Valve not working correctly

kippy

Hi,
I've a closed oil fired central heating system. The downstairs rads are on an electric valve controlled (I believe) by a thermostat in the sitting room.
This valve has a lever on it labelled "Auto" and "MAN".
The termostat is set to 30 degrees for testing purposes.
When the heating is on the lever moves to Auto however the rads do not head.
I push the lever over to "MAN" and they heat up, however next morning the lever has been moved to Auto again (I do feel some force when I move it to MAN)
I think it's one of these but with a blue cover:
http://www.ambient-instal.ro/en/2-way-threaded-spring-return-with-el-motor/

Any ideas what the problem is with? The termostat? The Valve?
I wouldn't mind of the lever stayed in MAN but its not doing that.


As an aside, is there any good online resource for getting to understand domestic plumbing and how it works?

Cheers

cikearney

that switch you are pulling across the MV is just a manual overide put the for filling and flushing purposes. if it moves across with ease it means the valve is already open and when there is resistance it means that you are manually opening it.

With the heating on remove the acctuator head from the valve and turn it upside down, you should see a slot that will correspond with the bar sticking up from the valve. turn your wall stat down, the slot should movento a horizontal postition and then turn it back up for it to move into a vertical position. If this movement does not take place you need to replace this acctuator or thermostat.

If it does move check the pin that stick out from the valve, on the pate it should show you the position this pin should be in for the valve to be open/closed try spinning it around, there shouldn't be alot of resistance depending on age, if it is very stiff this may also need replacing

kippy

cikearney wrote: »

that switch you are pulling across the MV is just a manual overide put the for filling and flushing purposes. if it moves across with ease it means the valve is already open and when there is resistance it means that you are manually opening it.

With the heating on remove the acctuator head from the valve and turn it upside down, you should see a slot that will correspond with the bar sticking up from the valve. turn your wall stat down, the slot should movento a horizontal postition and then turn it back up for it to move into a vertical position. If this movement does not take place you need to replace this acctuator or thermostat.

If it does move check the pin that stick out from the valve, on the pate it should show you the position this pin should be in for the valve to be open/closed try spinning it around, there shouldn't be alot of resistance depending on age, if it is very stiff this may also need replacing

There is no chance this is a dodgy thermostat?

cikearney

kippy wrote: »

There is no chance this is a dodgy thermostat?

Could well be even if the stat is clicking when turning up and down I've came across two that were still faulty.

You need to see if there is power at the MV by either checking at the wiring centre or the stat itself, the stat will have a live in, which will be live when calling for heat at the clock and a switch live which will should be live when calling for heat from the stat