my glowworm micron 50ff boiler is constantly lighting and switching itself off after a few seconds and seconds later relights, both stats(water and heating are in demand at the time )any ideas as to what the problem could be? boiler acts the same when either water or heating stat is in demand. it also stays off when in demand!! sounds a complex problem to me can anybody help please, sat listening to it fire up and shutdown as i type this.

tony, February 2008

could be your thermistor try as cheaper than pcb

chris( plumb), February 2009

hi tony,its the air pressure switch inside the boiler.its what they call "hunting",the boiler starts-stops going through this cycle.common fault on the micron range,hope this helps

grant, February 2008