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Discuss Air source heat pump heating issue in the Central Heating Systems area at ElectriciansForums.net
Right, before you start pulling things to bits you need to check whether there is power at terminal 9 of the heat pump wiring centre, see page 9 of the manual.
If you have 230 at terminal 9 then the HP is asking the MV to open, if there is no power then the HP is not asking for heating regardless of what the controller says.
I still think this is a parameter error or sensor fault.
If you have power at terminal 9 and no power at the MV then a broken wire you have, or a hidden JB.
The ones I've seen tend to power the MVs from the HP, the orange/grey being used to power pumps via contactors.
Is there and internal wiring centre? If so a loose connection in there may be the cause.
Junction box,Excuse my ignorance but what does JB stand for
It's a Honeywell but it doesn't appear to be working (heating is on no matter temp on stat) EDIT, scrap that, it works fine:It's difficult to see whats going on in that photo otherthan there is a call for heat as the pump is/should be running. I've never seen a buffer used like that before. What room stat do you have?
Junction box,
The one on the wall next to the switches.
You'll probably find a multi core flex going from there to the HP.
One core will go to terminal 9 on the HP and the heating MV should be connected here also.
I'm not sure what the three port is doing, especially in the position it is. Might be a return diverted.
Any joy with the engineers manual?
T9 should be a live feed to the heating MV, if I read the diagram correctly.And I assume I put 1 probe on the live wire and the other on terminal 9? Sorry I am a bit of a noob unless the electrics are very basic
T9 should be a live feed to the heating MV, if I read the diagram correctly.
It should be live in heating only.
Test between T9 and a common neutral not a live.
Let me know how you get on.
Any ideasJust looked at the wiring diagram in full screen, the heating MV could be being fed from other places further up the terminals.
Could yo post a picture of this from inside the heat pump.
Reply to Air source heat pump heating issue in the Central Heating Systems area at ElectriciansForums.net
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