Firebird 120 Combi boiler with Honeywell Home T6R smart thermostat

[macmagician]

I have a Firebird 120 Combi boiler and was recommended a Honeywell Home T6R smart thermostat by the local plumbing supplier so that I can fully control the boiler with a smart app and my Apple HomeKit.

The point of getting this smart thermostat was so that I may turn on and off BOTH the central heating and hot water systems wirelessly or using the timer in the smart thermostat. However, looking into how one is expected to use these smart thermostats with a combi boiler, it seems that the norm is that the hot water is just left on permanently, and the only system that is connected to the smart thermostat is the central heating. This is not what I wanted at all. The hot water system in the boiler can be turned on and off at the boiler, and the boilers internal hot water timer can be used to do this or overridden to constant on, or constant off. The central heating system in the boiler can also be turned on and off at the boiler, and the boilers internal central heating timer can be used to do this or overridden to constant on, or constant off. Like this:

As the hot water system uses and wastes oil (eg: while we are sleeping) so long as the system is switched on (as the system keeps a small amount of water hot all the time it is on), I want the smart thermostat to also turn on and off the hot water system with its timer, and allow me to override this switching using the smart thermostat app or my Apple HomeKit.

I then also want the smart thermostat to allow smart control of the central heating system as well.

Is this possible or would I need to return the smart thermostat because it cannot do what I want?

I attach a photo of the Honeywell Home T6R smart thermostat wiring diagram which shows the wiring for combo boilers as just using terminals A and B for central heating, with no provision for hot water switching using terminals D and E (which I want to use to turn on and off the hot water).

I do hope someone can help, and thank you.

 

[Exedon]

Assuming you have a 2 channel reciver you need to take the hot water switched live feed from terminal E to the boiler to feed hot water.
If you can post a picture of your boilers internal wiring diagram can then advise further.
I note honeywell only mention gas boilers on there instructions. I would make absolutely certain the stat is OK for oil boilers.

 

[macmagician]

Thank you so much @Exedon.

This is the wiring diagram taken from the boilers manual.

In addition from receiving assurance from the plumbers suppliers, I have also read online that the T6R Smart Thermostat is suitable for most water-based heating systems, including combination and system boilers, either gas or oil-fired.

Assuming I can establish it may be used to control hot water as well as heating, I will take a photo of the actual control box connections and upload here to make 100% sure I am wiring everything up to the correct terminals. I am fairly confident that I have a handle on what goes where, but want to make darn sure I am correct.

Thanks again, you're a star!

 

[Exedon]

In essence you need to find the switched live from both existing time controls disconnect them and feed from your new receiver box.
If there is a existing room thermostat that goes back to boiler control panel disconnect that as well (may require a link installing)

 

[macmagician]

@Exedon - that would be the Hot Water and Heating timer terminals in the far top right of the diagram then? Also, shown to the right of the Mains, bottom right?

 

[Exedon]

That's the ones multimeter to check first!

 

[macmagician]

@Exedon, thank you, you're exceptionally helpful! Just to clarify, there is no existing room thermostat to worry about.

So, assuming I get 230v on multimeter from A and B, as below:

I would then need to connect A from the boiler (above) to B in the receiver box (below) and B from the boiler (above) to E in the receiver box (below), and then in the receiver box link the second L terminal (below) to A (below) and D (below)?

I hope that's correct so I can stop pestering?

 

[snb1]

Which honeywell t6 do you have. A t6r is a single channel thermostat. For hot water control as well you need the t6rw.

 

[snb1]

Honeywell stats are suitable for gas, oil renewables etc

 

[macmagician]

Hi @snb1, I have this T6R, which says "with optional Hot Water Control" and has a shower icon button (water) and a flame icon button (heating) on the receiver:

 

[snb1]

If it has that then you can just wire it in to control both heating and hot water.
You will need to reset the programmer and enable it for both heating and hot water

 

[macmagician]

Thank you so much @snb1! In your learned opinion, are you able to confirm that the way I think it should be wired (see above) is correct?

@Exedon, thank you, you're exceptionally helpful! Just to clarify, there is no existing room thermostat to worry about.

So, assuming I get 230v on multimeter from A and B, as below:

View attachment 325480

I would then need to connect A from the boiler (above) to B in the receiver box (below) and B from the boiler (above) to E in the receiver box (below), and then in the receiver box link the second L terminal (below) to A (below) and D (below)?

View attachment 325481

I hope that's correct so I can stop pestering?

 

[snb1]

Yes your wiring would be correct