Danfoss 5000si dual zone to Hive multizone

[StefabB]

Hi,
Hopefully you can help. I am looking to change 2x Danfoss 5000si to Hive active heating. I bought 2x as I have a downstairs one that control.the entire floor and one in the master bedroom to control the 1st floor.
When looking at the boiler and the danfoss I can see I only have 2x wires connected with a grey one left dangling. Boiler Ideal Logic 35 combi espi boiler.
Can you recommend how to connect these cables? I am guessing it should be like for like swap but I can't see any blue (N) cable at danfoss. Attached pictures from boiler and from Danfoss.

Thank you in advance!
Stefan

 

[ericmark]

As far as I am aware EPH do thermostats which can be set as master and slave, but they are about the only ones. Think up to 10 zones can be set out.

Personally I would use the TRV heads to set zones, not zone valves, as they work better it seems.

The originally thermostat seems odd, as just on/off, where that boiler is opentherm (up/down) I suppose you could use a on/off thermostat, but once you use a thermostat which can be linked to TRV heads it seems pointless to use two.

Hive is not opentherm so would not use with an opentherm boiler, but it will clearly work, but not in the best way, so first thing is sit back and decide what you want.

I am a fine one to talk, I fitted Nest Gen 3 which did not really work in this house, maybe that's why I am pointing out likely for you Hive not best option. But much depends on house design, had my hall cooled down faster Nest would have likely worked better.

Today we look at saving money spent to run the central heating, and the TRV in the main is the device which allows room by room control, so what we want is the TRV to be able to control the boiler, they can easy turn boiler output down, this is done with the return water temperature and the by-pass valves, but turning the boiler on or off not as easy.

So we use linked TRV heads, which is why my Nest is useless, it does not link to TRV heads, Hive however does, to an extent anyway, it has a upper limit of 22ºC and if the wall thermostat reaches this, then the demand for heat from the TRV heads is ignored, so Hive needs to be in a room normally kept cool.

One could have a wall thermostat in every room, this is basic idea of the under floor heating units, but where we have TRV's we normally don't need hard wired wall thermostats in every room. The important thing is the wall thermostat turns on when any room is under required temperature, this house it is in the hall, the idea is with doors left open for rooms in use, the hall will be an average of the house temperature, however in this house hall cools too slow.

So looking at Honeywell EvoHome, Drayton Wiser, Tado, and others where the wall thermostat is really a hub collecting info from the TRV's. Nest has Opentherm built in, but EvoHome and Wiser it is an add on module, Tado you have to select correct version, EPH as said works with motorised valves rather than TRV's but still is OpenTherm.

Since my house is oil heated I am not the best to ask as to advantage of OpenTherm.

 

[CBW]

I think you mean neutral wires as opposed to blue, as they can be grey, but colours in a heating system mean diddly swat. You need to wire the receivers near the wiring center, not the boiler. Another diyer who thinks they can just remove the boiler cover without checking for safety afterwards.

 

[StefabB]

I think you mean neutral wires as opposed to blue, as they can be grey, but colours in a heating system mean diddly swat. You need to wire the receivers near the wiring center, not the boiler. Another diyer who thinks they can just remove the boiler cover without checking for safety afterwards.

Yes, that is neutral. I do have my annual boiler maintenance and gas safety annual check scheduled in but wanted to understand what/how to mount it and if I need to quote that in or do it myself. Thanks for your reply, but it's more critic than to offer guidance. If you have anything more specific, I'd be glad to hear it.

 

[StefabB]

As far as I am aware EPH do thermostats which can be set as master and slave, but they are about the only ones. Think up to 10 zones can be set out.

Personally I would use the TRV heads to set zones, not zone valves, as they work better it seems.

The originally thermostat seems odd, as just on/off, where that boiler is opentherm (up/down) I suppose you could use a on/off thermostat, but once you use a thermostat which can be linked to TRV heads it seems pointless to use two.

Hive is not opentherm so would not use with an opentherm boiler, but it will clearly work, but not in the best way, so first thing is sit back and decide what you want.

I am a fine one to talk, I fitted Nest Gen 3 which did not really work in this house, maybe that's why I am pointing out likely for you Hive not best option. But much depends on house design, had my hall cooled down faster Nest would have likely worked better.

Today we look at saving money spent to run the central heating, and the TRV in the main is the device which allows room by room control, so what we want is the TRV to be able to control the boiler, they can easy turn boiler output down, this is done with the return water temperature and the by-pass valves, but turning the boiler on or off not as easy.

So we use linked TRV heads, which is why my Nest is useless, it does not link to TRV heads, Hive however does, to an extent anyway, it has a upper limit of 22ºC and if the wall thermostat reaches this, then the demand for heat from the TRV heads is ignored, so Hive needs to be in a room normally kept cool.

One could have a wall thermostat in every room, this is basic idea of the under floor heating units, but where we have TRV's we normally don't need hard wired wall thermostats in every room. The important thing is the wall thermostat turns on when any room is under required temperature, this house it is in the hall, the idea is with doors left open for rooms in use, the hall will be an average of the house temperature, however in this house hall cools too slow.

So looking at Honeywell EvoHome, Drayton Wiser, Tado, and others where the wall thermostat is really a hub collecting info from the TRV's. Nest has Opentherm built in, but EvoHome and Wiser it is an add on module, Tado you have to select correct version, EPH as said works with motorised valves rather than TRV's but still is OpenTherm.

Since my house is oil heated I am not the best to ask as to advantage of OpenTherm.

Thanks, OT is new to me but you actually made me re-think my decision to look for a Nest instead of Hive. My question is, does OT require new wiring or can it use the existing? that's going to weigh into the decision as I am not going to start running new cables.

 

[ericmark]

I would say it will need new cables, but very short from hub to boiler. However as to if OpenTherm really helps depends on the set up and boiler.

My mothers house had a gas Worcester Bosch boiler, which does not support OpenTherm, all is done using the return water temperature, but there is a flaw, the boiler without a wall thermostat would never switch fully off, it would cycle on/off, the anti-cycle software would reduce how often the boiler fires up to try, but it needs some method to switch it off when whole house warm.

If the boiler is switched off, and then back on, it will switch on at maximum output with some boilers, although not all, so the less the boiler is switched on/off the better. Also the boiler is controlled by the by-pass valve in or near the boiler opening so hot water is returned fast, having a bathroom towel rail or the radiator where the thermostat is without a TRV can upset some boilers.

The installers used this

thermostat which to stop hysteresis starts switching off/on before it reaches target to stop it over shooting, and the thermostat was placed in the hall, with no TRV in the hall, so every time my mother went out the hall would cool down front doors tends to stay open a long time when in a wheel chair, and if the lock shield set so hall temperature would recover then hall heated up too quick when door not open, and made rest of house cool.

Adding a TRV to hall radiator transformed whole house, as then the hall could recover fast until at around 16ºC then slow up before reaching 19ºC at what the wall thermostat was set to. I am not saying this will work with every house, but it did with hers.

In fact it does not work with this house, hall cools too slowly, I can set heat up speed with the lock shield valve, but no way to control cool down speed.

Some times the simple thermostat works better, but if you want a Eco and Comfort setting, no good doing it with just the wall thermostat, it needs matching with the TRV. And if the radiator heats up too fast, the TRV will not have enough time to close, and so start a hysteresis.

I used these in mothers house, they worked well, but the anti-hysteresis software was OTT, so set to 22ºC at 7 am and 20ºC at 8 am or it would have been 10 am before room at 20ºC.

This house I have also used these which were far cheaper I paid £15 each in 2019, so have 4 of the Energenie and 5 of the eQ-3 the latter seem to work better than the more expensive wifi versions, non link to wall thermostat.

I think I may have been better with Drayton Wiser, the TRV algorithms are better, designed to work out how long it takes to heat the room, but I wanted CH and DHW control in main house hard wired, and Nest Gen 3 did this with the two existing wires, and I thought when I fitted it that it would work with Energenie, seems Nest withdrew support.

However the TRV is king, the wall thermostat is only there to stop the boiler cycling, once the lock shields are set to stop any hysteresis even the mechanical TRV's do work spot on.

 

[CBW]

Thanks for your reply, but it's more critic than to offer guidance. If you have anything more specific, I'd be glad to hear it.

I offered guidance, you must have missed it:

You need to wire the receivers near the wiring center​