Heating keeps coming when boiler is switched on

[yellowfish]

Hi,

Model - Biasi 24s GC - 74 970 06

Been working fine, all of a sudden the central heating comes on automatically. A friend said it's likely the divertor Value. Should I get this replaced or just the Membranes in the Value?

Thanks for your help!

 

[kevplumb]

all of a sudden the central heating comes on automatically

when you run the water or at random

 

[Agile]

The system water is dirty and has caused the right hand diverter valve gland to leak water into the DHW flow switch.

The water needs to be flushed out and then the gland and switch have to be changed. The operating pin has to be replaced or properly cleaned otherwise the problem will reoccur.

As the gas valve has to be removed to gain access, this is a job for a CORGI engineeer.

Tony Glazier

 

[yellowfish]

As I switch on the boiler it starts the heating, once the heating gets hot it stops. (assume it cuts off once it reaches a certain temp??)

Thanks for all your help!

 

[kevplumb]

does not mention having to remove the gas valve here

 

[Agile]

Thats quite true Kev and its because the manual is only describing removing the switch. You can just about do that in situ using forceps to take off the clip if you have patience and an inspection mirror.

To remove the gland the gas valve has to be removed.

In practice when the gland has been leaking the clip for the switch is usually so rusted it cannot be taken off anyway.

The manuals seem to assume the system was power flushed and the gland will never leak. The real world is different!

Tony Glazier