Changing Danfoss TP9000/5000 to Drayton Wiser Kit 3

[stem]

Usually the motorised valves are physically next to each other, so if you were to connect the upstairs valve to the downstairs valve wiring terminals they will both open together.

Just a word of caution though. As you already have two heating zones, I'm assuming your property is fairly new (Post 2010) as the two zone arrangement is now a requirement of Part L of the building regulations. So, converting it to one zone would put it in contravention of the regulations. Although no one will come and inspect of course, but you may find that should you sell the property and the survey highlights it, you may have to reinstate it at your cost. Also, you will likely find that the upstairs room where the room thermostat is located doesn't have a TRV on the radiator, which may mean that that room will get overheated without a TRV if the control provided by the room thermostat was removed.

 

[mailliw]

So you'd recommend connecting the valves and replace the TP9000 with the Wiser, instead of wiring the Wiser directly to the boiler? Your advice about the building regs is excellent, much appreciated. We've just bought the place, so suspect we'll be here a while, but I'll keep tabs on what I change so I can reverse it. Thanks for the warning.

What though should I do with the redundant TP5000, just disconnect?

 

[stem]

So you'd recommend connecting the valves

No I wouldn't "recommend" it, I was answering your question about how to turn a two zone system into a single zone. Personally, I would do it properly and keep the two zones. The idea behind the building regs introducing the two zones is to save energy by allowing you to operate the heating more efficiently. And as the second zone is already there I wouldn't remove it.

instead of wiring the Wiser directly to the boiler?

The Wiser is not be wired to the boiler anyway when connected to a system that has motorised zone valves.

The Wiser is wired to the motorised valves, which it will open and close as required. Inside each of the motorised valves is a small switch that controls the boiler. So it's the motorised valves that are wired to the boiler and not the Wiser. That's how it will be with the Danfoss presently.

What though should I do with the redundant TP5000, just disconnect?

That's up to you. It can be left in place in case you do reinstate the two zones in the future, or if you want to remove it and isolate the wiring to make it safe you can do that too.

 

[mailliw]

Thanks, that makes sense. What I can't understand is the wiring for the old TP5000. The TP9000 sits in a cupboard near the Danfoss WB12 wiring, so the Wiser hub will replace the 9000 fine, but the TP5000 is two floors up. If I remove the 5000, how do I switch that valve on and off without connecting the valves together in the WB12?

 

[stem]

There's another thread where the OP wanted to do the same thing as you. You can read it here.