Specifications

Heartland Owners Forum http://manuals.heartlandowners.org
Heating and Cooling Guide V1.pdf Page | 16 Version: 1, March 15, 2013
Routine Maintenance
There is no filter for the furnace air return. The only regular maintenance is to regularly inspect the
furnace air intake and exhaust vents on the outside of the coach for obstructions. Look for evidence of
insects, spiders, mud daubers, etc. Also check regularly for soot buildup around the exhaust vent.
Common Problems
The most common problems affecting the furnace are:
• Low voltage from the battery/power converter
• Low or no propane flow
• Restricted return air flow
• Blocked heat registers
Low Voltage
The furnace blower, circuit board, and gas valve all depend on 12V DC power. If you are connected to
shore power, this is generally supplied by both the power converter and the battery. If you are boon
docking, the voltage comes from the battery.
The furnace blower consumes quite a bit of current and can run a battery down in one night when boon
docking. You may need more than one battery for cold weather boon docking. Using a generator to
recharge the batteries during the day is a common practice.
There is a 12V circuit breaker where the power converter and battery come together (usually located in
a group of automotive type circuit breakers near the battery). If that circuit breaker trips, the power
converter will no longer charge the battery. When on shore power, you may not notice that the battery
is not charging, because the power converter supplies the required 12V power to the interior lights and
to the furnace. The problems generally start up when you disconnect shore power. There is more on
this topic, along with diagrams and other troubleshooting assistance in our
12V Block Diagram &
Diagnostics guide, located in the manuals section of the Heartland Owners Forum.
Low or No Propane Flow
When the thermostat calls for heat, the furnace blower starts turning, blowing cold air through the
ducts. A short while later, gas flow is started and ignition is attempted. Inside the furnace, a flame
sensor determines if ignition succeeded. If the flame sensor doesn’t indicate that the burner is on, the
propane flow shuts off.
If propane flow is marginal, ignition may succeed, but the burner may not be hot enough for the flame
sensor to be triggered, and the propane valve will be shut off. In some cases, the flame sensor may
indicate success, and the furnace may produce lukewarm air. As the propane supply fluctuates, the
burner temperature can drop. The flame sensor will act as though the burner has gone out. The
propane valve will shut off.
A common symptom of low propane flow is to wake up to a cold interior, with cold or lukewarm air
coming out of the heat registers.