Boiler running for no reason

[tony p]

I have a boiler that keeps switching on and off even though there is no demand.
Both the hot water and the CH are timed off (Tempus 6 programmer shows no lights) but the boiler insists on coming on all the time. The temp indicator is permanently around 85 deg- drops to around 75ish and then the boiler starts runs and then shuts down.
This leaves continuously sounds like the water is simmering in the pipes between the valve and the boiler. there is a small (15mm)run around before the two valves.

The system has 2 valves - not a 3 way.

Any ideas please as my gas bill is enormous!!!!

 

[gas4you]

Sounds like one of the microswitches in a valve head has stuck on.

You need to test for 240V at each of the orange wires. The one with 240V is the faulty one.

 

[bengasman]

If the values are in fahrenheit, it must be a very old set. Might as well renew the components if it gives you problems

 

[tony p]

Not sure if its the same problem or is my wiring totally to pot?

I've noticed that the pump is also running even with no demand (timed off) and when the boiler is not on.

If i put the programmer to 'off' (CH & HW) the boiler and pump still run.

If i turn off the boiler (greenstar HE) on its facia plate the pump and boiler do turn off OK.

Many Thanks