Sonoff wifi smart switch upgrade for Honeywell R6660D

[KB009]

Hi there, I have been wanting to upgrade my old Honeywell R6660D.

Ok so I've wired the Sonoff plug and it works fine to turn on and off. But if I leave the Honeywell wireless controller it needs to be reset each time as the power goes off.

I assume the Honeywell controller is just a smart switch. If I wire in another sonoff wireless switch will this be able to control?

Otherwise I have to reset the wifi controller each time. I guess if I can wire another sonoff I can control the heat pump to circulate for a few minutes after I turn the system off.

Any help appreciated

 

[stem]

So, if I understand you correctly, You have a wireless Honeywell thermostat and a R6660D relay box now powered via a Sonoff switch. When the Sonoff switches the relay box 'off' and then back 'on' it has to be reset.

If that's correct and assuming that the R6660D is switching 230V for the heating via terminals A & B, then one solution might be be to wire up the R6660D relay box N and L to a permanent 230V supply (i.e. not via the Sonoff) and just connect the switched live from the Sonoff to terminals A & B

That way the relay box is kept permanently powered to won't need to be reset, and the Sonoff will only turn the heating 'on' and 'off' in conjunction with the Honeywell.

I'm puzzled that your profile shows you as being in the UK, but your photo shows a European plug, and I have no idea of the current rating of a Sonoff plug, and whether it's up to the duty or not. [I've only ever installed a 4CHPro on some lighting circuits]

The whole installation (Heating system / Sonoff / R6660D) should be fed from the same circuit and via the same isolator, so that one switch isolates it all for maintenance.

 

[KB009]

Thank you stem, Yes, I am in France at the moment.

The Sonoff is a 10amp switch so no issues there. ( the phone app is great). This is a somewhat modified (not by me) system. It was an upgraded burner and the technician wired in the Honeywell. But with limited range the wireless thermostat isnt where we sit. The Sonoff connected to a temperature monitor can be set to where we sit.
I assume the current setup the Honeywell controls the heat pump that circulates the fluid through the radiators. So hence there is no circulation before the controller is reset.
So I assume that there is power coming from the burner and the honeywell is just wired in to control the heat-pump. In theory I should be able to just connect these outputs together and it would revert the system back??? Im not confident this would be the case. "Obviously" N with N and L with L wouldn't this just revert it back to the way it was?

I understand what you are suggesting and can try this.

 

[stem]

So really then, it sounds like you want to remove the relay box and just use the Sonoff instead. I thought you wanted to keep the thermostat and just use the Sonoff as remote on/off control.

You need to check out the switching wires presently in A and B to make sure that they are for 230V control, some heating systems (in the UK anyway) use 24v. Unfortunately there aren't any clues in the form of a link from L to A being present to confirm that. A and B is a voltage free switch so could be used to switching anything.

 

[KB009]

thanks I with get my multi-meter out...thanks for your input