Boiler has been working fine for the few years we have been in this house. Every thing was fine until last weekend when the water pressure into the house dropped right off, hardly a trickle. I suspect the was either works or major leak on the road mains somewhere. Pressure was back to normal the next day. Now we seem to have a problem with the DHW not firing up the boiler. We can get hot water if the heating is on, obviously this is because the heating fired up is heating up the water to. Any suggestions on the possible cause would be appreciated.

Viv, December 2008

Thanks for that Dave.
You mentioned assuming water pressure being ok. The pressure on the cold is really good but on the hot not so, and since the pressure drop it is now slightly worse than before, infact rather poor i would say. Could this be a possible reason or stick with the DHW flow switch. The pump seems fine if that helps.

Appreciate your help on this!

Viv, December 2008

Domestic Hot water flow switch by the sound of things - assuming that the hot water pressure is now ok

gasmandave, December 2008