Ongoing CH problems

[TryItTom]

Hi all

Once again my CH has stopped working, but I still have HW.

Pump running ok, HW comes on when called and fires the boiler. CH does not come on or fire the boiler when called.

I installed a new mid position valve in August, and the system has worked fine until two days ago when the CH cut out.

I managed to get the CH going by placing the valve in Manual, but the lever won't stay in Manual and within 10 minutes has set itself back to Automatic and it turns the CH off in the process.

I had the HW and CH set to timed last night, and both came on this morning and the CH ran until the time-off setting.

I've now selected CH on (permanent) and nothing. Boiler not firing.

I've also tried switching the HW on as well as CH to see if the CH is being called only when HW is, but that hasn't worked either. The pipe from pump to valve is hot, as is pump from valve to HW. Pipe to CH is cold.

I can't believe the mid-position valve has packed up already (after only 3 months)

If there is an airlock or sludge in the system, could this be causing the issue? And how can I force the CH on?

Thank you for your help,
Tom

 

[spraggo]

Your symptoms indicate that the syncron motor in the 3 port valve has packed up or it is not receiving power when CH is selected.

 

[TryItTom]

Thank you

Is it easy to replace the synchron motor?

Tom

 

[picasso]

check to see if the orange wire from the 3 port isint loose in the junction box.

 

[TryItTom]

Thanks for the suggestion Picasso, but I've checked and the orange wire (and all others) are secure.

Anyone know why I can't get the valve to stay in the manual position?

Tom

 

[picasso]

some 3 port valves are designed to return to auto when they are powered, I think drayton is one of them.

makes more sense returning to auto

 

[spraggo]

Your symptoms indicate that the syncron motor in the 3 port valve has packed up or it is not receiving power when CH is selected.

You state that if you hold the lever in the manual position the heating works. As I have already stated, this indicates that the synchron motor is not functioning correctly, or it is not receiving power. When heating is calling the brown and blue wires, from the valve, should be live at 240v.

 

[MANDATE]

Hi all


I had the HW and CH set to timed last night, and both came on this morning and the CH ran until the time-off setting.


Thank you for your help,
Tom

The fact that both came on indicates the valve moved to mid position so the motor isn't dead altogether.

There are two micro switches within the actuator head with a total of four contacts.
1 set of contacts brings the grey wire into operation and if faulty would not allow valve to move beyond mid position.
Also 1 set of contacts switches power out through the orange wire and if faulty the boiler will not light even though the valve may have moved to the correct position.
I would suggest changing the head, that way you get new micro switches as well as a new motor.

 

[spraggo]

Your symptoms indicate that the syncron motor in the 3 port valve has packed up or it is not receiving power when CH is selected.

You state that if you hold the lever in the manual position the heating works. As I have already stated, this indicates that the synchron motor is not functioning correctly, or it is not receiving power. When heating is calling the white and blue wires, from the valve, should be live at 240v.

 

[TryItTom]

Thanks to everyone for taking the time to offer guidance and help.

The BG Engineer has been and also diagnosed that the motor had packed up. With a little negotiation, and through his own good will, he has replaced the whole head rather than just the motor, so I have new switches as well...

Heating fixed.

It is much, much easier to deal with these issues thanks to this forum and its knowledgable members.

More money saved!

Cheers,
Tom