Central hearing not being triggered by control panel

[Benillsley]

Hi, I hoping someone may be able to help!
I have the following system:

Worcester 15ri boiler
Drayton RTS1 thermostat
Drayton Lp522 programmer
BGMVSP-23 actuator/ mid position valve

Both the HW and CH have worked fine and independently up until yesterday evening.. Now the HW works fine, turns on as it should and fires up the boiler and I have hot water. However if I turn the HW off and just turn the CH on the boiler doesn’t fire up.

So far I have checked the mid position valve. By default it’s in the M position in the middle, with both the CH and HW on it stays there as I understand it should?
With just HW on it moves to W and I have hot water (and the boiler fires up), with just CH on it stays on M when it should go to H? And as previously mentioned the boiler doesn’t fire up and nor does the pump.
I’ve removed the actuator head and can easily move the valve spindle with my fingers, it only moves about 20 degrees which I’ve read is about right.

I’ve checked the thermostat is working by removing the cover and jumping the live wire to pin 3 ‘call for heat’. This makes no difference so I’m happy the stat is not at fault.

I’m not sure where to turn next? Has the programmer just died over night, it actually stopped working as we were changing the timings for the colder weather but this seems to be a coincidence.

Any advice would be greatly appreciated!
Thanks
Ben

 

[SimonG]

Sounds like programmer, testers out to prove it.

 

[Benillsley]

What’s the best way to test? Remove the programmer and jump a cable from live to HW on?

 

[SimonG]

Need to trace your 240 volts from programmer. Need to know its sending voltage to control head.

 

[Benillsley]

Need to trace your 240 volts from programmer. Need to know its sending voltage to control head.

You’ll have to excuse my ignorance but what/ where is the control head? I’m still learning the terminology!
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I got a bit of my description wrong,
the valve is on H when HW and CH are off on the programmer. With HW turned on it stays on H with HW and CH on it goes to the middle (M) and with just CH on it stays in on M but the boiler Doesn’t run. Does the position valve ‘tell’ the boiler to fire up? Could it be working mechanically but not sending the right signal?

 

[garygvl]

for heating to fire with only ch selected 3 port valve needs 240v on white wire from programmer and room stat and 240v on grey wire from programmer hw off terminal or hw off from cylinder stat

 

[Benillsley]

for heating to fire with only ch selected 3 port valve needs 240v on white wire from programmer and room stat and 240v on grey wire from programmer hw off terminal or hw off from cylinder stat

Great, thanks I’ll get the multimeter out again this evening.

 

[Benillsley]

Here’s my voltage tests from last night

 

[garygvl]

you need a new motorised valve head if as you say valve body is moving freely. thev bg ones are usually drayton but a pic would help
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one thing to check. take the motorised head off and see if it goes to heating position when its not attached to valve body

 

[Benillsley]

I replaced the actuator last night and all is now working as it should. Thanks for the help!