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Boiler help
ady8077 - 4/10/05 at 07:10 PM

Hi all

Any boiler bofins?

Had a look at mates boiler last week, its a fan flue conventional, pump and fan run but it doesn't ignite

Had a look at the control box and there are 4 led's, mains ok, stat ok, fan proved, and ignition, only the first 2 were lit

So as the fan was running i had a look at the fan pressure switch, hadn't switched, gave it a gentle tap and switch made and boiler fired, ordered new switch

Fitted new switch today, still only first 2 leds on, taped switch nothing happened

The fan seems to be running ok, but doesn't seem to be sucking the switch hard enough, do the insides wear out?

I'm reluctant to tell him to buy a new fan as the switch cost £50 and hasn't fixed it

Adrian

Deckman001 - 4/10/05 at 07:12 PM

Try u2u'ing GasGasGas ,, guess why he's called that

Jason

JoelP - 4/10/05 at 07:19 PM

quote:
Originally posted by Deckman001
Try u2u'ing GasGasGas ,, guess why he's called that

Jason


flatulence?

Deckman001 - 4/10/05 at 07:21 PM

that is one of them !!

Jason

BKLOCO - 4/10/05 at 07:24 PM

Check the flue for obstructions

mark chandler - 4/10/05 at 07:25 PM

Mine played around like that, there was a plastic tube going from a switch the tube was blocked so the air pressure from the fan was not closing the contacts.

While I was about it pulled everthing apart, blew through all pipes, hoovered out the elements and put it back together. Disco ! 5 years ago now..

Good luck

fatfranky - 4/10/05 at 07:37 PM

Similar thing happenned to me a couple of months ago, boiler simply would not ignite (combi) turned on tap piezo thingy would tick tick tick then reset would pop out.

3 days of cold showers later and telephone quotes of approx £1000 for a new boiler, I went to turn fire on, and found that it wouldn't light either nor cooker for that matter.

Turned out Transco had installed new gas main couple of years ago and had transferred everyone except me onto it, and had then turned off old main that week.

Might sound stupid but ensure gas is reaching boiler

Markp - 4/10/05 at 09:03 PM

first of all what boiler is it? Sounds daft but it could be a couple of things depending on what you got. Give me the make / model or better still the GC no. if it is a fan flued boiler it will start with 41***** this can be found on the data badge somewhere on the boiler if not as much details as poss.

Sounds like an easy fault to sort.

Markp - 4/10/05 at 09:09 PM

ps. If the fan is running then the problem normally isn't the fan. it could be the fan venturi (most run around 2-3mbar pressure for the switch to make) as long as the fan is running well. try swapping the tubes over on the air pressure switch (you MIGHT have fitted them the wrong way around)

As I said, give some more details and I'll have another go if that doesn't work.

cheers Mark

ady8077 - 4/10/05 at 09:10 PM

Hi

Thanks for the suggestions

I'll get him to check the flue and run the hoover around it

I'll get the model number, all i can remember is its a honeywell

Adrian

Hellfire - 4/10/05 at 11:42 PM

There was a problem on mine a few months ago - I've dumped it since... it was the water pressure sensor. When the pressure dropped the actuator opened making the switch and igniting the gas. The diaphram in the actuator had corroded (again) twice it's happened in 5 years. Dumped it and got a BOSCH... beautiful product and only £400....

JAG - 5/10/05 at 08:09 AM

quote:

it could be the fan venturi


That is exactly what was wrong with mine. The venture is in the exhaust from the boiler and can get whiskered up with 'products of combustion' basically ash/bits in the exhaust gas.

The venturi is used to amplify the pressure in the exhaust (caused by the fan running) so that it switches the pressure switch. If the venturi gets blocked the pressure switch won't switch and the boiler won't light or will trip out soon after lighting.

The original venturi was steel and apparently prone to this problem. My boiler maker supplies a replacement part in a special plastic that stops the whiskering up.

Got this fitted and the problem has gone away.

ady8077 - 6/10/05 at 05:00 PM

Hi guys

fixed it

Took fan apart and where the pipes from the press switch went in there was a green crystal substance blocking the holes

Thanks for the help

Adrian