Drayton controls - water ok, but no heating

[chatlow]

Hi all

We have an old system boiler with a slightly more modern drayton controller and thermostat. Water is being heated fine (some pipe noise but nothing major)
Tried heating and it turns on (not selecting timed) at the controller with yellow light but the boiler isn't firing. Thermostat has been turned up and I can hear a click when it goes above room temperature.
Any ideas what the issue might be??

 

[CBW]

If everything else is definitely working as it should, I’d be looking towards the motorised valve. Do you have any test equipment?

 

[chatlow]

If everything else is definitely working as it should, I’d be looking towards the motorised valve. Do you have any test equipment?

Unfortunately not, I'm also not very familiar with system boilers. Had planned on changing it out to a combi or maybe a heat pump but for now, we're using it as just moved in. I'm yet to bleed the rads but can't see that causing a problem like this

 

[CBW]

I'm yet to bleed the rads but can't see that causing a problem like this

Actually you’d be surprised, however if hot water isn’t working I doubt it would be an air lock, although not impossible. Do the radiators need bleeding? Have a look at the motorised valve, it might have a detachable (replaceable) head, if unsure, post a photo of cylinder cupboard

 

[RandomGrinch]

The Drayton controller and thermostat are basically just simple switches.
If you remove them from their back plates, a temporary link can be made to bypass the controller.
If you still have the same problem, you have at least ruled out a problem with the controls.
As @CBW says, it's well worth investigating the motorised valves.

 

[chatlow]

Okay will check tomorrow. Sorry the motorized valve is with the water cylinder or part of the boiler? Everything else (as in water) works well

 

[CBW]

With the cylinder usually

 

[chatlow]

With the cylinder usually

Ta. Would you still be thinking it's this valve even though the boiler is not firing up?

Will check tomorrow and also bleed to system to rule that out

 

[CBW]

Ta. Would you still be thinking it's this valve even though the boiler is not firing up?

Will check tomorrow and also bleed to system to rule that out

Yes, the boiler fires up when the valve microswitch is activated when the motor drives open, which then sends a switch live to the boiler to fire up for that particular demand.

 

[chatlow]

Attached a pic of the water cylinder. Like I say, this system is old and will be replaced soon, but for now, would love to get this working

 

[CBW]

Attached a pic of the water cylinder. Like I say, this system is old and will be replaced soon, but for now, would love to get this working

Ok, so you don't have a motorised valve, you have a thermal store with twin pumps. Could be that one if the pumps isn't sending a signal, but I'm out if my depth as I don't know how these work

 

[chatlow]

no problem. If anyone has any other thoughts, I'm all ears! I've fiddled with the boiler gauge (ideal classic 0-6, recommends 3/4 during summer, 5/6 in winter) but no joy.
Don't see any other controls other than a red reset switch on side of the boiler which Im dying to press, but won't yet
Yet to take cover of thermostat to check thats OK, but it clicks at room temp, so it seems it :-/

 

[CBW]

There'll be a few who's familiar with your setup, might just take them a day or 2 to respond

 

[Johnmdc]

With a thermal store for the heating to work the hot water has to be turned on too, you can't have heating on on it's own.
Depending on which controller you have it would usually be set to gravity mode so when you select heating it automatically turns hot water at the same time.

 

[chatlow]

With a thermal store for the heating to work the hot water has to be turned on too, you can't have heating on on it's own.
Depending on which controller you have it would usually be set to gravity mode so when you select heating it automatically turns hot water at the same time.

Controller is Drayton LP522. There are settings both water and central heating to be run independently of one another, including timers for each, so the above would be massively surprising if true.
I'm not seeing gravity mode of any kind. I've also turned on the CH with the water ( so the boiler fires up) but the heating is not working