When the power is switched on with the thermostat calling for heat, the fan immediately comes on but the boiler does not go through the start up sequence, basically nothing happens. In hot water only mode when a tap is opened again no start up. Could it be the air pressure switch or the ignition module? There is sufficient water pressure in the system ie just over 1 Bar.

David Marshall, April 2007

How do I get the water pressure to raise?

Jonny, April 2012

if it does not go into the ignition stage it is more than likely the air pressure switch........contact normally open..check for correct operation with multi meter set on continuity..ta

ged.odonnell@btinternet.com, April 2007