Heating not turning off

[noidea121]

Hope somebody can help.

Keston Q28H boiler
Drayton LP241 controller
Honeywell thermostat.

I have turned the heating off at the control and turned the thermostat to 0, but my boiler still indicates heating is being called for and is running it at max temp. Any advice?

 

[cbiscuit]

It sounds like an electrical controls issue, you need someone to test it. I would start from the boiler and work backwards through the controls...

 

[picasso]

Look for one of these

honeywell 3 port

• picasso
• 18 Oct 2010
• 26

or two of these

honeywell 2 port

• picasso
• 18 Oct 2010
• 31

probably near the hot water cylinder, the valve maybe stuck that is why your heating wont turn off.

 

[noidea121]

Look for one of these

honeywell 3 port

• picasso
• 18 Oct 2010
• 26

or two of these

honeywell 2 port

• picasso
• 18 Oct 2010
• 31

probably near the hot water cylinder, the valve maybe stuck that is why your heating wont turn off.

Will do, by stuck you mean the valve needs replacing or is there a 'setting' to change. There is a megaflow tank, if that helps.

 

[noidea121]

I can't find the valves exactly as you have in your pictures but there are 2 black boxes with the words danfoss motorised valve. One has a switch in 'manual open' position the other has it in 'auto'.

 

[picasso]

Depending on how old your valves are you might be able to change the head only, can you post a picture of the valves ?

 

[Armo74]

Is the one in the manual position on the heating circuit?

 

[noidea121]

Here are the pictures. The one that is vertical is on 'man open'. The horizontal one is on 'auto'. I have no idea what each one is connected to.
Second photo shows both valves one behind the tank and one vertical.

Untitled

• noidea121
• 28 Jan 2014
• 1

Untitled

• noidea121
• 28 Jan 2014
• 1

Both valves in one shot. One behind the tank.

Untitled

• noidea121
• 28 Jan 2014
• 1

 

[picasso]

Doesnt make a lot of difference where the lever is if the microswitch has stuck.

 

[noidea121]

Doesnt make a lot of difference where the lever is if the microswitch has stuck.

Should both switches (small stick out of box) on both boxes be on auto?

 

[mogget]

Yes, and if the heating then doesn't come on, it's likely that the motor on the CH zone valve has failed.

If the boiler still keeps firing when the lever is set to auto, then the microswitch is the likely culprit.

 

[mogget]

To clarify, if the heating doesn't come on but the boiler keeps firing, it's the microswitch.

Or someone has bodged the wiring.

 

[noidea121]

This morning everything seems to be working. Thermostat and controller, control the boiler, I did get an error message on the boiler once though.

"E24
Return exceed flow temperature by 10C - check direction of water circulation and operation of flow and return thermistors."

turning the boiler on and off has removed the message. And like I say the timer controller is controlling the on off functions and thermostat the temp.

I also noticed the lever in one box moving between 'open man ' and the 'auto' position. Is that normal. Could it be dirt that stops it functioning?

 

[noidea121]

Sorry for continued updates. Just to clarify when I turn the heating on, the lever on the vertical black box in the photo moves from the auto position to the manual position by itself . if I then turn the thermostat down (with the heating timer still on) it moves from manual back to auto. Is this all normal. The lever on the horizontal box seems to stay on auto the whole time.

 

[mogget]

That's nothing to worry about, as long as it moves back when the heating's off. Is it all working now?