Hi does anyone know how the eph cp4m thermostat wires to the Tado v3+

Dizzie41

Does anyone know how this wires to the tado v3+

policywonk

@Dizzie41

Will explain. Whoever installed that thermostat was aware that your boiler can be controlled with Opentherm, a digital system which enables the boiler to run efficiently.

They then strangely decided to wire the boiler in dumb on-off mode instead.

So, if you can wait, please do, because if you could tell Tado that this boiler can be wired in Opentherm mode it will help you get the right instructions to check the wiring at the boiler, and at the thermostat and over a year save money because in this mode the boiler runs more efficiently.

The alternative is if you don't have time, do you know an electrician who can study the installation manual for the boiler and make the changes for you? The guide is here:
https://www.manualslib.com/manual/2905495/Ideal-Heating-Logic-Heat2-H12.html?page=30#manual
Look at page 30.

If not and you want to press ahead, Tados are versatile. With that map given above it should work and use the boiler in dumb mode as before. Then, later, do consider making the time in the next few months if you can to find out how to change the connections between the thermostat and the boiler and what to change in the settings in your app, so that you can operate that boiler more efficiently. It will save on your gas bill.

policywonk

Am a little lost. This seems to be a boiler that runs with a hot water tank in the building.
1. Is this a combi or one which also drives a hot water tank?
2. Have you contacted tado to get instructions?
We can help identify the wire swap, but that may not be entirely effective or correct without more information.
Meanwhile, from the pictures this is how one would transfer the wires:
1. N (neutral) to P1 on the Tado
2. L (live) to COM on the Tado
3. pin 1 (com), that loop to L is discarded
4. pin 4 (on) to NO in the Tado
Look at this guide https://cdn.brandfolder.io/607DGEMS/as/7k4rssnm8hbmr6mjf94qmck/104210-DIGITAL-ST01IB01-INSTALLER_MANUAL-TA-EN-00-V3.pdf

Go to page 4, implement the setup designed for R01.
However, this is important, get Tado to confirm this via the app before you turn the power back on!

Dizzie41

Hi, I have not long moved into a new build and it’s not a combo boiler. I have a separate thermostat for the hot water and I wasn’t going to do anything with that one. I’ve contacted tado and they have said it takes up to 2 days for a reply so thought I would try on here.

Dizzie41

Thanks for your help

policywonk

Would you double check on the wiring that triggers the boiler to supply the HW tank? Is there another timer involved supplying heat to the tank when it's thermostat calls for it?
Additional suggestion: do get Ideal to recommend an electrician who would amend the wiring to enable your home to run in opentherm with Tado as the control environment.