Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Recommendations for smart thermostat


I live in SW France.

I run a Buderus G215 fuel boiler operating via a Buderus Logimatic R2109 controller. The heating system is connected to a Flash Thermoflash thermostat which has a three wire connection. Which I believe is 230v. The system incorporates a hot water tank which is controlled by the logimatic R2109.

The current thermostat is old fashioned and badly placed within the house. The house is large, 450 m2 on three floors but is not zoned. Most radiators are controlled by thermostatic valves.

I want to convert the system to run with a smart thermostat that I can operate remotely and move around the house to an appropriate site to better balance the overall heating. At the moment the upstairs radiators cut off before the rooms are up to temperature because the thermostat is on the ground floor. I like systems where I replace the thermostat with a base unit and have the thermostat operating wirelessly.

I have tried contacting the various manufacturers, Nest and Honeywell to see if there is a compatible system. I was thinking the Honeywell Lyric T6 looked like it may fit the bill but getting an answer from them that I can understand is like wading through treacle.

Can anyone give me a definitive answer one way or the other.

Many thanks


    HVACNUT Member Posts: 5,861
    edited September 2017
    I'm not 100% sure, but the Honeywell RedLINK wireless thermostat should work.
    In the U.S., the 2109 has 24v switching for the thermostat. Your thermostat being 230v, I'm assuming there is a switching relay with a 230v coil at the boiler to open and close the low voltage contacts to the 2109 thermostat terminals.
    I don't know if Buderus manufacturers a 230v Logamatic for European applications.
    If they did, a switching relay with a 24v coil would be needed.
    If switching is 24v in the 2109, then wire the interface module to the 2109, and you can go room to room with the thermostat.

    For WiFi, you'll also need the RedLINK Internet gateway.