OpenTherm Y-Plan

BigChin1 · 7 Dec 2018 at 15:51

I have a typical y-plan heating setup with hot water cylinder, 3-port valve, and pump. My boiler is being replaced with an Ideal Logic+ 15 Heat controlled by an existing Tado Extension Kit / Smart Thermostat. This is currently connected using the 230V on/off method.

The Logic+ has OpenTherm connections and was wondering if this can work with a y-plan setup. Any heating geeks in here that have done something similar?

robj20 · 7 Dec 2018 at 16:09

Yes it can work all opentherm is, is instead of an on off signal it requests a flow temperature instead.

On my evohome you can see how the controller calculates it each room has a percentage heat load it then adds these up and then requests a flow temp to satisfy this heat load.

BigChin1 · 10 Dec 2018 at 14:04

Thanks for the reply. I asked tado to send instructions on how to achieve this but their response is as follows:

"Unfortunately, you cannot use the OpenTherm connection of your boiler if you have a Y-plan setup, it is only possible if you use it for heating only."

Might be one of those 'technically possible' but 'not supported' scenarios. Shame. Ideal offer a Weather Compensation Kit to measure outside air tempeature and modulate the boiler accordingly, may look into this instead.

robj20 · 10 Dec 2018 at 14:19

Must be a tado thing then.