Help with Ideal C28 boiler please?
Discussion
We've been having some issues with our Ideal C28 boiler.
It began as follows:
The thermostat would call for heat, the boiler would fire up perhaps 3 times and then go into lockout.
What would also happen, was the thermostat would call for heat, the boiler would attempt to fire but nothing would happen.
Running the hot water tap would cause the boiler to fire, and then the heating would work normally...
In between all this, sometimes when the boiler fired, there would be an almighty 'woomf' presumably as the heating chamber has filled with excess gas.
Now - this boiler is under a maintenance contract, and an engineer called, fiddled with it for a while and proclaimed that the gas pressure was incorrect (I don't remember if too high or too low).
He left presuming he had repaired it, however within hours it started doing the same thing.
Fast forward to today, and another engineer came and looked at it, also stated that the gas pressure was wrong (apparently the previous engineer had set the pressure for a C24, not C28...) and he adjusted it to the correct pressure.
Said engineer also says that the diverter valve is faulty, as he says that the feed pipe to the radiators is getting warm when the hot tap is running - however after the heating had been off for a few hours today, I tested that theory myself (by feeling the pipe while running hot water) and I didn't notice any heat in the radiator feed pipe.
Other symptoms:
The hot water doesn't seem to regulate properly, in that it gets steaming hot, and then will suddenly cool right down - and - while this is happening, you can hear the boiler cut out for a few seconds and then fire up again. It's almost as if the heating chamber (not sure what you call it) is not adjusting the amount of heat supplied to the heat exchanger.
Additionally, it can sometimes do this same thing while the CH is running - the boiler will be running, then shuts down (pump carries on running) and then the boiler will fire up again a few seconds later. (same as for the hot water above).
Now, I'm not a heating engineer, and I will hold my hands up and say I know very little about boilers - but I'm not sure if the engineer's diagnosis' are correct.
And ideas anyone?
TIA!
It began as follows:
The thermostat would call for heat, the boiler would fire up perhaps 3 times and then go into lockout.
What would also happen, was the thermostat would call for heat, the boiler would attempt to fire but nothing would happen.
Running the hot water tap would cause the boiler to fire, and then the heating would work normally...
In between all this, sometimes when the boiler fired, there would be an almighty 'woomf' presumably as the heating chamber has filled with excess gas.
Now - this boiler is under a maintenance contract, and an engineer called, fiddled with it for a while and proclaimed that the gas pressure was incorrect (I don't remember if too high or too low).
He left presuming he had repaired it, however within hours it started doing the same thing.
Fast forward to today, and another engineer came and looked at it, also stated that the gas pressure was wrong (apparently the previous engineer had set the pressure for a C24, not C28...) and he adjusted it to the correct pressure.
Said engineer also says that the diverter valve is faulty, as he says that the feed pipe to the radiators is getting warm when the hot tap is running - however after the heating had been off for a few hours today, I tested that theory myself (by feeling the pipe while running hot water) and I didn't notice any heat in the radiator feed pipe.
Other symptoms:
The hot water doesn't seem to regulate properly, in that it gets steaming hot, and then will suddenly cool right down - and - while this is happening, you can hear the boiler cut out for a few seconds and then fire up again. It's almost as if the heating chamber (not sure what you call it) is not adjusting the amount of heat supplied to the heat exchanger.
Additionally, it can sometimes do this same thing while the CH is running - the boiler will be running, then shuts down (pump carries on running) and then the boiler will fire up again a few seconds later. (same as for the hot water above).
Now, I'm not a heating engineer, and I will hold my hands up and say I know very little about boilers - but I'm not sure if the engineer's diagnosis' are correct.
And ideas anyone?
TIA!
280E said:
How old is the boiler, and are you in a hard water area?
Have you tried measuring the hot water flow rate in litres/minute? There is a filter on the cold water inlet side, which might be clogged.
The boiler is 13 years old, and we're in a soft water area.Have you tried measuring the hot water flow rate in litres/minute? There is a filter on the cold water inlet side, which might be clogged.
There are no issues with the hot water flow.
This morning, the heating was running, but then the boiler just stopped, even though the thermostat was calling for heat.
I noticed it was unusually hot in the vicinity of the boiler which is in a fairly open space under the stairs.
My guess is this confirms the engineer's diagnosis of a stuck diverter valve, as I suspect the boiling was trying to push to water around the radiators, but was unable to do so as the diverter valve was switched (I presume) to hot water?
As soon as I ran the hot tap, the boiler fired up and hot water flowed as per usual - however it still gets very hot, then cool, then very hot...
It does sound like a diverter valve. Just an FYI: "Someone" has been battling problems with this boiler over Christmas only to eventually put a multimeter across it and discover that the wiring from the thermostat was loose and while it was demanding heat, it wasn't creating continuity at the boiler. It's a 3 minute job that could save significant head scratching 
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