Danfoss FP715Si to Hive Replacement

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Hello :)
Apologies if this is in the wrong section.

Currently we have a central heating and normal hot water tank system with a Danfoss FP715Si programmer box.
Next week we are getting the Hive smart thermostat system which means I would like to replace the programmer with the new Hive programmer.

Is this a very straightforward replacement? Will the Hive box fit exactly where the old one was and will the wiring be compatible?

We also currently have a ordinary thermostat on the wall, which I assume is connected to the programmer, so when installing the new Hive box is it just a case of leaving the old thermostat not connected to anything?

Thank you.
 
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The FP715Si is wired thus:
FP.JPG


and the Hive Dual Channel version

Hive.JPG


So yes they are wired the same. I usually fit the new backplate that comes with the Hive, so that both are new, but it should fit the existing one.

The old thermostat can't simply be disconnected as this would leave the heating wiring 'open circuit' and it would not operate, so the integrity of the circuit needs to be maintained.

1. Look at the wiring diagram for your make/mode of thermostat that you are removing. If you don't have the instructions for it, a diagram is usually printed inside the lid. This will show which are the two switching wires, and which is the neutral wire. (If there is a neutral present. Not all thermostats need, or have a neutral fitted)

2. Trace the cable back from the thermostat to its point of origin.

3. Take take a photo, or make a note of where the switching wires are connected at their origin.

4. Disconnect all of the wires going to the old thermostat and remove the cable and thermostat. All other wires in the same terminals remain in place.

5. Insert a wire link between the terminals where the two switching wires have just been removed from, so that they are now electrically joined together.
 
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Thank you for responding :)

Glad to hear it should be pretty straightforward swapping the old programmer over to the new Hive one.

The only thing I'm a little confused about now is the old thermostat itself. I always assumed this was just connected to the programmer so thought it would just be a case of disconnecting it from that.

I was also intending on leaving the old thermostat on the wall, so that it could be easily reconnected in the future perhaps for future house occupiers.

The thermostat we currently have is the Danfoss RET230P.
 
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The wiring for the heating presently goes through the room thermostat which acts as a switch. It will turn the heating on & off by opening and closing the circuit. If you simply disconnect it the circuit will be broken which is the same as the heating being 'off' permanently.

You can leave the existing thermostat in place and join the two live wires together inside it instead of tracing them back to their origin. But it's not very professional and not seen as good wiring practice to do so. Redundant equipment should really be disconnected and removed.

If you really want to do a rough job, you could even leave the old thermostat in place and set it to its maximum setting. That will leave the wiring permanently 'on' and stop it interfering with the Hive.

The RET is wired as below:

ret.JPG


So the switching wires will be in terminals (1) ON and (3) COM. These are the two that should be joined together wherever you choose to do it.
 
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When you say "join the two wires together inside it" do you mean just move wire (3) inside the thermostat in to terminal (1) so that both wires are connected in to the same terminal (1)?

While the idea of just setting it to the maximum setting is tempting, that seems very lazy :mrgreen:.
 
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Thank you for your help :)

The Hive arrived today so am going to give it a go :)
 
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Just wanted to update and say that all is working fine and we now have Hive setup :)

Thanks again stem for your help and assistance.
 
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The other day when installing Hive I went for the lazy option and just had our old thermostat set to the maximum to avoid it conflicting with Hive, however that was temporary and I am now going to go for the slightly-less-lazy option of keeping the old thermostat on the wall but making it basically irrelevant by moving the wires inside it as instructed above.

I've taken the front cover off and just wanted to confirm once again that all I need to do is simply move the wire on the far right (3/COM) over in to (1/ON) with the other wire that's already in there. And assume that I leave all the other wires as they are.

IMG_0027.JPG
 
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Yep, that would do it, or it might be less fiddly to discard the link and move the black wire from 'on' to 'L' with the brown wire. Electrically it achieves the same thing.

Ideally the black wire presently in the 'on' terminal should have a red (or brown) sleeve on it to identify that it is being used as a live wire.
 
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The other option as you say is to remove the link (the red wire currently going from L to 3?) completely and then just move the black wire in 1/ON over to L, so then there would be no wires in 1/2/3?

That sounds tidier and less fiddly as you say, and might be the better option out of the two. I just again wanted to confirm I've got that right before doing it.

As you can probably tell I'm not overly confident (though very keen on learning as I go) with wiring :D
 
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The other option as you say is to remove the link (the red wire currently going from L to 3?) completely and then just move the black wire in 1/ON over to L, so then there would be no wires in 1/2/3?

Yes that's it. Whatever way you do it, the black wire will be electrically connected to the L somehow, either directly or via the link.
 
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All done :) Thanks again.

Now it has no affect on the boiler wherever the old thermostat is set on :)

IMG_0028.JPG
 
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