Hot water but no Central Heating...Doh!

[ivor67]

Hi Guys,

I've got a Glow Worm 40RR Regular/cylinder Boiler, hot water works fine (and diag neons X 4 light up upon PCB when fired up) But the Central Heating doesn't even fire up and theirs no neon diag lights appearing on the PCB, even the Power diag neon is off on the PCB.

I've replaced the PCB, sync motor in the midpoint valve and the room thermostat, if I put the Water on and the Central Heating the radiators get hot but at no point ever will the CH fire up by itself.

Checked valve markings - when program on HW shows W on valve, when program on CH shows H on valve and when program on both HW and CH shows Mid position on valve, but at no point will the central heating start by itself.....


Any ideas anyone why I get no power on the PCB only when the central heating is on and not the water all I can think the programmer is at fault..???


Cheers for any help folks

 

[seco services]

Either the valve is not making the micro switch or the micro switch/pcb is faulty.

When you say you have changed the pcb i take you mean the boiler one ?

Won't be the programmer or the stat as the valve is moving to H position so you are getting power to the valve through the white wire to move the valve over.

On heating only you should have 230v on the white, grey, orange wire.

 

[ivor67]

Hi Seco Services...

Yes new Boiler PCB fitted today along with Valve Sync Motor and can confirm 230v on the white, grey, orange wire, do you mean the switch in the valve ?

 

[seco services]

can confirm 230v on the white, grey, orange wire.

You have 230v on all these wires ?

do you mean the switch in the valve ?

Yes the micro switch.

 

[ivor67]

Yes have 230v on those wires, can the micro switch be just replaced Seco without buying the whole actuator..???

 

[seco services]

If you have 230v on the orange then you should have 230v to the sw/l for the boiler to fire up.

The hot water call from the cylinder stat is in the same terminal as the orange and you say hw is firing up.

If you have 230v on orange valve is not faulty.

 

[ivor67]

O'h that don't sound good I'll double check tomorrow and get back to you Seco, I've given the Multimeter back to the neighbour now..Thanks for your help.

 

[seco services]

Did this problem just occur or after you had any work done on the system/wiring ?

 

[ivor67]

Hi Seco.....Well

With just Heating switch on and Room Thermostat engaged I read:

White 0 volts

Grey 0 volts

Orange 230 volts

Hopefully I'm reading this right on the Multimeter ie..Red probe from meter to Live(Brown) then Black Probe to test above colours.

The answer to your other question is this problem just happend no work had been done on any wiring.

 

[seco services]

readings are wrong.
and probe on earth or neutral and red probe on white, grey, orange.

 

[ivor67]

Ok re-checked the results with probe on neutral and red probe on colours :

White 230v
Grey 230v
Orange 0 volts.. ?

 

[seco services]

Is the marker on the valve on the H position ?

 

[ivor67]

...Yes

 

[seco services]

Then the valve is either not making the micro switch in the actuator.
You can take the plastic lid off to check this.

Or the pcb in the actuator is faulty.
Either way the valves not sending 230v to the orange to fire boiler.

 

[ivor67]

Great stuff thanks Seco, I'll check the micro switch next see if its switching