What if Mysa for Baseboards Gen3 does not fit my wall box?

Audience: Mysa Customers.

Mysa for Baseboards Gen3 has a rear housing that sits partly inside the wall box. In some older or shallow wall boxes, especially boxes that are shaped more like a light-switch box, the thermostat may not sit flush or may not physically fit.

Do not force the thermostat into place

• Do not force the thermostat against the wall box.

• Do not file, cut, or modify a metal electrical box yourself.

• Do not continue the installation if the wiring or box fit is uncertain.

Line-voltage thermostat installations should be handled safely. If the thermostat does not fit, stop the installation and contact a qualified electrician or Mysa Support before making changes to the box or wall.

What to check

1. Confirm you are installing Mysa for Baseboards Gen3 in a compatible line-voltage electric heating setup.

2. Compare the wall box depth and opening with the thermostat body. Gen3 product specifications list the thermostat dimensions as 145 × 99 × 48 mm (5.7 × 3.9 × 1.9 in).

3. If the box is too shallow, rounded, narrow, or an older style that blocks the rear housing, ask an electrician whether the box can be safely replaced or adapted.

If the box cannot be changed

If an electrician confirms the wall box cannot reasonably be changed, the best next step may be to return the thermostat and choose another compatible option. Return and rebate eligibility can vary by product, purchase channel, and promotion, so contact Mysa Support before ordering a different model if you used a utility offer or rebate.

Need help?

Send Mysa Support clear photos of the wall box with the power off, the old thermostat model if available, and the heater type. Do not include personal information in the photos beyond what is needed to understand the installation.