Hive Dual reciever & combi boiler

[ericmark]

With many items we have a method to stop wrong devices being fitted, the GZ10 spot light has a right-angle, and GU10 a taper so you can fit GU10 into GZ10 holder, but not other way around, and the GU10L2 has a dimple in holder so only LED lamps will fit, although this now seems to be been abandoned.

But the programmer/thermostat back plate seems to be asking for errors to happen, specially when you can swap a volt free for a low voltage (230 volt) device without doing any rewiring.

They talk about all 230 volt for heating being taken from one circuit, then they do this, so on one hand accept people working on central heating have no idea what they are doing, then produce a back plate asking for mistakes to be made.

It does seem the idea of all being supplied from one circuit is a thing of the past, I see Nest very often the controller is supplied from a different supply to the base unit, fact that the 230 to 5 volt unit is independent to the controller is beside the point, we still have two independent circuits. But to be fair unlikely to cause problems as a result.

My router and the central heating are not on same circuit, but the wifi router is required for the central heating to work correctly. But to be fair the instructions say supply not circuit, and in most homes we only have one supply.

But however idiot proof we try to make things, we just find better idiots that can get around the protection, and we have to consider how far to take the protection, in the main if it requires a tool or a key to access, we assume the person working on it, knows what they are doing. Signs to say "This installation has wiring colours to two versions of BS 7671." should not really be required, if they don't know that, they should not be working on it.

 

[diydan900]

Ok, so there has been some very usefull information on this page which has led me to investigate how to get a dual channel hive working as a single channel system.

As mentioned previously, the reason why it's not a straightforward swap of wires is that a single channel receiver works as a switch between two contacts,
But the dual channel receiver works as a 240v supply from the contacts, not as a switch.

However, thankfully HIVE like to save money and the internals are almost exactly the same for both !
Just that there is two wires connected either in single mode or dual mode.
And best of all it seems only 1 single wire needs to be moved.

** DO NOT ATTEMPT THE FOLLOWING.
THIS WILL VOID ANY WARRANTY, AND IS MESSING WITH VOLTAGES.
IT IS STRONGLY RECOMMENDED THAT YOU PURCHASE THE CORRECT RECEIVER TO USE **

that said, im just going to document what i did.

Basically youre looking to do the following... View attachment 283447


And all it takes is moving 1 single wire which is currently connected to live, over to PIN 1...

View attachment 283448this is the common of both relays currently connected to L

View attachment 283449
This is where it needs to be disconnected from L and reconnected to 1

View attachment 283450
This is the finished change.

Notice i have simply connected it to the existing wire going to pin 1.

Two reasons- keeps job simple, no need to disconnect the wire already at PIN 1, since in normal state its NC and so basically looping on its self.
And so that i could easily unsolder it and move it back to L if in the unlikely even i want to chnage it back.

So i wasn't too worried about the connection since its only going to be switching a low level 24v signal, rather than a 240 feed.


Once this is complete, you can wire the backplate to pins 1 and 3 just like on a single channel receiver. However pin 3 on dual channel is actually controlled as HOT WATER. So app, thermostate and button at front would all be wrong.
So its better to.connect backplate wiring to PIN 4, which is controlled as CH.

Just be sure you leave yourself a little message tucked behind the hive receiver explaining what you have done, and why pin 4 not pin 3!!

Good thing with this is that should receiver be reconnected to a old style central heating system without changing it back, electrically its "safe" and will simply not work. No risk of damaging anything.


Again, this is not recommended to try, even though it works. And cannot be liable for any damage or injury caused.

So I've just come across this post in 2025. Had fully functional dual channel hive with a boiler and tanked hot water. Housing have changed the boiler so tank is gone and it's now a combi.
Alot of what I read etc is confusing as!
They decided to leave me 2 days with no stat at all because they weren't sure how to wire in the dual channel and the sparky coming to change my fuse board said he'd do it but that's Wednesday they wanted to leave the boiler in install bypass and me To keep turning the rads on at the boiler each time. Ye I'll just do that at 3am. I was determined.
Installing the dual channel on the combi literally takes 3 wires it's so simple. Yes boiler is direct 240 to the PCB, the programmer sends along the 240. There's not even a common needed. Most people panic thinking where's the common wire. Most boilers 2023 onwards combi now have no common. In the boiler I literally have the open therm connection not being used ATM. Then literally take the cover off and 5 terminals. Earth,Live, neutral, programmer,and heat (heat on and off is literally one wire so it now works on voltage. Hive sends a 240 to the heat boiler starts heating, hive stops sending it boiler stops heating) so with the dual channel it's literally
Live and neutral (they also feed of and feed the boiler permanent supply) no other wires and a single wire in no.4 to the heat terminal that's it. And on the boiler terminals as described in manual, you'll end up with earth ,live, neutral, leave programmer / timer empty as the hive doesn't all, then last Terminal heat to no.4 on the reciever. Turning hot water on and off is redundant so turning it on and off won't do a thing. And hive works exactly as should.
So you don't actually need to bridge any common (UNLESS YOUR SPECIFIC BOILER NEEDS ONE) otherwise it's live,. neutral and no.4 that's it
Logic c30 combi boiler

 

[diydan900]

Looks like a complex solution to a non problem? If the boiler is 230v input then just use the existing L as common as it's already internally wired, or as the switch on 1 is normally closed, cut the link out and use it as common if need be?

Most newer combis don't even have a common anymore. Just had a new combi from a hot water tanked system. Switched fused 240 goes to the hive in L and N, then piggyback that straight to the boiler to feed it the L.and N. Then literally it's no.4 to heat that's it. All my boiler has is 5 terminals. Earth, neutral,live, programmer/timer and heat.
L and N piggybacked from the receiver, then ch 4 to heat and leave programmer empty. Most combis now only have one heat aswell working on voltage. So switch wires not needed anymore just a call for heat wire. Heat on voltage sent. Heat off voltage stops heating turns off .
I have brain damage so struggle alot and most of what's online confused me! Found easiest way to start from the boiler knowing what terminals it's got say it it even needs a common, if it's just a voltage heat or switch. Then you can literally follow it from there.
That's why mine has no common at all literally live, neutral and ch4 from the receiver

 

[ericmark]

23 Dec 2022, I would hope by now all sorted? I look at the base,

and it is rather poor, just too easy to fit wrong unit. I actually have one with the Wiser hub on it, but all my control is 230 volts, so for me not a problem. I have a cylinder with a hot coil, and it can heat DHW using the Nest Gen 3 thermostat, and can't stop it heating the DHW when the CH is running. But the Wiser is single channel, it only works the CH, it is so easy for people to jump to the wrong wiring diagram.

So I am on a C Plan, with two pumps, and two motorised valves both two port, again people look at is and think it is S Plan, they simply count the valves and assume, and get it wrong.

 

[diydan900]

23 Dec 2022, I would hope by now all sorted? I look at the base, View attachment 398916and it is rather poor, just too easy to fit wrong unit. I actually have one with the Wiser hub on it, but all my control is 230 volts, so for me not a problem. I have a cylinder with a hot coil, and it can heat DHW using the Nest Gen 3 thermostat, and can't stop it heating the DHW when the CH is running. But the Wiser is single channel, it only works the CH, it is so easy for people to jump to the wrong wiring diagram.

So I am on a C Plan, with two pumps, and two motorised valves both two port, again people look at is and think it is S Plan, they simply count the valves and assume, and get it wrong.

Definitely. Confused me looking at the diagrams online for combi wiring. In the end I did it myself. Literally grabbed the boiler manual identified the heating block again 5 terminals. L,n,e and heat then programmer. Half hour I was stuck tryna find this stupid common and in the end I did it myself. Ignored the common all together kept the live neutral and earth. Left programmer empty and literally HC NO on no.4 straight to stay terminal bang and done

 

[diydan900]

23 Dec 2022, I would hope by now all sorted? I look at the base, View attachment 398916and it is rather poor, just too easy to fit wrong unit. I actually have one with the Wiser hub on it, but all my control is 230 volts, so for me not a problem. I have a cylinder with a hot coil, and it can heat DHW using the Nest Gen 3 thermostat, and can't stop it heating the DHW when the CH is running. But the Wiser is single channel, it only works the CH, it is so easy for people to jump to the wrong wiring diagram.

So I am on a C Plan, with two pumps, and two motorised valves both two port, again people look at is and think it is S Plan, they simply count the valves and assume, and get it wrong.

What you said about water being on when heat is. Most of the time that's fine. What it'll do is move the diverter valve. So the boiler will fire up regardless of what you've called for then the automatic valve near the tank should divert to tank, radiators or both

 

[ericmark]

I have wondered if the central heating can cool the domestic hot water? I expected as Winter arrived to see the electric used to heat the DHW to drop. Looked a couple of weeks ago, and no real change, but looked today, and yes the electric used is going down. Which is just as well, as very little spare solar at the moment.

 

[diydan900]

I have wondered if the central heating can cool the domestic hot water? I expected as Winter arrived to see the electric used to heat the DHW to drop. Looked a couple of weeks ago, and no real change, but looked today, and yes the electric used is going down. Which is just as well, as very little spare solar at the moment.

Yea it will if it's a system boiler with a tank. As literally the only difference is a valve. So when hot water is called for it does exactly as it would for heating the only difference is it will automatically move the valve to route the heated water to either tank or radiators. Nothing actually changes with the boiler. So then if you call for heat and hot water then valve will open for both meaning the rad water and tank will mix. So temp of the water in one would effect the temp on both. So say heatings on its at flow temp of say 60 as set. You then call for hot water you'll see it rapidly drop because it's introduced the cold tank water to the mix if that makes sense?

 

[ericmark]

Yea it will if it's a system boiler with a tank. As literally the only difference is a valve. So when hot water is called for it does exactly as it would for heating the only difference is it will automatically move the valve to route the heated water to either tank or radiators. Nothing actually changes with the boiler. So then if you call for heat and hot water then valve will open for both meaning the rad water and tank will mix. So temp of the water in one would effect the temp on both. So say heatings on its at flow temp of say 60 as set. You then call for hot water you'll see it rapidly drop because it's introduced the cold tank water to the mix if that makes sense?

Sorry, not really, if I want DHW only, both pumps are off, and both valves are closed, and thermo-syphon circulates the water to the hot coil. If I want CH then the respective valve opens, and the micro switch in the valve works a relay, and one contact in the relay runs the pump, and the other contact the boiler. In fact, one relay missing, on my to-do list, so if the flat thermostat works, it will not run the boiler, only the valve and the pump, the main house thermostat needs to work to fire the boiler. Since flat rarely used, and never used when no one in the main house, this is not a problem.

When hot water is called for, no valve or pump operates. Basic C Plan. But there is no way to turn DHW off when the central heating is running.

So the immersion heater will work, if the tank is cool enough, and either I am exporting electric, or it is summer, and between 00:30 and 05:30 the timed running is not set to work in the winter. The iboost+ runs the immersion heater.

I did not think thermo-syphon would work in reverse, but when the iboost+ display was not showing a reduction in the energy saved, I started to wonder if I had got it wrong.

 

[diydan900]

Sorry, not really, if I want DHW only, both pumps are off, and both valves are closed, and thermo-syphon circulates the water to the hot coil. If I want CH then the respective valve opens, and the micro switch in the valve works a relay, and one contact in the relay runs the pump, and the other contact the boiler. In fact, one relay missing, on my to-do list, so if the flat thermostat works, it will not run the boiler, only the valve and the pump, the main house thermostat needs to work to fire the boiler. Since flat rarely used, and never used when no one in the main house, this is not a problem.

When hot water is called for, no valve or pump operates. Basic C Plan. But there is no way to turn DHW off when the central heating is running.

So the immersion heater will work, if the tank is cool enough, and either I am exporting electric, or it is summer, and between 00:30 and 05:30 the timed running is not set to work in the winter. The iboost+ runs the immersion heater.

I did not think thermo-syphon would work in reverse, but when the iboost+ display was not showing a reduction in the energy saved, I started to wonder if I had got it wrong.

Ah I see. Were stuck with crappy y plans here. That literally do the same thing regardless of what's called just switches water flow with the valve to the rads or tank that's why I replied with that i did just had it changed to a combi due to it being condemned that's how old it was and they do it backwards. Install the new boiler then have to wait for a sparky to wire the stat and programmer so was left on install mode for 3 days with no control just straight on and off. With having the old boiler I was stuck with a dual channel hive kit. That's why I ended up on this thread lol took me five minutes in the end. Ended up spending hours confusing myself the newer combis don't have a common wire so I spent hours tryna figure that out in the end it's literally one single cable from the dual channel hive to the boiler and that's the relay heat on/off

 

[ericmark]

I would think Hive is similar to Wiser. The hub can be linked to up to 9 thermostats, be they wall mounted or part of the TRV. It seems the wall mounted thermostat turns the boiler on/off (up/down if using OpenTherm) and the TRV controls each room. But in my case, only four devices can turn the boiler on/off, but have 10 programmable TRV heads.

The boiler it seems is in good condition in spite of being likely 25 to 30 years old, but oil boilers seem to last better than gas.

 

[diydan900]

I would think Hive is similar to Wiser. The hub can be linked to up to 9 thermostats, be they wall mounted or part of the TRV. It seems the wall mounted thermostat turns the boiler on/off (up/down if using OpenTherm) and the TRV controls each room. But in my case, only four devices can turn the boiler on/off, but have 10 programmable TRV heads.

The boiler it seems is in good condition in spite of being likely 25 to 30 years old, but oil boilers seem to last better than gas.

Wooo hold on, the hive can use opentherm??
As far as I was aware it was simple on off . Boiler on when called for off when at temp.
Opentherm is available using the hive?
Is it a set hive version that's compatible i.e the hive mini etc
Also what reciever is compatible, dual with hot water channel or single combi boiler receiver?

 

[ericmark]

Hive and Wiser both have OpenTherm, the Hive has a little switch to select which mode, can't remember anything I had to switch with Wiser. Since my boiler does not have it, I have not worried about how it is connected.

 

[diydan900]

View attachment 399419Hive and Wiser both have OpenTherm, the Hive has a little switch to select which mode, can't remember anything I had to switch with Wiser. Since my boiler does not have it, I have not worried about how it is connected.

Is that only on the single channel receiver though?

 

[ericmark]

I know with Wiser, the unit is on all three, but instructions says only for use with single channel, which seems odd.

NOTE: OpenTherm is only compatible with combi boilers; therefore, will only work with a single channel receiver.

I have seen a picture of the back and there is a central switch to select on/off or opentherm, if that switch does not exist, then can't be used with OpenTherm.