I have a Minimax 250 running on propane that short cycles: I have to turn the thermostat to full and heater will only stay on for a short period then turn off. Sometimes I can hear it cycle several times a minute and hear gas ignite and the shut off etc. Other indications are green pressure light but red service light is on until it cycles on. I called Pentair and they think it's the thermostat. Sounds likely as maybe it thinks it's already hot when it's really only 75-80 degrees. Is there any way to troubleshoot this by jumpering the temp probe wires at the connector before I order a $150 part?