Pump constantly on, what could be wrong?

[Talkingbollox]

if you turn the power off to ya central heating at the fuse spur does the newer valve (the 1 with no resistance on the lever) spring back?

I have turned the power off to the system (as it's the only way to stop the pump) and the valve on the left has no resistance whereas the valve on the right springs back.

 

[Agile]

Sounds like the no resistance valve is jammed on!

 

[gas_man_gaz]

you should have a bit of resistance on the lever, isolate the power remove the head and check the spindle and the head isn't stuck

 

[gas_man_gaz]

even agile is catching on

 

[Talkingbollox]

So the new valve has failed? Do they spring back to the right even when there is no power connected?

Here are the valves (with a dimple). Looks like there is one one screw to undo at the bottom of each valve?

 

[Agile]

Single screw only hold cover on.

Inside are two diagonal screws which hold head onto valve body.

Valve is held in resting position by a spring.

Motor is powered and opens the valve and motor remains powered and stalls.

When motor is depowered the valve should return to the closed under the power of the spring!

Tony

 

[Talkingbollox]

Thanks, Tony.

I looked up youtube and found this guide: http://www.youtube.com/watch?v=Yyn_fBEH90U

I tried to undo the screw but it was having none of it? Bearing in mind I have to attack it from below. What sort of screwdriver should I be using? A phillips or a flat blade?

 

[Agile]

Oh, I need not have bothered to explain if its already on youtube!

You can use a flat blade or a Torx ( I think its a T15 but not checked on that. )

Tony

 

[Talkingbollox]

Valve Head changed.

It was a worn gear/cog, causing slippage and not turning the valve fully as intended.