Help with my bottle heater!

I have the NOS heater and it has worked great...added the higher degree thermostats. Now, the heater will come on but then go off. A local checked the relay and the power was there. I tried putting on the spare thermostats that I had on, but now nothing works.

Any ideas?

did he just check it once or was he absolutely sure it was t the time the bottle kicked off? also just because the power is there doesn't mean it is getting grounded properly. doesn't sound like a bad relay, more like a loose wire.