Coleman gas furnace trouble
Coleman gas funace, model #7680C856 for mobile home worked great last year but since cold season hit, can't keep home warm (especially at night where it has been as low as 50 degrees). Thought it might be the thermostat so replaced that with new one but same thing. Thermostat clicks, burners light, blower doesn't activate for about five minutes then runs about 30-60 seconds and shuts off. Heater will kick back on about 15 min. later but same thing over and over. Tried shorting upper and lower limit switches - one shut the gas off when shorted - the other lit the burner. Please, please help if you can. Currently using one itty bitty electric space heater to heat me and kids. Thanks if you have any suggestions!!
Comment on glenb50's post
Sail switches are very rarely used in coleman furnaces. It is also unclear if this is a mobile home furnace or residential home, they have made both.