Central Heating - HW works, heating doesn't?

[mikeshe0]

I changed over the syncro motor on the mid position valve to one I knew worked and it made no difference. I suspect it may be the printed circuit board on the mpv.

If i'm wrong can someone tell me what it could be or where I should be looking, if I may be correct can you confirm that so I can get a new mpv.

The boiler is a gloworm Ultimate.

Thanks.

 

[mikeshe0]

I've pushed the lever on the side of the mpv and I now have heat going the hw and the heating together so it can stay like that until the warmer weather then I'll get a new mpv fitted.

 

[45yearsagasman]

OK

 

[mikeshe0]

I've just read that if you push the lever to the right and push it in (which I have) it locks in the open position, it should automatically release when the valve is powered. Mine doesn't release so what does that mean, could it be the actuator?

Anything's got to be better than replacing the whole valve!

 

[MANDATE]

Sounds like one of two things to me.
Micro switch 1 in valve faulty, preventing power to motor to drive valve over the firstl half of the range.

The actuator head on most valves can be replaced without removing the actual valve.
The PCB is used for retaining the valve in mid position only,so can't see that being the problem.

 

[mikeshe0]

I've got the ACL Lifestyle 679H340-3OLO which I believe is too old to simply replace the actuator and needs a complete valve replacement.

I'm going to try a new synchron motor and see if that works, if not I'll leave it locked manually until warmer weather arrives. My valve is pretty low down on the system so it's almost a complete drain down to change.

 

[MANDATE]

Leaving it locked in mid position won't achieve much.
It will give you CH and hw together, but for how long?
As soon as HW is satisfied the boiler will stop because it was lit via the cylinder stat.
The valve then moves to CH and the boiler re lit.If the valve does not move from mid position the boiler can not be re lit cause power can't come from the valve, cause the second micro switch has not been triggered.
Another aspect is the roomstat.It's the room stat that supplies power to the valves white wire.
If the room stat is faulty and power is not getting to the valve, then it can't move from HW position,other than by the hand lever so its worth checking the room stat