mid-position valve not working

Postby tiermacgirl » Thu Jan 08, 2009 10:14 am

I hope someone can help. Not had a hot shower since this started.

Away for a week when it was v v cold but to prevent freeze-related leaks the system auto switches on when the tank goes below a certain temperature so thought would be fine when I got back.

Rads work fine but if I switch on hot water the valve won't go to mid position as it should. If I switch off power to boiler it goes to hotwater only position, but I need a way to get it to do that with boiler operating! The manual control seems to have a mind of its own too, I am not convinced it works at all.

On top of that the auto protection is keeping the central heating going permanently at the moment so I can't test what happens from cold because it can't get cold!

Experts out there? or even someone that has fixed this before? Please!
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Simply Build It

Postby plumbbob » Thu Jan 08, 2009 5:33 pm

Find the frost stat and turn it down as low as it will go. This stat is overriding all other controls and forcing the 3PV full on to heating only.

If the boiler is fitted in an unheated area, then the frost stat will stay on until the weather improves.

Lag exposed heating pipes, move the stat as close as poss to the boiler so the residual heat will switch it off, and turn it down to zero.
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Postby tiermacgirl » Thu Jan 08, 2009 11:15 pm

thanks: I started thinking that if i could get the thing to cool down it might work. Turned off electricity completely for a while, that worked! I did have to be patient though.

There's a lot to fix with my heating anyway so I am getting someone round soon to advise how to improve the system.

Most grateful and decidedly less odorous now.
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Postby Steve the gas » Fri Jan 09, 2009 6:19 am

Also lock the slider on the MV to manual position, to see if MV at fault.
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Postby tiermacgirl » Fri Jan 09, 2009 11:13 am

Thanks Steve the guy coming round today will check the valve assembly to see if there isn't something wrong with it anyway.
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Postby TheDoctor5 » Thu Jan 29, 2009 1:26 pm

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