Replacing a motorised valve

[fossyant]

It appears that our motorised valve on the central heating is 'playing up'. Standard boiler, hot water tank and 3 way valve on the wall next to it (and associated pipework).

We've noticed the upstairs radiators come on when just the hot water is on - turned off the radiators and the downstairs ones are now warm - so it's not all the rads so I'm suspecting the valve isn't fully closing on the heating circuit.

It looks like I have stop taps on all the pipes leading to the valve, so I shouldn't need to drain the system, just isolate the valve (don't want to as it I drained it last year and all new inhibitor put in).

Easy DIY job ? Only issue I can see is moving the pipes enough to get the old valve out and new in before tightening back up.

The valve has been there 27 years so can't complain.

 

[TissoT]

Isolate via the stop taps .
Undo the MV slightly if there's pressure on it after closing the valves you will need to drain off the system
Easy job providing the MV is assessable otherwise extent the pipe work so its easier to replace.

 

[fossyant]

I only know it will be accompanied by a bit of swearing getting access to the pipe connections. I'll open up the junction box and take a look at the electrical connections before ordering the correct replacements.

 

[slowmotion]

It's usually just the valve motor that dies. You can often get a replacement.

 

[fossyant]

It's usually just the valve motor that dies. You can often get a replacement.

May just wait to see what happens as don't fancy putting heating on to check what's happening. It's a honeywell and the motors are available.

 

[Venod]

I have changed the motors on ours a few times, synchronous motors from Screwfix or Tool Station, cheaper ones are available on the internet but maybe not as good.

 

[slowmotion]

I have changed the motors on ours a few times, synchronous motors from Screwfix or Tool Station, cheaper ones are available on the internet but maybe not as good.

Genuine Honeywell replacement motors can be as much as £45. Knock-offs can be found for £15 or less from Amazon etc. It might be worth a punt. BTW, there are clips on Youtube showing how to install a new motor.

 

[Deleted member 26715]

Usually 2 screws holding the motorised part, remove the valve & operate the controls you should see the motor move, I suspect it won't. You can then play with the valve on the wall & just set it in the HW position which will close the CH

 

[CXRAndy]

Corrosion will be most likely difficulty. Buy the best Honeywell valve. 27 years testify to their quality

 

[fossyant]

Brand new genuine Synchron motor for £23.99 from Screwfix. So far boiler just coming on for a short time (I assume tank circuit at temp) rather than running on. I've been turning the hot taps on for a bit.

So far radiators have remained cold.

 

[fossyant]

Corrosion will be most likely difficulty. Buy the best Honeywell valve. 27 years testify to their quality

That's next on list if new motor hasn't cured it.

 

[newts]

Try the manual overide lever on the end of the housing first. If you can't turn the valve manually it is probably the valve sticking. If you can operate the valve manually, then most likely the motor is fubar.

 

[fossyant]

Try the manual overide lever on the end of the housing first. If you can't turn the valve manually it is probably the valve sticking. If you can operate the valve manually, then most likely the motor is fubar.

That moved fine but wasn't 'returning when I didn't 'lock' it into place, new activator and it slowly rolled back to auto.

 

[fossyant]

Heating/hot water appears to be doing the 'right thing' - tested heating only last night and the radiators started to get warm - turned off after two minutes. Hot Water set back to constant, drew hot water off, radiators didn't change. This morning hot water had been on (warm boiler), radiators stone cold. Phew.

 

[fossyant]

Still working correctly.