Can I replace Honeywell BDR91 receiver with a Tado wired thermostat?
Hello,
I purchased the Tado V3+ wired thermostat with the hope I could use it as replacement of my Honeywell BRD91 receiver which simply turns the heating on and off.
Below the current setup of the BRD91 and how I tried to connect the Tado wired thermostat with no luck.
What did I do wrong?
Answers
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I don’t see why this wouldn’t work except that the bdr91 isn’t a thermostat so you’re not doing a like for like replacement. I replaced mine with a Tado extension kit (now known as wireless receiver) which worked fine. I’m assuming you have a combi boiler which the bdr 91 was wired into?0
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Hi @johnnyp78, thanks for your reply. That's right, for my combi boiler I currently use a Honeywell CMS927 wireless thermostat connected to the BRD91 receiver. Should I then buy the Tado wireless receiver to recreate the same setup I have now by converting the wired Tado thermostat into a wireless one?
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I have strong doubts that it's an SL system, due to the spindly wires.
I'd suggest looking at the type of boiler and configuring your Tado for wiring appropriate for the boiler type.
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Thanks @Montage, the boiler I have is this one: AWB ThermoMaster 2HR (28.02 WT). Do you think I can still use the Tado wired without receiver?
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Yes, I do. I haven’t read the document but can see the where it originates. Boilers in NL usually have to work with OpenTherm, so you should probably connect for that. All of which is fine on the wired Tado. Burn less gas, not more money and skip wireless.
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I don’t want to confuse things but the bdr91 is a relay system (in the uk) at least. But as @Montage says, if you can connect via Opentherm, do that.0
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I believe it is. How it is connected at the boiler will be interesting.
The thing with OpenTherm is that the standard is backward compatible. Meaning if you short the pair of wires, the boiler will fire.
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Thanks both for your comments.
Assuming I can connect via OpenTherm, how should I then connect the spindly wires?
BRD91 "A" --> TADO "-"
BRD91 "B" --> TADO "+"
Would this work or will I fire the boiler? :)
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You should verify they are connected ok at the boiler (for OpenTherm).
Then attach to + and - and it doesn’t matter which way round. (No polarity)
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As @montage said, look for the Opentherm connections on the boiler. Sometimes they’re in an orange block.1
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I attached the spindly wires to + and - and the heating turns on. The problem is that I can't switch it off with the app nor with the Tado itself as it looks like it's always on. Would the use of a wireless receiver solve this issue? I guess it would work as my current Honeywell wireless thermostat which simply switches on/off the power of the BDR91.
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No, you need to fix the problem, not buy more stuff.
Have you configured the Tado for OpenTherm?
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Ok I'll try, thanks!
Yes, I followed the steps on pages 8-11 from the attached manual but the Tado doesn't make any on/off sounds when D01 is selected (page 10).
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It ought to be silent for OpenTherm or any digital mode.
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This is how the wiring connection to the boiler looks like.
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I think you need to be looking on the other side of that metal sheet.0
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Yes better to do it tomorrow with the sunlight, thanks.
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This is the inside of thw boiler. Do you know whether the Tado config. code I selected (D01) is the right one?
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I am completely baffled by this. Where’s the pcb? Does it even have one?0
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This one maybe? Just guessing.
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I assume this means red/white and blue/white wires for OpenTherm. They might be in the room stat block at moment
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It's a bit too advanced for me, but thanks a lot to both of you for the effort. I thought I could simply replace the BDR91 and the only wireless thermostat connected to it. I'll probably have to contact a technician :/
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It usually is a fairly simple job on uk boilers, where the opentherm connections are clearly marked on the pcb. If I had a boiler that looked like that I’d be asking a professional for help too0
