no central heating but DV actuator is operational

[R3su]

Hi all,

I’ve recently moved house and inherited a Worcester green star heat slave 12/18 with a Honeywell wireless thermostat.

A day or two ago we lost central heating. The hot water works fine as the boiler fires up.
However there is no heat in the rads throughout the house.

I bled the rads thinking there was possibly an air lock.
And set the stat at 25c.
I’ve re-paired the stat and also bypassed it by jumping terminals LR and LS in the boiler.
The diverted valve actuator is a Drayton 27900 and appears to move when the stat is over ridden but central heating still doesn’t work nor does the boiler fire up.

Is it sensible to assume the valve is shot or are there other things I should check first?

Many thanks

 

[jeff the gasman]

End switch failed in actuator. New head will sort it. With valve open check for 230v on orange wire.

 

[R3su]

Hi Jeff
Thanks for the reply. By end switch do you mean the micro switch inside the actuator under the motor?

 

[jeff the gasman]

Hi Jeff
Thanks for the reply. By end switch do you mean the micro switch inside the actuator under the motor?

Yes mate. Grey supplies the switch and orange is the output.

 

[R3su]

Perfect diagnosis Jeff! Thank you.
Removed the actuator to find that the valve had a small weep where it connects to the actuator.
That moisture had corroded the micro switch which is now shot.

Also found that one of the springs had broken from it mount so I think it’s going have to be a full diverter valve and actuator swop.

 

[oilhead]

If there is a weep from the valve, then there is no alternative to changing the complete valve.

 

[R3su]

Me again!
Thanks oilhead. Replaced the valve this morning and the actuator.
Just waiting for the system to heat up again.

One thing we needed to do is drain down the tank at the base of boiler. We re-pressurised the system and bled the rads bit I’m hearing water gurgles / bubbles within the boiler.
Is there a bleed valve I need to use to ensure no air remains in the system?

 

[R3su]

Well, I’m now in a worse state than I was before.
Boiler now not firing at all.
Somethings running as there’s a hum but it doesn’t plume or anything.
Also note that the actuator doesn’t move.

Bled the system via the two valves on top and also bled the pump.

 

[jeff the gasman]

Probably overheated. I’m going to the pub will check in tomorrow if you’ve not sorted it by then.
Post the boiler manual up, there’s an overheat stat somewhere.

 

[R3su]

Jeff, Please PM me your PayPal details (if you have paypal) and I’ll send you over a small gesture of thanks. You were right again!

 

[jeff the gasman]

Jeff, Please PM me your PayPal details (if you have paypal) and I’ll send you over a small gesture of thanks. You were right again!

Glad to help. Hit the thanks button. Means a lot to regulars.