hot water great but no heat to radiators HEATSLAVE 20-25

[clyde plumbers]

Hi
I am currently working on a worcster heatslave oil combi 20-25

The boiler is giving hot water but when I select for heating it gives nothing ,should I try pump or diverter valve head first
kind regards
mark

 

[PhoenixServices]

Take the head off the diverter and move it manually to heating position then fire it up on hot water to check it goes round and past then you know it's not the pump or the body.

 

[SimonG]

Room stat?

 

[clyde plumbers]

Ok thanks guys

 

[Bunker]

If the diverter is the metal 3 port valve style do as Phoenix says.
If its the plastic box version, then its more likely to be the room stat or programmer as that one rarely gets stuck on HW only.

 

[clyde plumbers]

I have changed the metal Honeywell head on diverter valve and boiler is now working again , thanks guys

 

[Roger Welton]

Flow switch sticking?