Central heating problem

[Phil farmer]

Hi I'm having a problem with my heating
Tried it last night and the boiler kept turning off too early and the radiators are not getting hot

Today I have changed the room thermostat , no different
Then I went to the motorised valve , after manually opening and locking open everything seemed good

So I thought it must be the motor
Wired a new motor on but not put it in the valve , tried to run heating to check if motor turned and it doesn't.
I don't know what to try next or what the fault may be
Please help

 

[stem]

First of all you don't say what type of motorised valve you have. In particular if it is a two port, or three port valve. If it is a three port valve, then the white wire should receive a switched live from the controls when central heating is required. From what you say, it would appear that this is not happening, so the wiring to the white wire will need tracing back through the various components, by a competent person with the appropriate test equipment to see where it is lost.

If you have a two port valve, it is the brown wire that receives the switched live from the controls.

The neutral connection should also be tested for continuity, loss of the neutral does happen but is rare.

Also, unlikely I know, but you could have two faulty motors, but these can easily be bench tested.

 

[Phil farmer]

It's a two port I think the control panel is faulty

 

[Phil farmer]

Changed the control panel and it still has the same fault if I open the motorised valve and lock it in position everything works fine, why won't the motorised valve open itself

 

[cozzmic]

motor goosed in valve.

 

[Phil farmer]

Motor fine it's been replaced

 

[picasso]

Buy a multimeter .

 

[bernardgreen]

Buy a multimeter .

and learn how to use it and interpret the reading it gives you

 

[Phil farmer]

We have no supply on the motor for some reason the

The control panel is ok but we have a supply fault somewhere

 

[stem]

Why won't the motorised valve open itself?

Because it is faulty, or not getting power to it, so you need to check:
a) The neutral wire is actually connected to a neutral, this will have to be done with a multimeter, not visually
b) If there is no live present at the valve, then you will need to trace the live connection from the valve back through the various components to find out where it is 'lost'.
Changing components in ah 'ad-hoc' manner hoping that you will stumble across the problem is an expensive way of fault finding and more often than not doesn't resolve matters.
If you can do it safely, the valve can be tested in situ, by simply wiring the valve's N, L & E to a plug and seeing if it operates when plugged in separately from the heating system controls.

How do you know that the valve is not opening? Is this an assumption, or can you see that it doesn't open? I say this because it is possible for a valve to be opening, but the boiler and pump are not switched on by it when it does.

 

[Phil farmer]

There was a electrical problem on the motor for the motorised valve and room thermostat
It's fixed now

 

[FiremanT]

There was a electrical problem on the motor for the motorised valve and room thermostat

I'm glad that's crystal clear

 

[stem]

There was a electrical problem on the motor for the motorised valve

You were unfortunate that the original motor and the new one that you replaced it with were both faulty.