Need help with a SF 30 Suburban Furnace
My original problem was the usual story. The fan would come on and the furnace would fail to light and the fan would then shut down. I, standing outside could hear the switch and smell gas but the spa...
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https://www.airxcel.com/rv/coleman-mach/thermostats/digital-thermostats
This should be your Tstat. 6536A3351
2-Stage Heat Pump & Gas Furnace - White
It controls both Furnace and HP function. Plus AC. The color control at the Tstat will NOT be the same at the furnace to those 2 BLUE Furnace wires. AT the furnace, ONE of the 2 blue wires should be 12 volt positive. This goes back up to the wall tstat. When you select FURNACE, the second blue wire is then 12 volt positive from the wall tstat. This runs the furnace like your bench test. It makes NO difference which blue wire is used. IF one of the blue wires is 12 volt positive and when you select furnace the 2nd blue wire is NOT 12 volt pos, then you have a problem in the circuit from the tstat to the furnace and replacing a different brand/model tstat will not fix the problem. You should have 2 wall tstats, unless you have the single ZC wall tstat. If 2 just look at the wall tstat wiring of the other tstat to verify color code and how the other furnace is connected. I assume you have 2 furnaces. Doug
This should be your Tstat. 6536A3351
2-Stage Heat Pump & Gas Furnace - White
It controls both Furnace and HP function. Plus AC. The color control at the Tstat will NOT be the same at the furnace to those 2 BLUE Furnace wires. AT the furnace, ONE of the 2 blue wires should be 12 volt positive. This goes back up to the wall tstat. When you select FURNACE, the second blue wire is then 12 volt positive from the wall tstat. This runs the furnace like your bench test. It makes NO difference which blue wire is used. IF one of the blue wires is 12 volt positive and when you select furnace the 2nd blue wire is NOT 12 volt pos, then you have a problem in the circuit from the tstat to the furnace and replacing a different brand/model tstat will not fix the problem. You should have 2 wall tstats, unless you have the single ZC wall tstat. If 2 just look at the wall tstat wiring of the other tstat to verify color code and how the other furnace is connected. I assume you have 2 furnaces. Doug
