the water pressure is fine but it does not seem enough to push the micro switch far enough for it to ignite the boiler,
plz help.

tessa beasley, July 2007

when mine did that it was the heat exchanger

laura peil, December 2008

I would probably say the Hot Water Diaphragm has perished/pin-holed. The water that should push the plunger all the way out is getting through to the wrong side. Also check the condition around the plunger hole for signs of leaks which could be restricting the movement. The diaphragms are a common part to replace and are very cheap. Hope this has helped

Mikey, July 2007