Internal: In-Floor floor temperature overshoots the setpoint in Floor Mode

Audience: Internal (CX Agents Only)

Applies to: Mysa for In-Floor Heating in Floor Mode.

Customer problem

A customer may report that their floor temperature rises several degrees above the Floor Mode setpoint, or that the thermostat's ambient display does not match a separate room thermometer immediately after the faceplate has been removed and reattached.

Reusable explanation

Mysa for In-Floor Heating does not use proportional control in Floor Mode. It uses on/off control with a fixed deadband. When it calls for heat, the floor heating system runs at full power until the thermostat stops the call.

Radiant floors have thermal mass. Tile, concrete, mortar, and the heating cable can continue releasing stored heat after the relay opens, so the floor sensor may keep rising briefly instead of dropping immediately. This can be more noticeable when the room is already warm, because the floor cannot shed residual heat as quickly.

If the ambient display reads lower than another thermometer right after the faceplate was removed, let the device stabilize after it is reattached. The thermostat applies internal temperature compensation for its own electronics. A cooled faceplate can temporarily make the displayed ambient reading look low until the device warms back to normal operating conditions.

Suggested agent response

• Confirm the thermostat is in Floor Mode and that the floor sensor is installed and selected correctly.
• Explain that some overshoot can happen because radiant floors coast after heat turns off.
• Ask whether the pattern persists when the room/floor are not already warm and whether the floor continues rising far beyond the setpoint.
• For sensitive flooring, confirm Smart Limit Protection is configured to the flooring manufacturer's maximum temperature recommendation.
• If the ambient reading remains consistently inaccurate after the faceplate has stabilized, or if the floor temperature overshoot is severe or unsafe, collect device logs/photos and escalate for technical review.

Do not say

• Do not promise a future temperature-offset feature or timeline.
• Do not tell customers to ignore large or unsafe floor-temperature swings.