Any ideas please on a vaillant combi condensing boiler ecomax 8242/2e? The pressure rises to 3 bar when the central heating kicks in. Then water comes out of the pressure relief valve and the boiler has to be topped up (got so bad it was every day) Now we are £200 poorer after engineer fitted new relief valve and we still have water leaking outside on the flat roof and when the central heating kicks in the needle creeps up to 3 bar within about 10 minutes and water passes through the PRV. cheers.