Replace Wengart (or generic) Thermostat with Tado Smart Wired

[JamesFMB]

Hi there,

I'd like to swap my existing wired thermostat with a Tado Wired, but I'm not sure what configuration I need. My boiler is an Ideal ESP 1 30 which supports Opentherm modulating, so I guessed it would be 'digital'.

I've attached a picture of what I currently have on the Wengart. This Thermostat uses 3x inputs, but the Tado digital would be just 2x.

Any help would be gratefully received

Thanks

 

[Stuckinarut]

Sounds like the Tado is battery operated, so only live and switched required. Safely terminating the neutral conductor in a chick block/terminal strip connector or Wago/similar. Opening up that boiler requires a critical safety check afterwards as it forms part of the combustion circuit, if you wanted to use opentherm.

 

[ericmark]

Digital = on/off, analogue = up/down, so OpenTherm is analogue, but you are showing an on/off digital thermostat.

The important wires are 2 and 4, the neutral is not required with some thermostats, but Tado withdrew there OpenTherm in the UK, it is made for Europe, but not readily available in the UK. And would require new wires to the boiler.

The repeated switch of a boiler on/off can reduce the efficiency of the boiler, so the basic idea is to use a wall thermostat to turn boiler off in warm weather, but the control of the output is done by the analogue slowly opening and closing of the TRV's. So the easy way is to have a hub of some sort, which connects to the TRV heads, to tell boiler when no longer required.

There are a host of systems which use this method, Honeywell EvoHome, Drayton Wiser, Hive, and I think Tado, some also have OpenTherm options, some like Hive don't, and there are some like Nest which has OpenTherm, but does not connect to TRV heads, so really only any good with hot air central heating or open plan.

In the main linked programmable TRV heads are expensive, so common only to use them in key rooms, with cheaper non linked in other rooms, but since the TRV head is the important bit, we need to decide which best suits us, then get a wall thermostat or hub to work with them.

And I will admit, I got it wrong, I bought 4 Energenie MiHome TRV heads which claimed they worked with Nest, but on then getting Nest, found they did not work with Nest, and even if they had, worked the wrong way around, Nest should have set the TRV head to same setting as Nest, but what is wanted is for TRV head to set the wall thermostat or hub, not the other way around.

So I now have 9 programmable TRV heads, non which connect to either Nest or the Wiser hubs, I will slowly replace existing with Wiser TRV heads, now I have Wiser I can expand, but my boiler does not have OpenTherm, and it does not even modulate, being an oil boiler, so although both Wiser and Nest have the option of using OpenTherm, I will not be using it.

 

[JamesFMB]

Sounds like the Tado is battery operated, so only live and switched required. Safely terminating the neutral conductor in a chick block/terminal strip connector or Wago/similar. Opening up that boiler requires a critical safety check afterwards as it forms part of the combustion circuit, if you wanted to use opentherm.

Hi Stucinarut, thanks for the reply. Do I need to enable Opentherm modulating on the boiler? Would that require rewiring? This is my current wiring setup, thank you

 

[JamesFMB]

Digital = on/off, analogue = up/down, so OpenTherm is analogue, but you are showing an on/off digital thermostat.

The important wires are 2 and 4, the neutral is not required with some thermostats, but Tado withdrew there OpenTherm in the UK, it is made for Europe, but not readily available in the UK. And would require new wires to the boiler.

The repeated switch of a boiler on/off can reduce the efficiency of the boiler, so the basic idea is to use a wall thermostat to turn boiler off in warm weather, but the control of the output is done by the analogue slowly opening and closing of the TRV's. So the easy way is to have a hub of some sort, which connects to the TRV heads, to tell boiler when no longer required.

There are a host of systems which use this method, Honeywell EvoHome, Drayton Wiser, Hive, and I think Tado, some also have OpenTherm options, some like Hive don't, and there are some like Nest which has OpenTherm, but does not connect to TRV heads, so really only any good with hot air central heating or open plan.

In the main linked programmable TRV heads are expensive, so common only to use them in key rooms, with cheaper non linked in other rooms, but since the TRV head is the important bit, we need to decide which best suits us, then get a wall thermostat or hub to work with them.

And I will admit, I got it wrong, I bought 4 Energenie MiHome TRV heads which claimed they worked with Nest, but on then getting Nest, found they did not work with Nest, and even if they had, worked the wrong way around, Nest should have set the TRV head to same setting as Nest, but what is wanted is for TRV head to set the wall thermostat or hub, not the other way around.

So I now have 9 programmable TRV heads, non which connect to either Nest or the Wiser hubs, I will slowly replace existing with Wiser TRV heads, now I have Wiser I can expand, but my boiler does not have OpenTherm, and it does not even modulate, being an oil boiler, so although both Wiser and Nest have the option of using OpenTherm, I will not be using it.

Hi Ericmark, thanks for your reply, Tado call it a digital connection for Opentherm, I've read somewhere that this is the correct connection for Opentherm, what do you think?

 

[ericmark]

Hi Ericmark, Tado call it a digital connection for Opentherm

How odd, although I suppose 256 steps is technically digital, but most PLC's I have worked on call that analogue, even if analogue is technically infinitely variable.

 

[Stuckinarut]

Hi Stucinarut, thanks for the reply. Do I need to enable Opentherm modulating on the boiler? Would that require rewiring? This is my current wiring setup, thank you

No it’s not to be enabled as such, the wiring would go to the opentherm connections on the pcb where the purple link is currently. So a small repair would be needed as it’s extra low voltage, approx 5-7 volts. Please bear in mind what I said about removing the boiler cover.