Generally, the heater panels are 99% robust and what tends to be the issue is a connection. Usually, one of the Molex connectors has not been correctly clipped together during installation or has come loose at some point.
To resolve, try checking all connectors in the roof and under the bench. The connectors on the roof are located in the small hatches left and right and also in the back. They are all the thick black and white wires. Please make sure that they are all clipped together correctly.
Below is a video to walk you through this process for under the bench, however the same method of checking can be applied for the roof;
If unsuccessful with the above advice please feel free to get in touch with our Customer Care team.