Why does my thermostat say test monthly?

“Test Monthly” on a Warmup thermostat unit indicates that the unit has built in GFCI (ground-fault circuit interrupter) protection. To ensure the GFCI is properly functioning, the test monthly tab on the bottom of the unit can be pressed while the floor is heating up. If a “Ground Fault Error” message appears, the thermostat is in working condition.

If you do not get a “Ground Fault Error” message when you press the test monthly button on your 4iE first confirm that the unit is sending electricity to the floor. The thermostat must be active to perform this test. An active thermostat has a target temperature higher than the current temperature. On the large temperature format setting, an active unit has a triangle as a heating indicator between *F/C and Floor/Air on the right of the large number in the center.