Help, sooty boiler

[Mike Faithfull]

Help! I'm in trouble - The Management's away and if I don't get the boiler fixed by her return on Friday I shall really be in the .. er, .. you know!

Old (guessing 15 years +) Potterton Kingfisher CF60 boiler was smelling a bit, so I thought it was due for a clean. Wasn't too worried about the smell, 'cos it's in a little closed room with its own air vent, but I haven't done anything to it for a couple of years, so decided to do a "service" ...

Took the front off the combustion chamber and found a big sooty lump - sort of cone-shaped, about 2" dia at the base x about 2 1/2" high - hanging down (pointy bit towards the floor) from the left hand end of the heat exchanger. I removed it and generally brushed and vacuumed everything clean, fitted a new thermocouple and re-assembled. Unfortunately, the burner flame is very yellow, and the fumes are worse than before.

I did kinda expect to have to replace the boiler before long, but with the cost of Christmas and a big bill from the car menders last week and (pout, whinge, self-pity etc.) I really can't afford to do so right now. Any instant fix??

[Andy]

Hi,

The first thing you need to do is turn it off......... That means right now! Your Potterton is putting yourself and the rest of your family in real danger of carbon monoxide poisoning, especially as you can smell fumes. Then get a gas engineer in to sort it

Andy

[Dave Plowman (News)]

You need to remove the top cover as well, and use a pukka flue brush to clean the heat exchanger thoroughly. A heavy duty vacuum cleaner will help to keep down the mess. ;-)

I also remove the burners and give them a good soak in hot water and washing up liquid, and scrub clean with a nailbrush. Examine the jets with a magnifying glass if necessary to make sure they really are clear after this.

Make sure any gaskets are undamaged on replacement - you can buy the generic material used for them at a PM - along with the flue brush.

These boilers go on forever. If it starts leaking, it's usually the 'O' rings between the heat exchanger segments that have failed, and these can be replaced.

[Andrew Gabriel]

Yes, a proper service, of which you did only one bit. I suggest you call in a CORGI to service it, as you don't seem to meet the legal criteria to service it yourself.

[Dave Plowman (News)]

The first time I used a 'CORGI' for a service - got from Yellow Pages - he condemned the boiler and left it in pieces. Said it was incorrectly installed, burning the floor and had improper ventilation. (It's an RS) And it would be cheaper to simply replace it.

Contacted Potterton and they said he was telling lies, basically. Not surprising given it was installed by a very experienced fitter - unfortunately by then retired.

Since it was in bits, I cleaned it all up carefully, and replaced all the gaskets which he'd wrecked - and needed new screws for the front which he'd obviously taken with him.

Still working fine about 20 years down the line - I just give it a good clean every few years and keep an eye on the colour of the flame.

[Andrew Gabriel]

Yes I know a lot of CORGI's are not trustworthy (had experience of one who condemed my grandmother's boiler when it only needed a new thermocouple). However, if someone asks questions who is clearly not going to come under the compitency requirements of the law, it's difficult to think of anything else to suggest, although I like your idea of calling the manufacturer which I hadn't thought of.

I didn't think it was safe to suggest the person service the boiler themselves. At a minimum they need the boiler servicing manual, and to understand it. Your advise went a bit further than the original poster's efforts, but failed to mention things like checking the flue, which could be the cause of the problem, and life threatening. The system needs a complete service, and not just doing one or two things until it seems to be working again whilst some fundamental problem may remain unnoticed.

[Mike Faithfull]

Thanks Dave (and others) ... I have taken heed of your reply and am about to re-assemble everything after stripping out the burners and supply pipe etc to give them a jolly good wash in the kitchen sink. None of the holes were blocked as far as I could see, but there was a lot of powdery residue on the inside of the burner tubes. A friend locally suggested I should check for an obstructed flue, but that would not account for the properties of the problem - the combustion chamber would be much more evenly sooted up, not just at one end. I need to take a little more care, I think, to ensure the heat exchanger is cleaned - I didn't take enough time over it last night.

Right, that's me cuppa tea finished, back on the job ..................

[Paul Barker]

So what stage are you at is it running OK now?

I am conscerned that you may not have cleaned all the flue ways and ai intake path. Also conscerned that the inspection plates may not b sealed. What I suggest you do is, with boiler turned off, place a smok bomb in the inlet flue duct and watch to see that there is a good flo of smoke back out of the exhaust duct. Simultaneously inspect the seal on the boiler to ensure absolutely no smoke gets out into the room.

Then, assuming you have washed the burner good to remove any lint an clear the holes of the burner including the little flame retensio holes, that the flame picture is good, now you need to check the burne pressure and or gas rate it. If it is working according to the Watso House Plate, that is the burner pressure is set where they suggest an the gas rate comes out right, then you've cracked it.

All this advise is given on the basis that to carry out any of it yo must be a competent person and you aren't doing this for profit

-- Paul Barker

[Dave Plowman (News)]

Well, yes, but it's about as basic a boiler as it gets. Take the top off and you can see clearly inside the terminal. I'd just sort of assumed anyone willing to have a go would then at least have a good look at everything.

I'd agree it would be best to use a proper fitter to do all this, but having gone this far I'd say it worth just doing the job as thoroughly as possible - the chances of getting anyone 'good' in within the next week or so are remote.

So since the boiler's already in a 'dangerous' state, and the OP knows this, a little help on at least how to cleaning it all properly won't go amiss.

[Mike Faithfull]

Well, I have a much cleaner flame now, but it's still a bit smelly. Close inspection shows that the old and disintegrating "mineral rope" (don't know what else to call it!) that should be sealing the front plate of the combustion chamber isn't doing its job. It's only a couple of minutes work to take that plate off and replace the seal, so I shall buy some tomorrow and try it. If that doesn't do the trick, then I think I shall have to call in a pro. Just hope I can find one who has more than one brain cell to go with the CORGI certificate and who is willing to perform a conscientious inspection, honestly consider and suggest alternatives - if there are any - and not simply condemn the existing boiler out of hand as a preliminary to trying to sell me a new one ...

[Dave Plowman (News)]

If you'd read my post on the subject, I said to check the seals. They usually need replacement after being disturbed.

I'm hoping you've had the top inspection plate off for a thorough clean and will replace that seal too?

There is nothing on that boiler that can't be fixed. In some ways I wish there was, as I'd like to be *forced* into replacing it with a more efficient modern one.

However, the near total lack of service costs - compared to the horror stories one reads on here and elsewhere about repair costs on many modern boilers makes me feel like leaving well alone - the saving of perhaps 15% on my gas bill wouldn't pay for a new unit.

[Ed Sirett]

A boiler like this would (if I had not got the opportunity right away to fix it) get an ID notice (see FAQ). A proportion of registered fitters (especially when they work for large companies) would not even consider that it is worth repairing they would simply give you a quote for its replacement and leave it turned off.

It needs a thorough strip down, likely the root cause of the trouble is that the gauze inside the mixing tubes is blocked with fine crap.

With all due politeness if you need to ask about what to do with lumps of soot in boilers then you need to get in outside help.

[Ed Sirett]

It seem quite a few posters have missed the fact that this boiler is a Pott. Kingfisher CF 60.

The CF means Conventional Flue -i.e. air comes in to the room through a vent and the gases leave via a vertical flue pipe.

So a competant service for this model will include spillage tess at the draught diverter and a flue flow test. The latter might be omitted if all was in good order but given the amount of soot everything is in the frame.

[Mike Faithfull]

Point politely made and well taken, Ed! I rather took the brake off my typing hands before the brain was fully in gear - put it down to shock after seeing that great lump of sooty crud hanging there! I think I have resolved the initial problem - apart from some remaining soot in the fins of the heat exchanger which has proved difficult to remove - and the presence of fumes is now most likely due to leakage around a poorly sealed front plate on the combustion chamber. As stated, replacing that seal is a job for tomorrow. If that then fails the "nose test" it will be time to call on somebody who has both the expertise and the necessary tools and equipment to properly diagnose and fix the problem.

[Andrew]

I had exactly the same problem with the same boiler - a Corgi guy came out and gave it a service, but it still burnt with a very yellow flame and smelt, so he condemned it (said I should replace it with a combi as it was impossible to get the parts, and must be about 20 years old...)

It turned out the fins were still sooted. The Corgi had cleaned a lot with a brush and on first inspection the heat exchanger looked clear. However, I spent another hour cleaning it until the fins were completely clear (with a plastic ruler - the soot was too baked on for a brush) - lots more soot came off and then the flame was perfect again.

Clean the fins completely and you may find your problems disappear!

regards, Andrew

[Dave Plowman (News)]

I certainly did. I just saw Kingfisher. ;-(

I'm certainly rather blase about servicing on an RS type - but *not* on a CF model. I had a dear pal damn near killed by 'pro' kitchen fitters boxing in his CF boiler with one of their standard units - which had no ventilation.

However, I'd still start by making sure everything was squeaky clean.

[tarquinlinbin]

There was a technical bulletin issued about a year or more ago relating to Pott Kingfishers and sooting up. The urgent tech bulletin was issued as a result of a fatality as far as i can recall. My info on this is a bit sketchy as my memory is not so good and i cant recall if the bulletin was issued by Potterton or British Gas. It may be that it has sotted due to lack of or incorrect servicing or it may be that the problem falls within the scope of the bulletin and mods are required ??

joe

[John Rumm]

You might have just saved his life except for one tiny detail....

You are replying to a thread that was started at the end of 2004 and already had plenty of sensible answers.

[Andy the Gas]

You are in SERIOUS danger of Corbon Monoxide poisoning. The sooting fumes and flame colour are usualy caused by lack of ventillation o fluing problems. Check that your air vent is not blocked in any wa ...even a heavily dusty one can prevent air from entering. If th boiler is in a cupboard thereshould be vents in the door or wall. CAL IN AN ENGINEER - Could save your life!

-- Andy the Gas