I've just had a new central heating system fitted including a new ideal vogue c32 combo boiler to replace the old immersion tank and storage heaters that were in the property before, i fitted a new bathroom suite and has been working fine with all this for a good 2/3 months now but just noticed last night that the temperature of the hot water seems to rise as normal to the temperature required and then will just cut out and it will run cold and then do the same thing again and again?? Any solutions? Is happening when I try all taps and shower will run hot and then go cold then hot again..
Was the original system and pipework old? Was it dirty? Was it flushed out well before the combi was installed? Does it have a magnetic filter on the return pipe before the boiler? Have you checked it? Is it dirty? Could be a few things - including a sludged-up P2P exchanger. This causes the boiler to trip out as it cannot shift the heat fast enough to the DHW due to a partially blocked P2P exchanger. Call out the installer - it's surely under warranty?
DA how is a two month old system going to have enough sludge in it to affect a plate to plate? OP like DA says get the installer back to have a look and probably the manufacturers under a warranty call out.
Have got engineer coming from ideal thur just wondered if anybody had an idea of what maybe the problem seeing as the system is so new...