Motorised Head Valve v Boiler

karlitob

Hi all

Appreciate your advice please.

I seem to have an issue where the boiler temperature is turning on and off one motorised head valve (downstairs rad; there are three zones).

- it’s not the valve itself. It’s turning on and off fine - automatically and override. There’s a good flow and return either side of the valve.
- it’s not the room thermostat. It’s turns on and off the head valve fine (but depending on boiler temp)
- it’s not the boiler per se. Upstairs and the hot water are fine.


But when the boiler gets to max temp - it’s turns off (as you’d expect) but it also turns off the motorised head valve, despite the room thermostat calling for heat.

When the boiler comes back on (after it drops down to a certain temperature), then the motorised head valve opens again and hot water flows to the rads.

So clearly there’s some problem between the boiler and the motorised head valve.

So
- does the full valve need to be replaced (drain down etc)
- does the actuator need to be replaced
- or is this an electrical problem that needs an electrician


Thanks as always.

jimf

boiler type gas / oil and location

karlitob

jimf wrote: »

boiler type gas / oil and location

Flexicom 18x. Gas.
Downstairs in the kitchen (hope that’s what you mean).

jimf

karlitob wrote: »

Flexicom 18x. Gas.
Downstairs in the kitchen (hope that’s what you mean).

its just boiler type and location can sometimes help with the wiring set up etc

has it always been this way or a new problem

meercat

Without seeing this installation,I’d say it’s a wiring problem

karlitob

jimf wrote: »

its just boiler type and location can sometimes help with the wiring set up etc

has it always been this way or a new problem

Understood.
New problem - only since last week.

karlitob

meercat wrote: »

Without seeing this installation,I’d say it’s a wiring problem

I was thinking the same thing.

Would you think it’s the head itself or the wiring on the box that’s near the hot water cylinder where all the motorised valves / programme controls go?

Is it possible to replace just the actuator - it’s a horstmann F222m. Or is it the whole valve inc draining down the system.

jimf

if your other valves are of the same type can you just switch actuator heads from one valve to the other

if problem persists it gives you an answer

karlitob

jimf wrote: »

if your other valves are of the same type can you just switch actuator heads from one valve to the other

if problem persists it gives you an answer

Great idea. But no - those two were changed to Honeywell’s a few years ago. Not the same problem - those just stopped working ...motor wouldn’t turn valve.

Are all motorised head valves interchangeable. If I buy the actuator of one will it fit on the valve of another?

jimf

no they are not interchangeable some will fit others I think

ask in your local heating suppliers they should be able to help unless the valves are very old you should be able to get actuators on their own

karlitob

jimf wrote: »

no they are not interchangeable some will fit others I think

ask in your local heating suppliers they should be able to help unless the valves are very old you should be able to get actuators on their own

Thanks for your help.

meercat

karlitob wrote: »

Understood.
New problem - only since last week.

If it has happened only recently then it’s unlikely to be a wiring problem unless it was always like this and you’ve only just noticed
My gut instinct though is that’s it’s a wiring problem in the control centre joint box.
The actuator seems to be connected to the switched live
My recommendation is an electrician to investigate further

karlitob

meercat wrote: »

If it has happened only recently then it’s unlikely to be a wiring problem unless it was always like this and you’ve only just noticed
My gut instinct though is that’s it’s a wiring problem in the control centre joint box.
The actuator seems to be connected to the switched live
My recommendation is an electrician to investigate further

Thanks for reply. Definitely new problem.

I had wondered about wiring box alright. Perhaps it could’ve been pulled.

I think plumber is coming out today. Good guys but I’m worried about the cost of a full drain down which won’t fix things cos it’s an electrical problem.


Many thanks.

meercat

karlitob wrote: »

Thanks for reply. Definitely new problem.

I had wondered about wiring box alright. Perhaps it could’ve been pulled.

I think plumber is coming out today. Good guys but I’m worried about the cost of a full drain down which won’t fix things cos it’s an electrical problem.


Many thanks.

Get someone to turn the thermostat on the boiler on and off while you are standing beside the valve and then you can see if it’s operating incorrectly.

karlitob

meercat wrote: »

Get someone to turn the thermostat on the boiler on and off while you are standing beside the valve and then you can see if it’s operating incorrectly.

Good idea. Will do that.

Since earlier - took the actuator off the valve, with valve open. Downstairs heating didn’t work when downstairs call for heat turned on. Upstairs call for heat turned on and downstairs heating worked.

Nearly sure now that it’s the junction box.

karlitob

karlitob wrote: »

Good idea. Will do that.

Since earlier - took the actuator off the valve, with valve open. Downstairs heating didn’t work when downstairs call for heat turned on. Upstairs call for heat turned on and downstairs heating worked.

Nearly sure now that it’s the junction box.

I just can’t find where how the motorised head valve gets to the junction box.

I can see the two other valves clearly. I’ve pulled and tugged (gently) on the faulty valve and can’t find it at all.

Any suggestions.

jimf

are you sure its not wired in with the boiler somehow somewhere

karlitob

jimf wrote: »

are you sure its not wired in with the boiler somehow somewhere

I think you’ve hit the nail on the head.

So - all the wires in the junction box are fine.

I can’t find the wire from the downstairs valve to the junction box. I even lifted the floorboards from above - no joy. It’s buried in the ceiling somewhere - I think I know where it is but I’ll have to cut a hole in the ceiling of the under stairs.

So as you say - I think it’s wired into the boiler somehow. The plumber who redid our two valves upstairs a few years ago did say something about mad wiring.

So even if I do find a replacement actuator (plus or minus having to do the whole valve) I’m concerned that we won’t be able to find the wiring. Presumably I shouldn’t mess around with the soldering and motherboard of the switch mechanism in the actuator

One other thing of note. I had turned off the 3A spur and the whole house fuse for looking at the junction box. I turned back on the house fuse but actually forgot the put on the 3a spur - I turned on the upstairs rads and it worked. I thought the 3A turned it all on/off. Am I wrong on that?

I’m wrecked thinking about this. Thanks for your help.

jimf

god only knows what way your wiring is set up

I think at this stage you need a good rgi who knows how to use a multimeter and is good with electrics

I don't do gas oil only and by jesus you do see some over complicated installs

the 3a fused spur should be on the electrical supply to your boiler

karlitob

jimf wrote: »

god only knows what way your wiring is set up

I think at this stage you need a good rgi who knows how to use a multimeter and is good with electrics

I don't do gas oil only and by jesus you do see some over complicated installs

the 3a fused spur should be on the electrical supply to your boiler

Thank you. Good advice.

It is disappointing though - we did a full house refurb in 2011. All plumbing, electrical and insulation.

“The 3a fused spur should be on the electrical supply to your boiler”
- does this mean ‘yes, everything should’ve turned off’.

jimf

karlitob wrote: »

Thank you. Good advice.

It is disappointing though - we did a full house refurb in 2011. All plumbing, electrical and insulation.

“The 3a fused spur should be on the electrical supply to your boiler”
- does this mean ‘yes, everything should’ve turned off’.

sorry cant help with an ans to should everything turn off I don't know

a few of the other lads on here will be able ans when they see this later

I do seem to remember a post on here a few years back stating it should kill the whole system

jimf

may be talking gobbly gook but I wonder would this set have anything to do with the boiler overheating

I think im correct when I say all gas boilers have a pump over run

where are the gas boys when we need them like gary and dgobs

meercat

karlitob wrote: »

“The 3a fused spur should be on the electrical supply to your boiler”
- does this mean ‘yes, everything should’ve turned off’.

Yes. The fused spur should turn off your boiler and all control circuits.
My advice is to get a rec out and rectify or possibly redo the boiler circuit and controls.
A good rgi with knowledge of electrics would suffice,as others have stated