Ferroli Optima 1001. pump switching off and on frequently.

[pwz9]

I am having a problem with the CH pump on my Ferroli Optima 1001 constantly switching on and off.

The boiler fires up and after a few minuets, the burner goes out and the pump carries on running (for approximately 1minuet), after this time the pump then switches off. About 30 seconds later the burner re-lights and the pump starts up. This cycle then repeats itself regularly until the boiler is turned off. When the boiler is first switched on (from cold) it will run for approximately 10 mins before this cycle is started.

Any help would be appreciated

 

[ChrisR]

The pump's doing what it's told. The problem is that the boiler's going on and off!
Either you have a blockage on the CH, or the sensor could be faulty, or possibly other things.
How's the hot water?

 

[pwz9]

Thanks Chris for your reply.

Everything else is OK with the boiler apart from the pump going off and on. The D.H.W work fine and all the radiators get hot.

My plumber has changed one of the sensors, but this did hot solve the problem.

It has been suggested that there is a problem with VMF7 P.C.B.but I do not want to change it if the fault lies somewhere else.