then cleaning out the air heat exhchanger should fix everything.

Reply to
Ed Sirett

Who was it that told you? British Gas?

Reply to
Mr Fuxit

Thats what I thought. There is certainly an attempt at a seal, but whether its airtight I dont know. The front of the boiler, ie just the front sheet of the outer casing, not the other 3 or 4 sides as well, just presses home into a rubber strip round the edge. Thats it, no screws, nuts, etc. It is old, 70s or maybe early 80s. I suppose for all I know it might even be older.

yes, definitely balanced.

Its nothing like that.

Ooh :) OK, how to do this: drain system, figure out how to remove exchanger, figure out how to clear it and reassemble. Then if it works ok, get a retest before using it.

thank you, I was hoping you might give some input :)

NT

Reply to
bigcat

I'd be very surprised if you have to drain the system and actually remove the heat exchanger to clean it. Most boilers are designed in such as way that routine servicing can be carried out without draining down.

Reply to
Set Square

Nothing quite so drastic. You should be able to clean out the gas side of the heat exchanger without removing it from the boiler, and you won't need to touch the water side at all. An over-grown bottle brush available from some boiler spares shops/plumbers' merchants will help.

However given the uncertainties of the safety of this boiler and your modest experience I recommend you get someone to look it over even if you do the cleaning out yourself.

I always think the term 'Space Saver' saver has become ironic as it is (now) one of the largest wall mounted boilers you will find.

Reply to
Ed Sirett

no, I would touch them. (I've yet to really confirm it is.) But yes the guy who did it quoted me for a new boiler... call me a bit cynical.

NT

Reply to
bigcat

nice one :)

Oh I will.

The only problem is I cant see what Im doing, cant actually see the heat exchanger at the top at all. And since I've never worked on one I dont know what size the gaps are in the exchanger, now how deep they go

- but I'll see what I can do, starting with a little bottle brush tomorrow, and upgrading to a plumbing merchant one.

Thanks.

NT

Reply to
bigcat

If it can be removed, what about a pressure washer?

Reply to
Ian Stirling

I had one of those... as you say quite basic.

IIRC it is sealed, although I have a slight recollection of there being something a little unusual about them that was mentioned by (possibly) Ed in the past - needless to say can't find the post now.

Depends on if it the soot that is holding it together I guess ;-)

Reply to
John Rumm

SNIP

Well yes it "can" be removed but to clean the dry side of a heat exchanger even tediously its a lot less taxing than draining down, removing the heat exchanger, pressure washing it, reassembling only to find the old seals are brittle and irreplaceable, thus having to chuck it away and replace it anyway is a lot more than any tedium in cleaning. Of course you "may" be able to do the job in situ but dont forget the damage you may cause to refractory parts. with the high pressure jet.

Reply to
John

Usually there is some sort of cowl over the top of the heat exchanger which is removable, typically by a few screws and/or wing nuts. When this is removed then the top of the heat exchanger is complete exposed.

Reply to
Ed Sirett

Big thanks to everyone that helped with this. Its all passed fine, and I saved myself from a 4 figure ripoff. Cheers!

I expect I've helped others do the same somewhere along the line.

NT

Reply to
bigcat

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