mid pressure valve

[jayne]

can you please advise me of what the above does, It is situated on the water pipes in my immersion heater cupboard and actually says ACL MID PRESSURE VALVE. The settings read M>W<H and unfortunately these settings seem to have been altered. The little handle underneath has been broken off. I need to know what this valve does, what the settings mean and if they can be manually altered. Thankyou

 

[blueshields]

Does it look like this;

If so, it is a "Mid position valve", not a "Mid Pressure valve"

The "Little Handle" enables you to manually move the valve, usually between DHW and CH or both.

Normally, there are no settings on these valves as they are controlled by timers etc.

Perhaps just an indicator whichs tells you: ?

M = Middle (Both heating and Hot Water).
H = Heating.
W = Hot Water.

 

[jayne]

Sorry put this original text on yours.


Thanks for getting back to me your are right about the type of valve. The setting was originally on M it is no on H. Both water and heating are firing up together when my boiler is on, but since this valve has been altered if I try and put the heating on alone the boiler will not fire up. I have to put the water on as well. Could this be due to the valve being altered. If so how can I correct this with the handle having been broken off.

 

[taydo]

the valve in the picture is electrical it adjusts itself to either water, heating or both if it is not working you will either need to replace the motor inside or the whole valve by the sounds of it eg bits broken you probably need the whole thing.

 

[jayne]

the valve in the picture is electrical it adjusts itself to either water, heating or both if it is not working you will either need to replace the motor inside or the whole valve by the sounds of it eg bits broken you probably need the whole thing.

I just don;t know whether the valve is working or not, as I say both heating and water are running ok when timer is on, if it was broken would heating and water work? Do you know how much the valve costs to replace? would it still work if only the handle adjustment was broken off?
Sorry to hit you with all these questions, just trying to save myself abit of money.

 

[oilman]

Here' some checks you can try. First turn off the mains supply. Then you need to get the box off the top of the valve. The one in blueshields picture has a screw at one end holding the cover on, get this out first. Inside find two screws which hold the electrics part onto the valve body take them out and remove the head from the valve. If yours looks like

see if you can find the rout to getting it's head off.

Once the head is off, you will see a spindle, note its position, and then see that it rotates freely. The best thing to do then is get a new head and replace the old one. How are you on wiring? It's straightforward, but if you don't feel comfortable with it get someone else to do it.

These valve heads fail often, and they are a cheap engineering exercise, so if they fail they nearly always benefit from a head change, sometimes you can get away with a motor change.

Replacements are available online, or from the likes of plumbcentre etc etc.

To answer your questions, the CH and HW would work if the valve was stuck in the mid position. The valve is about £70, but you may be able to get ahead for under £50. It might work with out the handle, but I suspect something failed and the handle was broken trying to fix it.