My Ducane gas heater ignites but then shuts off. A proffessional can't find the problem. He has cleaned it, changed the filterjumped the theristat, put on a new pressure switch, put on a new flame sensor and examined everything else he could think of.
Please help! I'm running out of money and patience.

Thank you
belll1962

Is he checking these parts or just replacing them? Is he using a meter? Does your furnace have any trouble shooting codes (LED) on the circuit board? It sounds as if he is just changing parts hoping to get the right one. How long does the furnace run? Is he checking the low voltage circuit to see what is droping out the power? Sounds like possibley a problem grounding issue with the flame sensor.

Replace the wire on the flame sensor unless the one he replaced came with a new wire. This has been mentioned on this board by others as a cure for this problem.