One radiator zone not heating

[resjud]

Hi there

I have a system boiler heating 3 radiator zones, 1 wet underfloor zone and 1 unvented cylinder zone. The zones are each controlled by separate zone valves wired into a central wiring centre, with separate wireless thermostats for each zone linked to the wiring centre.

One radiator zone (with 3 radiators on it) is not heating up. The pipe leading into the relevant zone valve is hot, and when I activate that zone from the relevant thermostat then the pipe on the other side of the valve also becomes hot.

I have tried releasing any air from the 3 radiators affected, but there does not seem to be any in there. I'm guessing that there might be an airlock somewhere else in that zone but I don't know how to release it.

Any help please? Thanks!

 

[ShaunCorbs]

Has it worked in the past ?

 

[SimonG]

Any pictures of the valve set up?

How far along after the 2 port does the pipe get hot?

Radiator valves all wide open?

 

[resjud]

Thanks both, the zone has worked in the past, yes.
Photo of 3 of the 5 valves is attached - only photo I have to hand at the moment which is (obviously) pre wiring in of the boiler and valves. As you can see, there isn't much scope to see how far after the valve the pipe gets hot, because it disappears into the floor.
Radiator valves are all wide open, yes.

 

[ShaunCorbs]

Close all / don't turn the other zones on but the closest rad to the boiler that doesn't work

Now open the zone that doesn't work

Leave it for 10-15 mins is it warm

If not try and air it does any come out ?

 

[resjud]

Thanks, will try this evening when I get home and update.

 

[resjud]

So I tried that and nothing heated up and there was no air in either radiator.

I have looked a little further at the zone valve. When all the other zones are turned on, then off, the valve makes a whirring noise when the zone is turned off and the valve closes. With this valve there is no whirring noise when the zone is turned off.

All the valves still call for heat when they are opened.

Any ideas?

Thanks again.

 

[SimonG]

Heads goosed.

 

[ShaunCorbs]

there should be a lever on the side to manually open the zone open it / move the lever

 

[resjud]

Is a head failure normal after 2 years?

With the valve set to open manually and the thermostat turned on, that zone doesn’t seem to call for heat as the boiler doesn’t fire up. But the wiring centre “boiler” light lights up, in the same way that it does when any of the functioning zones are activated.