Valliant boiler pressure above range

[AlfredoMoon]

Just moved into a new house and there’s a Valliant Ecotec boiler that I think has a problem.

Pressure is climbing and sits around 3.6bar when boiler is on standby. (Higher when heating kicks in). There overflow at the rear wall is continually dripping.

I bled radiators and even emptied the system and refilled only to 0.5bar. Pressure then just climbs through to the high pressure 3.6-4.0 again.

Is this potentially a faulty filling loop/valve that’s continually feeding more water/pressure into the system. I noticed some staining on kitchen ceiling from previous drip. Wondering if this sort of pressure build up can force water out of pipes if the overflow can’t cope?

 

[Stuckinarut]

Yes can be a faulty filling loop valve or pinholed plate heat exchanger but likely the former. If it’s doing it with the heating on then sound so like you have an expansion related issue and a new prv, so best engage with a gas safe registered engineer