Drayton LP522 not firing central heating

[BowerHinton]

I have a Drayton LP522 programmer controlling a non-condensing Baxi gas boiler (i.e. with a hot water tank) in a high pressure system (no cold water tank).

When heating is selected the boiler doesn't fire up although the room thermostat clicks OK and it has worked fine in the past. Hot water works fine. I've had the boiler serviced recently and the man said it was working fine. Is there any way I can find out where the problem is? (e.g. room thermostat, LP522 programmer, boiler or mid-position three way valve connected to the hot water tank)

And a related question, should I call a plumber or an electrician?

Many thanks for any help.

 

[learnplum]

Do you possess a voltage measurement device?:tounge_smile:

 

[BowerHinton]

Yes, I have a digital multimeter and can measure voltages if I knew where.

 

[AWheating]

if the boiler runs on hot water its not the boiler, its going to be either the clock, room stat or the most likey the motorised valve.

 

[Aquazone]

First check I would do, turn off HW on the clock, turn on HTG and turn up room stat. Look at valve to see if lever is floppy, and also take valve head off and check its not a seized spindle stopping it moving all the way over.

If that offers no solution, and you are confident live testing then you can look for voltages in wiring centre. Or call a plumber.

 

[Leo21]

Iff your competent with electrical testing, you need to check you've got power through your room stat. If you get stuck, call a heating engineer. Electricians are uber useless normally on heating electrics.

 

[learnplum]

Turn clock to heating only and put stat to max setting.
There should be an electrical join by the cylinder.
Look for the white cable on the valve, and see if there 230volts on it.
If there is check to see if there is now 230v on the orange cable of the valve.
If 230v on white and zero volts on orange, then internal switch in valve knackered.:tounge_smile:

 

[Leo21]

Turn clock to heating only and put stat to max setting.
There should be an electrical join by the cylinder.
Look for the white cable on the valve, and see if there 230volts on it.
If there is check to see if there is now 230v on the orange cable of the valve.
If 230v on white and zero volts on orange, then internal switch in valve knackered.:tounge_smile:

Or you could check power to the sycron motor.

 

[learnplum]

Another check you could do, to make sure its wired correctly in the first place, is when you put the clock in heating only, and stat on full, check the grey cable on the valve is at 230v.
So you want 230v on the grey and white, so then the orange will recieve 230v and fire the boiler up.:tounge_smile:

 

[Leo21]

Another check you could do, to make sure its wired correctly in the first place, is when you put the clock in heating only, and stat on full, check the grey cable on the valve is at 230v.
So you want 230v on the grey and white, so then the orange will recieve 230v and fire the boiler up.:tounge_smile:

Unless it's never worked, it's going to be wired right.

 

[learnplum]

I beg to differ.:tounge_smile:

 

[Leo21]

Beg away my good man.

 

[learnplum]

Hi leo most Y plans are wired wrong, but customers live with it?:tounge_smile:

 

[Leo21]

I beg to differ.

 

[learnplum]

Hi leo, the domestic hot water off, facility was never used on old systems?:tounge_smile: