Hive installation on Potterton Promax HE Store

[Lesta_SMSC]

Hello all,

I have been following the forum and tried searching various threads on Hive installation with Potterton Promax HE Store (Baxi) combi boiler but seems like I was getting even more confused due to some wiring arrangements. Decided to get a plumber to fit mine for me and low and behold - the Hive thermostat does not switch on my central heating. The hot water still works fine. I have tried various adjustments of the programmer on the boiler although I am told I need to leave this as ALWAYS on so that the Hive can control CH independently. The plumber has been over again and says he has checked all the wiring but cannot understand why the Hive is not working – he tells me the boiler is now at fault although before the changeover, the boiler worked fine with old wired thermostat (Honeywell CMT707A).

However, if I switch HW off and then cycle the boiler setting for CH to OFF and then to ALWAYS ON it will allow me to switch CH on / off with Hive. With the HW also being enabled, as long as I don't cycle the CH setting, the CH still works but then I am left with no HW. If I then do the reverse, i.e. put CH to off then always on but AFTER select Always on for HW, then only HW works.

I have 2 zones and both the thermostats have the issues as described above and the wiring is the same at the thermostat.

I took photos of the wiring of the original and the new wiring configuration as below:

Original boiler wiring:


Original thermostat wiring:



New boiler wiring:


New thermostat wiring:



Original boiler setting (when both HW and CH worked on demand):


Hopefully someone with a bit more knowledge on these can decipher where things have gone a miss. I can only assume there is an activation wire/link missing somewhere that is causing this since it worked on the old system and it has failed straight after swap.


Thanks in advance,

Lesta

 

[CBW]

Although it probably won’t be the issue, the black wire is crimped on the insulation in the Hive backplate. The old thermostat wiring, what happened to it?

 

[Lesta_SMSC]

As far as I can tell. The old thermostat was basically disconnected. The new 5 core wire was fed into the boiler terminal block. There is a motorised valve (wires coming out of black coloured core) which activate a switch that then switches on CH. Interestingly the motor still works and switch still activates but motor seems sluggish when doing the initial spin towards switch. Manual override on the switch also doesn't enable CH unless I switch off HW then cycle CH setting to OFF before going to always on. The boiler makes an audible click when this occurs as though it triggers a relay.

 

[CBW]

If you have testing equipment I’d be checking for correct voltages, if you don’t have the testing equipment I’d be getting your Hive installer back. Have you paid him yet?

 

[Lesta_SMSC]

Yes paid him already. He came back when I mentioned the issue but stated he has wired it correctly so no refund due. He is saying there is problem with boiler.

I have a multimeter if that is what you're referring to?

 

[CBW]

Yes, a multimeter is good. Set to Vac, and test it’s receiving the call signal from Hive 1st, to zone valve. Then check the microswitch makes which should be orange and grey. All should be 230/240 Vac.

 

[Lesta_SMSC]

Excuse my ignorance but can you talk me through which wires that correlates to?

 

[CBW]

My apologies, just re-gone over your post. It appears that the Hive has been wired incorrectly. You should have a wire in terminal 4 (hot water on) and nothing in 1 (currently grey). Chances are that grey is your heating on demand. Up to you if you want to move it.

 

[Lesta_SMSC]

But my hot water is not controlled by Hive? Mine is combi boiler. The Hive only controls the CH?

 

[CBW]

But my hot water is not controlled by Hive? Mine is combi boiler. The Hive only controls the CH?

Sorry, I was getting myself muddled up with another thread. So if you set the potterton ch to permanently on, and let hive control it, how is it you end up no hot water?

 

[Lesta_SMSC]

I end up with no HW if I off HW to allow CH to work in isolation.

 

[CBW]

I’m not entirely sure then, I’m not great when it comes to wiring, sorry.

 

[Lesta_SMSC]

No problem. Thanks for trying. I am inclined to just disconnect everything and wire up everything as it was bar the thermostat... but another part of me thinks it's a simpler fix. I'm not sure whether I should link L to 1.

 

[CBW]

I'm not sure whether I should link L to 1.

No, I wouldn’t do this, as there’s already what appears to be Live (from boiler) anyway.

 

[Lesta_SMSC]

Ok... I will have to wait for someone to advise further