Can't tell if my heat mat is working. The first time I set it (70d f) it showed heating light on, the temperature reading went to 71.7 and then the heating light went off. The problem is, the temperature reading never seems to go down. So the mat never seems to turn on again.

I thought maybe it was the lights that were heating it but my ambient temp thermometer under the lights only says 66-68d f.

Can the lights shining on the sensor cord transfer a reading? I thought it was just the end of the sensor that could do that.

So I waited until the lights went off but the temp never seemed to come down so I unplugged the power cord for a while. When I plugged it back in, the reading was back down to 70.4 and the heating light came on again for 10-15 minutes then went off. The temp reading went up to 71.8 before it went off.

The heating turned on again an hour later but after that I went to bed so I don't know what happened all night.

I thought it should be on every 20 minutes or so.

It's only 60df in my basement so the mat feels cool, not warm at all.

Any ideas or am I just worrying?