Ideal Logic Heat 15 Condensing - constant on - Motorised valve stuck?

[stemcgoo]

Hi, I'm hoping for some advice please?

I have an Ideal Logic Heat 15 boiler with water cylinder in an upstairs cupboard. Its a 7 year old system, no issues until this week when E.ON paid a visit to replace my Electricity Smart Meter and so turned off everything briefly (mentioning as can only think this has been the only issue/intervention with the central heating recently).

My Danfoss thermostats are set on a program for periodic temperature improvements through the day, but basically below 20 degC. Anyway, noticed today that CH is constantly on and house very warm. I've switched the thermostats to OFF for hot water and CH, but my boiler is still heating - it can briefly switch off, but pretty soon back on, and my radiators are getting very warm.

I've tried to read up on websites and it seems as though one fairly common recommendation is "motorised valve is stuck". I've checked my water cylinder, and I think I have 3 such 2-port motorised valves. How would I know which if any is faulty or stuck? Is it the little lever that moves - should it move, should it move freely, or should it resist being moved, and even spring back to its start position?

I have two of the valves doing the latter - resist movement and spring back. One valve however has free movement of the lever and does not spring back.

If one (or two) are therefore faulty, can I ask advice on what the likely cost of replacement/repair will be as for obvious reasons things are a bit tight at the moment and I'd like to avoid an unexpected bill, or at least get an idea on likely cost so I can make some informed enquiries with a local tradesperson.

Many Thanks in advance for any words of wisdom and support.
Stephen

 

[terryplumb]

Turn mains power off to heating system/ boiler. The zone valves will most likely return under spring pressure to closed position. Then try the manual lever on each one , if one has no resistance that would be the faulty one .

 

[stemcgoo]

Turn mains power off to heating system/ boiler. The zone valves will most likely return under spring pressure to closed position. Then try the manual lever on each one , if one has no resistance that would be the faulty one .

Yep, so the top valve, that lever is loose. Doesn't spring back. That's the same before, as well as after I've turned off the mains for the CH.

 

[terryplumb]

Show us a pic of the valve showing its make / model I.D.
It sounds like it's jammed open and probably needs replacing.

 

[stemcgoo]

Here you go.
Thanks again!!

 

[terryplumb]

It's jammed open and probably needs replacing.

 

[stemcgoo]

Can I just check, this "motorised valve" that seems to have failed - under my Home Emergency Cover policy documents, would this be covered as an "emergency" ?

 

[terryplumb]

You could contact the insurers and ask them. Policy's vary ,as to what's covered/ what isn't.