Hi everyone,
I recently installed an Aqara Floor Heating Thermostat W500 for my existing electric underfloor heating system.
The old thermostat was a T2/Raychem/Pentair NRG-DM, and the existing floor sensor seems to be either 10kΩ or 12kΩ NTC. The W500 was initially set to 100kΩ, which made the heating behave incorrectly. After changing the NTC value to 10kΩ, the heating started working much better.
However, I now have another issue:
The W500 floor sensor temperature is much lower than the actual floor surface temperature.
Example:
- W500 floor sensor: around 21°C
- IR thermometer measured on grout line: around 32°C
- Floor feels clearly warm
I found the Temperature Compensation setting in the Aqara app, but it seems to be limited to +5°C max. In my case, I would probably need closer to +8 to +10°C to make the displayed floor temperature match the actual surface temperature.
When I set compensation to +5°C, the thermostat immediately stopped heating, which proves the compensation affects the control logic. That is good, but the range is too limited for my installation.
Has anyone found a way to:
- Increase the temperature compensation range beyond +5°C?
- Use a different NTC profile, such as 12kΩ, if the app only shows 10k/50k/100k?
- Calibrate the W500 more accurately through Matter, HomeKit, Aqara settings, or firmware?
- Use another workaround to make the thermostat control more correctly with an older T2/Raychem floor sensor?
The heating cable itself works fine and draws around 480–500 W when active. The problem seems to be sensor interpretation/calibration, not the heating load.
Any ideas or experiences would be appreciated.
Thanks!
