Specifications

Heartland Owners Forum http://manuals.heartlandowners.org
Heating and Cooling Guide V1.pdf Page | 17 Version: 1, March 15, 2013
Troubleshooting Low or No Propane Flow
The furnace places a very high demand on propane flow. Checking the range burners for good propane
flow is a good first step if you suspect a problem with the propane supply, but because the range
doesn’t need as much propane flow as the furnace, it’s not a definitive test.
To definitively test propane flow, a manometer is required. But since most of us don’t have one, we’ll
need to try other methods.
First, go to the propane tank currently in use. Close the tank valve, wait about 10 seconds, and reopen
the valve very slowly (to avoid triggering the excess flow safety cutoff inside the tank). If that corrects
the problem, you may have just opened the valve a bit too fast.
If that doesn’t help, go to the auto-changeover regulator and manually switch it to the other propane
tank, and slowly open that valve. If that corrects the problem, you may have a problem with a failing
high-pressure pigtail from the first tank to its regulator, or you may have a failing regulator.
The pigtails and regulators are not difficult to replace. The hard part is being absolutely certain you have
the correct replacement parts. If you’re not certain, you should leave the repair to a certified
technician.
Restricted Return Air Flow
When the thermostat calls for heat, the furnace blower starts turning, blowing cold air through the
ducts. Inside the furnace assembly, a “sail switch” catches the blowing air and is designed to close if the
air is moving at 75% of normal velocity. If the return air duct is blocked, the blower may be unable to
move air at the correct velocity. To prevent a dangerous overheating condition inside the furnace, if the
sail switch doesn’t close, the furnace will not start on the propane flow. In that case, you may find that
the furnace just blows cold air.
Blocked Heat Registers
It’s quite common for the heat registers closest to the furnace to blow more hot air than you would like,
while the registers furthest away blow less hot air than you would like. Many people install adjustable
registers or cover some of the heat registers in part or in full and report some success in redirecting
furnace heat.
It’s important to note that Suburban, the furnace manufacturer, warns against blocking the registers.
Restricting airflow can result in an over-temperature condition developing inside the furnace burner
area. As a safety feature, there is a “high-limit” sensor inside the furnace. When an over-temperature
condition develops, the high-limit switch shuts off the furnace.
A symptom of a blocked register failure is that the blower may run constantly and the burner cycles on
and off. It’s possible that if this situation is allowed to continue, the high-limit switch could fail
altogether, preventing the burner from igniting.