Replacing ESi ESRTP4RF+ with tado Wireless Receiver X on Ideal Logic+ Combi 30

[Rizzlepixs]

Hi all,


I’m looking for some advice on replacing my existing wireless thermostat receiver with a tado Wireless Receiver X, and I’m hoping someone familiar with this boiler and receiver can help.


My setup:

• Boiler: Ideal Logic+ Combi 30
• Boiler GC number: 47-348-66
• Existing receiver: ESi ESRTP4RF+
• New thermostat/receiver: tado Wireless Smart Thermostat X Starter Kit (UK version)
• The existing receiver is hardwired and powered via a wall-mounted isolator switch.

Current ESi receiver wiring:


The terminals are currently connected as follows:

• N: two blue wires
• L: two brown wires
• Terminal 1 (COM): one blue wire
• Terminal 2 (NO): one brown wire
• Terminals 3, 4, 5 and 6 are empty
• Earth wires are connected to the earth terminal.

The ESi receiver’s terminals 5 and 6, which are for OpenTherm, aren’t being used.


The tado app recognises the ESi ESRTP4RF+ but then tells me an additional two-core power supply cable is required. Its instructions don’t clearly explain how to transfer the existing hardwired supply and heating control connections to the tado receiver.


My questions are:

1. Is this boiler and receiver setup using 230 V switched-live relay control, or potential-free relay control?
2. Can the existing hardwired supply and wall isolator be reused to power the tado receiver, rather than installing a separate plug-in power supply?
3. Which tado terminals should the existing common and normally-open heating control connections go to?
4. Does the tado receiver need an L-to-CH COM link for this particular setup, or would that be incorrect?
5. Has anyone installed a tado Wireless Receiver X on this exact boiler, ideally replacing the same ESi receiver? Photos or a wiring diagram showing the boiler-side connections would be particularly helpful.

I’ve found the boiler installation manual, which includes diagrams for external room thermostats and programmers, but I don’t want to assume the original installer followed a particular diagram without verifying the actual connections.


I’m happy to provide photos of the receiver terminals and wiring, and any advice would be appreciated.


Thanks!

 

[CountryFan]

If no wires are linked, then just transfer as is:

X2 blue from N to N
X2 Brown L to L
Com to Com
NO to No and park earth/cpc

 

[ericmark]

I started by looking for the manual on line, linked to what I found and it does seem the boiler is both OpenTherm enabled and can have outside sensors.

Any extra low voltage cable should be run independent to low voltage (230 AC) as to if really required, I don't know, in fact how much controls in general reduce or increase running costs, is something which can be debated until the cows come home.

So basic idea, the boiler heating the water, the pump circulates the water, and the boiler measures the return water temperature to decide how much it should modulate the output, the TRV heads control the flow in an analogue way and as they close the by-pass valve opens, so the return water is a very good indication of how much the boiler needs modulating (turning down output) but for this to work, the boiler must not be turned off with an outside control too often, as each time it is turned off and on again, the boiler starts from scratch working out the output required.

So the ideal method is instead of using return water, to use an analogue hub, and electronics instead of return water temperature, this allows an even lower return water temperature, and even more energy gained from the latent heat of the flue gases.

In real life, we tend to use a mixture, but the important point, is the hub (which may be combined with the thermostat in some cases) will only turn off the boiler, when it is no longer required, so for the boiler to turn off say twice a day, when we leave the house and when we go to bed is OK, but turning off and on 10 times a day is bad.

But even with an on/off control, when the hub is linked to electronic TRV heads, it is likely all day at least one head will be demanding heat, so the boiler does not switch off, each rooms heat is controlled by the TRV.

However, histrionically we had done things which today hinder the control, from the fitting of on/off zone valves, which with electronic TRV heads are no longer required, or putting radiators on outside walls, so the TRV head until a thermal flow is established is not measuring the true temperature of the room. So some makes of TRV head, produce thermostats or sensors which can monitor the temperature on an internal wall.

But all this control costs money, so we tend to use near enough engineering, and the debate is how far to go with the control?

So on the cheap, we fit an OpenTherm thermostat to one room in the house, and trust to the Lord the other rooms will be warm enough, use of the lock shield valve and mechanical TRV heads help, but it depends where the OpenTherm thermostat is fitted, my house (not OpenTherm) the thermostat was in the hall, and no real option to move it when hard wired, and the problem was the hall cooled to slowly, so all other rooms cold while waiting for hall to cool, and if doors open or closed, affected how the system worked, so forced to go to wireless, and have a thermostat in the living room as well, in parallel so if wireless fails (discharged battery) still get some heat.

So with a single temperature sensing system, the OpenTherm will work far better, but, with a multi-temperature sensing system i.e. all electronic linked TRV heads, because one head will likely always be calling for heat, so the hub will not be turning on off all the time, OpenTherm has less of a benefit.

So this is why some sing the praises of OpenTherm and others don't, it does not help as much with an all linked TRV head system, still helps, but not to same extent.

So my near enough, is 10 electronic TRV heads, but only 1 is linked, and 2 wall thermostats, in parallel. There is no right and wrong, they will all work, but some will allow the boiler to gain more latent heat to others.

I look at the minium output of 4.9 kW which is impressive, but in my living room I could not sink that much heat from my radiators, so the boiler would still need to cycle to heat one room only, at least if the boiler insulates the cycle (not thermostat) it restarts at minium output, but this time of year, in general boilers are not suited to the demand, as winter comes they work better, but as to heating house at the moment, I use an oil filled radiators as so much energy lost in pipework etc.

Oh what a tangled web we weave. But what I am saying is, as far as OpenTherm goes, much depends on how many linked TRV heads are used.

 

[Rizzlepixs]

If no wires are linked, then just transfer as is:

X2 blue from N to N
X2 Brown L to L
Com to Com
NO to No and park earth/cpc

Thanks! So no need for a link between L and CH COM in this setup then?

 

[CountryFan]

Thanks! So no need for a link between L and CH COM in this setup then?

I don’t think so, unless the Esi has one?

 

[Rizzlepixs]

I don’t think so, unless the Esi has one?

Nah it doesn’t, just wanted to make sure it wasn’t something the Tado would need.

 

[Rizzlepixs]

Can confirm a like for like swap worked I now have heat just as the cold rolls in!

 

[CountryFan]

Can confirm a like for like swap worked I now have heat just as the cold rolls in!

Great. To quote Hannibal Smith, I love it when a plan comes together