My boiler is a Worchester 28cdi pressure is increasing up 3 bar by itself ,but is working fine ,even though I have drained the water pressure with release valve ,and even though the boiler is not been used the pressure goes up by itself, I drained it to bring pressure under 1 bar ,but after few minutes it was back up to over 2bars.

Arthur, February 2010

if it's going up WITHOUT the burner ever being on, you most likely have a faulty plate-to-plate heat exchanger. make sure the fill loop key is out, and that there are no old fill loops anywhere on the system

andy, February 2010