The boiler has a room thermostat connected to it but when you set the room thermostat to the temperature needed. After a while the thermostat switches off but it does not come back on when the temperature off the room drops. The thermostat has been checked and is working. Therefore we assume it is something wrong with the boiler. Can you help!!!!!!

Mark, March 2008

weres the micro switch

ty, March 2013

A have a noise when the heater is starting to warm up , and the pressure increases and cuts out.

Tyrone, March 2013

silverstar LS 80 T combi...hot water only works when heating is on...could it be diverter valve diaphragm?

Ricardo 52, March 2010

the mains powers up the thermostat
the thermostat powers up heating valve
Heating valve powers up the boiler to heat the room


If Thermostat OK and powering up heating valve
Heating valve not OK and is not powering up Boiler.(Possibly stuck microswitch)

(same applies to combi boilers with integral three port valve)

Big Steve, March 2008