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ICI caldai solar 80 erratic heating problem

Postby gloryhornet » Wed Feb 20, 2008 9:00 pm

Hi there I have a problem with my 11 year old Combi Boiler, been ok for 10 years, now the hot water is good but heating is not working properly. I have had 4 visits from BG engineer (homecare plan) and still not sorted.

It started with the central heating working ok but, a lot of clicking noises(microswitches) coming from it before it would fire up.

BG engineer came out last Thursday said it was a PCB fault and returned Friday and fitted a new PCB he noticed a leak and said the divertor valve needed replacing. This is where our problems start.

After he left the boiler wouldn't work properly, It would fire up then there would be a whooshing sound coming from it, the temp gauge would go up to 80oc and the boiler would cut out, the radiators are warm on the top but cold on the bottom radiators would then go cold no heating.

Engineer returned Monday we explained the problems with the boiler, he said the valve should sort it, fitted it (3 hours), boiler not firing up properly, said the system was probably sludged up and would

need flushing (not covered by plan £500), but would return Tuesday with a new pump to see if it is that. Called up a plumber friend who came over we removed 2 radiators (first and last in system) and emptied and flushed them out, the water was dirty, he said there was no sludge in system. Replaced radiators filled one with 4 litres of Fernox repressurised system, but no joy.

Engineer returned Tuesday, told him want we had done, showed him the water from rads he said system should be sludge free. Fitted pump, fired up the boiler, worked perfect, he said the radiators needed balancing, he done that and left. Heating worked perfect for about 4 hours until the timers switched heating off. when the timers restarted the boiler, the same old problem returned. Rang up BG, the engineer is returning Thursday. They said system needs flushing.

I think it is an electrical problem, if I turn the boiler off for 5 mins and restart it it is ok for about 5 mins and works, or if I leave the thermostat on maximum, it stays firing (same whooshing sound though but not cutting out).

What do you good people think? Is it time for a new Boiler? (expensive), or a system flush? or is the new PCB knackered?

ps sorry about the long post this problem is stressing me out and money is tight..
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Postby ericmark » Fri Feb 22, 2008 2:10 am

You say the problem started after he replaced a valve. There are two types of three port valves change over and mid position could he have fitted the wrong one? Y system with mid position I can find wiring for valve but two position with switch I can't find the diagram so can't be sure what would happen with wrong valve he may not have even realized as two position is rare and not something one would auto look for.

Postby gloryhornet » Sat Mar 01, 2008 3:45 pm

Hi there

Thanks for the reply, we had a new engineer out and it turned out to be the thermostat on the heat exchanger, He had to replace the whole heat exchanger just for a thermostat... :?

British gas have nearly replaced all of the parts in our boiler, so I hope to get a few more years out of it...
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