hot water no heating

i can talk you through it if you have a multi meter???

 

Sounds as if your pump is at fault, can you check if its running?

 

the pump is obviously fine..... it is another external control

 

I'm betting its the syncron motor in the 3 port valve.

 

i agree...... but lets make sure.... lets work through it

 

Mr Blobby... have you a electrical test meter, and know how to use it?

You'll need to be confident at live testing!

Have you tried moving the lever on the end of the 3 port valve, to ensure its not siezed up?

It could be stuck in the hot water only postion, because either the spindle is seized up, or the syncron motor is jammed.

 

there's no easy solution here..... why not start at the basics.

i get the vibe that not many people here know the basics of ch wiring

 

well it is a DIY forum, and agree that electically testing CH wiring is advanced DIY skills, and would involve live testing, which is dangerous, if you dont know what your doing.

Also the "feel" of a 3 port valve is only gained from experinace.

 

i bet it is the 3 port. but maybe not.
I'm here to help people in a logical sequence. I guess you're right that 240v testing should be left to qualified persons

 

Mr Blobby,
You have confirmed that the three port valve moves under its own steam.

Set the heating control to hot water and heating.
Turn the roomstat up high.
Go to the airing cupboard and confirm that the pump is running.
Now turn the tank stat down so that the system thinks the hot water is at the correct temp.
The pump will switch off as the 3 port valve moves to the heating position only.
If it is working then the pump will fire up again.
If not, you can remove the cover (beware its live in there) of the 3 port valve and depress the micro switch. If the pump fires up then it means that your room stat is ok and your valve is not moving to the heating side far enough.
This could be a dodgy motor or a sticky valve. Its like ly to be the latter that has weakened / killed the motor.
I would advise changing the whole valve unit rather than just the motor.

I hope this makes sense and helps.

Cheers Mr Kip

 

Oh, by the way. If depressing the micro switch does not get the pump fired up then you will need to either get a multi meter as advised earlier and check the system or pay someone to do it for you cos it could be the controller, rooms stat, wiring fault or one of several other things.