We have a Lennox Pulse Propane furnace that is currently not working. The propane tank was locked for three months this summer, but has been unlocked for a month or so and is 85% full. I turned the valve on the tank back on and followed the procedure on the furnace (it does not have a pilot light) which consisted of turning the electric switch to off and taking a door off the furnace and turning a knob to off and back to on and then switching the electric back on. When I turned the thermostat up it would try to start three times and then not again, and it only blows cold air. When it tries to start it will only try for a couple of seconds. We are thinking there is air in the gas line, so I have tried to bleed it by turning the electric switch off and then back on and turning the thermostat up. I have done this maybe 15 times over the past few weeks and always get the same result. Is there anything else I can try on my end before calling a professional out?
Thanks for your time!