Central heating valve seized- how to unseize?

[hiasakite]

The valve that opens to let the hot water into my central heating circuit has seized, resulting lovely hot water from taps and heated towel rail in my bathroom (it runs from the hot water circuit)- but stone cold radiators.

I'm pretty sure its the valve that lets water into the ciruit thats stuck as its no opening on the themostat, and when I try to manually open it (there's lever you can pull to do thsi) its just stuck fast..

Any thoughts how to open it as the house is getting a tad chilly and plumber isn't coming till Friday, and I'm told we've a coldsnap on the way...

Half tempted to put a wrench on it and get some leverage but if I broke something I could do more damage with water spraying everywhere...

Valve is a made by Honeywell (one of these www.grantandstone.co.uk/heating-controls/V4043.htm )

Appreciate your thoughts..

[Parrot of Doom]

Is there any voltage on the motor?

[bimsb6]

take the steel cover off (should be held on with 2 self tappers ) remove motor and turn valve with pliers GENTLY !
move back and forth to free it up if this is problem and reassemble .chances are is is the motor that is shot ,if i remember correctly they are 20 quid ish .

[hiasakite]

Haven't tested it- to be honest not sure I fancy testing what could potentialy be a 240V supply-

If I could get the manual overide leaver to move and manualy open the valve it wouldn't be a problem- I could manually open it until it gets replaced on Friday.

[hiasakite]

bimsb6 said:

take the steel cover off (should be held on with 2 self tappers ) remove motor and turn valve with pliers GENTLY !
move back and forth to free it up if this is problem and reassemble .chances are is is the motor that is shot ,if i remember correctly they are 20 quid ish .

I'm guessing I need to 'dewire' it from the mains supply to do this?- I've had the cover off so I'l take a look if this looks doable without disconnecting wire.. have found aadobe Pdf instruction manual off the web..

[bd]

If you have WD40 available spray this on the valve before using pliers; seems to loosen up the valve. Or did in my heating system; kept me going for a couple of years.

[bimsb6]

hiasakite said:

bimsb6 said:

take the steel cover off (should be held on with 2 self tappers ) remove motor and turn valve with pliers GENTLY !
move back and forth to free it up if this is problem and reassemble .chances are is is the motor that is shot ,if i remember correctly they are 20 quid ish .

I'm guessing I need to 'dewire' it from the mains supply to do this?- I've had the cover off so I'l take a look if this looks doable without disconnecting wire.. have found aadobe Pdf instruction manual off the web..

no they just pull off ,if you are worried pull the fuse before playing with it .i did mine live .although i did kill the mains before i changed the motor .

Edited by bimsb6 on Sunday 21st January 19:13

[ferg]

bimsb6 said:

no they just pull off

Two brass screws, one either side so long as it's a relatively recent one.

[dilbert]

Turn the power to the heating system off. There should be a fused switch somewhere near the boiler.

Lift the cover off the motor and remove the mechanism. You may find that the valve is fine, but the mechanism has locked up. This is common when the mechanism wears. The spring inside is powerful, and it is possible for the quadrant to become siezed, because of the worn bearings (such as they are).

If you can leave the motor off, and get the valve open, then you'll probably still get heat from the rads when the hot water is demanding. Tape up the loose motor head, to make it safe, and get a new valve and head to fit.

HTH.

[bimsb6]

ferg said:

bimsb6 said:

no they just pull off

Two brass screws, one either side so long as it's a relatively recent one.

sorry, you are quite correct it's been a while since i did mine