I have central heat. the whole unit is about 10yrs old. The unit will kick on then after about five minutes it will kick itself off. After about another five minutes or so, it will kick back on again. It'll do this several times before actually staying on for a full cycle. We replaced the thermostat about two months ago. We had a digital programmable one before then we switched it to a simple adjustable lever one. Could our problem be the thermostat or the unit itself. Our house is around 80 yrs old and off the ground and it is hard to regulate the temperature in an old house like this, but we never had a problem with the central ac/heater unit like this before. I hope you will be able to help us. Thanks

Heating & Cooling - Mr. Heater - Model MH12TS - Single Tank-top Propane Heater