Vokera Flowmatic 20-80 RS - No CH but HW ok

[neily74]

Hi

Can anyone point me in the right direction.
My boiler doesn't seem to fire up with demand for CH,but it does with demand for HW and once the boiler is on an the demand for HW is gone then the CH comes on.

What part creates the demand for the CH to come on?

Thanks in advance

Paul

 

[Agile]

This kind of problem is usually caused by the system flow switch not operating reliably.

Is the diverter valve pin fully retracting after a DHW demand?

Tony

 

[neily74]

hi agile thanks for the reply

the diverter pin fully retracts once the demand for HW has been removed.

is there anything else i can check?

cheers

Paul

 

[Agile]

Whats the system flow switch when Ch is demanded on its own in the situation when the boiler does not fire up!

Tony

 

[neily74]

the system flow switch is open (the pin is fully retracted) when there is only a demand for CH .

could the CH thermostat be faulty? if so is there any way of isolating it?

thanks again for responses

Paul