Hive - yet another install problem!

[PST]

Wiring

• PST
• 28 Nov 2020

Hive

• PST
• 28 Nov 2020

Backplate

• PST
• 28 Nov 2020

Hi Everyone,

I’d really appreciate your help on this one. I realise that there are already lots of posts about wiring up a Hive receiver, but I still can’t get this sorted, so if any of you can advise me I’d be very grateful.

I have a Worcester Bosch 70/90-000-NI-L oil fired boiler. It is currently controlled by a wireless Honeywell Digital Thermostat/Timer paired with a Honeywell BDR91 wireless relay box.

I’ve installed the Hive hub and wireless thermostat no problem and I tried installing the single channel receiver. They all talk to each other OK and indicate that the boiler is on when it should be, but the boiler isn’t firing up. I’ve put the old Honeywell receiver back on and triggered it manually, and the boiler starts up correctly. So I think it may be to do with the wiring on the new Hive backplate.

I’ve attached a photo and sketch of how the Honeywell is currently wired and of course the diagram of the Hive single channel backplate which has been posted on here lots already.

I think the issue may be to do with the loop from A to L on the Honeywell receiver, but I’m not an electrician and have no idea how (or if) to replicate this with the Hive.

Thanks in advance for your guidance.

 

[muggles]

Loop L to 1 on the Hive

 

[PST]

Muggles
Thanks for replying so quickly. Before I damage anything (or myself!) can I just check that this is what you mean?
Thanks

 

[ianmcd]

yes that is correct, but you show the wire from 3 in the hive as blue , some others reading this post will assume it is a neutral, it is not , it is the switched live and should be Brown

 

[jackthom]

In the initial setup the brown was switched Live and the blue was Neutral. That doesn't match up to the new wiring.
Is it installed in the same location?

 

[stem]

This is how to swap the Honeywell for Hive, like for like.

However. It appears that there is no permanent live going to the boiler shown in your diagram. Not all boilers need this, but it may be, that the boiler has a separate mains supply fed from elsewhere. If so, this is not ideal. Both devices (Boiler and Controls) would normally be supplied from the same fused supply.

 

[PST]

Thanks everyone for your help – this is a great forum!

To answer Jackthom’s question, yes it’s a straight swap to replace the Honeywell receiver with the Hive single channel receiver.

If I’ve understood correctly the attached diagram corrects the brown/live and blue/neutral from the boiler side. The difference between this and stem’s diagram is that you show the boiler blue/neutral connecting to the N terminal on the Hive, but I think other’s thought it should be connected to the 1 terminal.

If I try one or the other until it works am I likely to damage anything?

 

[stem]

That doesn't make a great deal of sense to me unfortunately. Hive Terminal 1 is a live, as is terminal 3 so you are sending a 'permanent live' and a 'switched live' to the boiler. There's no neutral shown going to there. And as others have said, this doesn't match up with your original diagram, which shows a 'switched live', 'neutral' and 'earth' going to the boiler

We can only assist if you give us the correct information to work from.

So, based on your original information, if this wiring schematic you posted is correct.....

.....then this is the like for like exchange using a Single Channel Hive

However, if your original schematic is not correct, then you need to provide the correct information, before anyone can advise.

 

[PST]

Stem,
Thanks for your help. The original schematic is correct. So I'll go with what you have shown above and report back.

 

[Madrab]

Yep, You are confusing things with that blue wire. The only wire that comes from the hive to the boiler will be the brown switched live, from terminal 3. There is nothing to be taken from terminal 1,2 or 4.

Is your boiler powered from a separate L/N/E from an FCU?

 

[ericmark]

This seems the correct version

Note change to neutral wire, as said normally the supply is no simply plugged in, no reason it should no be plugged in other than chance it is then unplugged in error, normally use a single fused connection unit (FCU) for all central heating.

When I moved into this house found 3 FCU's and a plug feeding the central heating some from a fuse box, and others from a consumer unit, it did not work correctly and was dangerous, and it seems unusual to have an oil boiler that does not also do DHW in some way. So I suspect there is some thing missing?

 

[stem]

Is your boiler powered from a separate L/N/E from an FCU?

That's a good question, I mentioned it earlier. However not being overly familiar with oil boilers I looked at the circuits for a WB 70/90 on line, if you put the two diagrams below together, it appears that the only 'Live' connection that is required is a switched live from the controls, if this is the case a separate FCU isn't required.

@PST don't try to relate the above diagram to your actual installation, it's only been posted to show that the L terminal [Shown in the red box on both diagrams] is a switched live from the controls, and not a permanent live.

 

[PST]

Madrab, thanks for your comment. No, there is no other power supply to the boiler, only what comes through the wireless receiver.

 

[stem]

Ha ha, our posts must have crossed in the ether. Looks like you're sorted now. Sorry if we confused you.

 

[PST]

Thank you all for your help. It's all up and working correctly now thanks to your collective help. For the record, and for anyone who has the same issue, here's the final working arrangement. Stay safe everyone and have a great Christmas!