Problem with Suburban SF furnace
Hello everyone, I was hoping that maybe there would be an expert on this forum that could help me. Currently I am living in my 1975 GMC Motorhome on a six month contract on Charleston SC. During las...
Forum Discussion
You have indicated why the high temp limit switch is cycling........
"The person that replace the 1975 unit with this unit really did not know what he was doing. the Vent are to small."
Ducting too small for the size of furnace will cause excessive heating.....as you have found out (VERY HOT..then HOT air discharge)
Excessive heat can cause the combustion chamber to crack.......a cracked combustion chamber is a leak...a leak that can allow CO into the inside of RV. CO can KILL.
Need to increase duct work......add more ducts
OR change main gas orifice to a smaller size
Make sure you do NOT have anything blocking air return or in close contact with furnace box.
Make sure your CO Detector is functioning properly
Address this problem ASAP!
"The person that replace the 1975 unit with this unit really did not know what he was doing. the Vent are to small."
Ducting too small for the size of furnace will cause excessive heating.....as you have found out (VERY HOT..then HOT air discharge)
Excessive heat can cause the combustion chamber to crack.......a cracked combustion chamber is a leak...a leak that can allow CO into the inside of RV. CO can KILL.
Need to increase duct work......add more ducts
OR change main gas orifice to a smaller size
Make sure you do NOT have anything blocking air return or in close contact with furnace box.
Make sure your CO Detector is functioning properly
Address this problem ASAP!
