My Ravenheat CSI85A boiler fires up for a few seconds then shuts off and goes through the process of firing up again and repeats up to around 8times before finally working. Once it is up and running it works ok until it is switched off. The starting and stopping is done manually not on the timer. The domestic hot water is much the same process but doesn't take so long again once running is ok. Has anyone got any idea what is wrong.

Telfordman, November 2010