Motorized Valve Nightmare

[Mike Annable]

Hi,

I have a heating problem such that the pump runs continuously. At firs I thought the problem was the controller, but on further investigatio it is the 2 port motorized valve (HW).

Either the valve is stuck open and/or the switched output i permanantly on. The problem I have is that whoever installed thi system several years ago and before we moved here installed the valv hard up against the tank (or rather the tank up against the valve), s I cannot remove the cover.

As a temporary measure I have linked the pump supply to the valve inpu from the tank stat - i.e. the pump won't switch on unless the heating i on and the water in the tank is below the set point (or the CH system i switched on).

I appreciate that this removes the independence of the two circuits (H can be on alone, but if CH is on HW will also be on regardless).

I know this is not ideal, but how can I remove / repair the syste without removing the tank??

Any help would be greatly appreciated!

Cheers,

Mik

-- Mike Annable

[The Natural Philosopher]

Well time to sort that properly then

Nasty. Burn the stat out that will.

Use a pipe cutter to remove the valve and the pipe and relocate it somewhere more convenient, and fit a new one.

It sounds drastic, but actually you only have to drain down the primary circuit, and solder a couple of joints and some bits of pipe..

[Jim Alexander]

Rotate the valve +90 or -90 deg if there is room and the edge of the cover will clear the tank. How? Drain, or at least depressurise the primary if you are not confident at slackening off just enough. Slacken off and rotate the valve. Tighten up. And lets see a pic please.

Jim A

[Mike Annable]

Thanks to you both.

The heating system is actually at my Mother's house, so I will tak another look when I visit tomorrow, and will post a pic too. Fro memory I don't think there is space to rotate the valve, but I wil check. I guess it may be a drain, cut and relocate job.....

Don't get why my temporary mod would burn out the stat????

Cheers,

Mik

-- Mike Annable

[Ed Sirett]

A picture would be a worth a thousand words. Someone here will have met the situation before.

[Dave Liquorice]

Very unlikely. Stats are generally rated at 3A resistive 1A inductive. 1A is 230W. A pump is only a 100 or so, the boiler gas valve maybe 10. Well within the inductive rating. Even if it's a oil boiler (or one of these nasty modern power vented gas jobbies) you'll still be hard pushed to exceed the rating by a significant amount.

[Mike Annable]

Thanks to everyone for their comments. Picture attached.

Wall close up to back of valve, and tank up to the front.....

+------------------------------------------------------------------- |Filename: Photo-0025.jpg |Download:

[Jim Alexander]

If only if it had been a Honeywell I think it would have rotated even that close to the wall. Plus a Honeywell only needs 3mm to get the cover off.

Possibly pipe replacement may be needed. Think about using Hep2O which gives you a bit of "give" and also allows rotation. I have 3 diverters supported by Hep2O and pipe clips with no real problem in 10 years.

Jim A

[Dave Liquorice]

I don't recognise it at all, still that's not important.

How far from the valve are the pipes supported? I suspect if you dug out the plaster behind the central bulge so that the nuts actually touched the wall it might just rotate after slackening the nuts. Beware of leaks but finger tight or even a slightest nip with a spanner will stop the worst and still allow rotation.