Central Heating Question - Why wont it work?

[LondonStone]

Ok now I think I'm going slightly mad.
Took off the control panel, connected the live upto terminal 4 as you suggested and CH came on for abuot 1 min, then shut itself off.

So I followed the live feed all the way through to the motorised valve, to try and work out where the break was happeneing. And guess what? There is a live feed at the brown wire in the motorised valve. Even though the valve just switched itself off.

So now I'm guessing it's a dodgy syncro motor, or something wrong with the valve itself.
Could it be anything else?
This is really confusing me.

 

[LondonStone]

Cracked it! Well hope I have anyway.
It was that motor.
I took it off of the valve and turned on the central heating. The cog spun for about a minute, the motor got very hot, then it stopped spinning.

Problem solved.

Very strange for a new motor to do this though, do you oocasionally get a dud? Or might something else have caused the problem?

I'll fit a new one and see if it works.
Thanks once more for all the helpful advice. I've really learned alot about my central heating system!

 

[meldrew's_mate]

Jolly good show, it's unusual for sync motor to fail if you use decent quality ones. I came upon one recently where the top cover just came off or pushed down (stalling the motor) depending in where I put my hammer!

Glad to see you'll have fixed it by tea-time, no sugar for me, but those chocolate hobnobs look nice...

 

[LondonStone]

Put on a new motor and it's working a treat.

Help yourself to as many hob nobs as you like!

I have noticed that since the heating has started working again, the pump is making a strange shwooshing fizzing noise. Like bubbles of air are going through it.

I've bled all the rads and can't find any air in the sealed system.
I wont let it keep me from those nob nobs but Is it anything to worry about?

 

[slippyr4]

did you bleed the pump? big screw in middle.

 

[LondonStone]

no, but I will now! Thanks