Heartland Owners Forum http://manuals.heartlandowners.org Heating & Cooling Guide This guide is intended to assist Heartland Owners in understanding how to use and do routine maintenance and troubleshooting on their heating and cooling systems. Important Notices Who created this document? This document has been created by Heartland Owners independently of the Heartland RV Company, and is posted to the Heartland Owners Forum as a service to the owner community.
Heartland Owners Forum http://manuals.heartlandowners.org Heating & Cooling Guide Table of Contents Thermostats .................................................................................................................................................. 4 Dometic Single Zone LCD Thermostat ...................................................................................................... 4 Checking and Changing the Set Point Temperature ............................................................
Heartland Owners Forum http://manuals.heartlandowners.org Fan Operation ......................................................................................................................................... 12 Coil Freeze-Up ......................................................................................................................................... 12 Routine Maintenance .........................................................................................................................
Heartland Owners Forum http://manuals.heartlandowners.org Heating & Cooling Guide This guide is based on the Dometic Thermostats and Air Conditioners, and Suburban Furnaces commonly found in most Heartland RVs. Thermostats The living room thermostat is the primary control for either your living area air conditioner (or heat pump), and your furnace. The bedroom thermostat controls only the bedroom A/C or heat pump.
Heartland Owners Forum http://manuals.heartlandowners.org Heat Pump or Heat Strip Mode: If you have this option, cycling to this mode will put the air conditioner into heat pump mode, or if you have a heat strip, will activate the heat strip. These act as an alternative to running the furnace when heat is needed.
Heartland Owners Forum http://manuals.heartlandowners.org degrees higher than the Set Point, the fan will run on HIGH. If between 8 and 4 degrees above the Set Point, the fan will run on MEDIUM. When the difference is less than 4 degrees, the fan will run on LOW. The UP and DOWN buttons control the temperature set point. The ZONE button should not be used. Leave the thermostat set to zone 1. The current temperature set point is displayed on the LCD. The LCD display automatically dims.
Heartland Owners Forum http://manuals.heartlandowners.org Analog Thermostat Wiring There is an informal or “loose” wiring standard for thermostats, but exact terminal functions can vary from manufacturer to manufacturer. Yours may be different, or use different color wiring, but the basic functions will be similar. You can rely more on the terminal designations than you can the wiring colors for wiring or troubleshooting. Here is a typical chart for the thermostat and equipment terminals in your RV.
Heartland Owners Forum http://manuals.heartlandowners.org Generally, with the fan on HIGH speed your discharge temperature at the main air dump should be about 20 degrees Fahrenheit lower than the air entering at the return air grille. That will hold true up to about 90-95 degrees outside, when the cooling efficiency begins to go down.
Heartland Owners Forum http://manuals.heartlandowners.org the cold air streams. In most cases, the bedroom unit will quickly cool the bedroom down and the air stream can then be directed toward the hallway to help cool the living area. Toy Haulers with Three Air Conditioners Some of the toy hauler trailers have an option to install a 3rd air conditioner in the garage. Operation is similar to the living room and bedroom air conditioners.
Heartland Owners Forum http://manuals.heartlandowners.org Dealing with Very High Outside Temperatures Stay Ahead of the Heat The most important thing you can do is to keep ahead of the outside temperature. Take advantage of cooler morning temperatures and cool the interior to the lowest temperature you can tolerate. Then as the heat load increases in the afternoon, even if the air conditioner can’t keep up, the trailer will still be reasonably comfortable.
Heartland Owners Forum http://manuals.heartlandowners.org Electrical Loads A/C Units Air conditioners are rated for their capacity in British Thermal Units (BTUs). The higher the BTU rating, the more capacity it has to move heat, and the more electricity it requires. All of our RV air conditioners run on 120 volts AC. If you have two air conditioners on your coach, your coach will also have what is referred to as 50-Amp RV electrical service. The 50-Amp service consists of two 120 volt, 50-Amp circuits.
Heartland Owners Forum http://manuals.heartlandowners.org Short-Cycling When the air conditioner is shut off by any means (loss of power, thermostat cycled to OFF, or the thermostat reaching the set point and turning it off) it should not be restarted for several minutes. This is to allow the refrigerant gas to equalize and the compressor motor to cool down. (That is the hissing sound you hear when the A/C shuts off). If the motor tries to restart too soon, it can cause an over temperature condition.
Heartland Owners Forum http://manuals.heartlandowners.org amount of icing. You might also get some condensation dripping out of the return air grille. Keep an eye out for this, especially with the bedroom unit, as no one likes a wet bed. Routine Maintenance Cleaning the Return Air Intake Filter(s) The air conditioners have a washable filter media located directly behind the return air intake grille(s). You should be able to see the filter(s) with the grille in place.
Heartland Owners Forum • http://manuals.heartlandowners.org Clean the outside coils. Modifications to Improve Airflow Through A/C Ducts The living room air conditioner sends much of the cold air through the main air dump, and the rest through the duct system. Depending on the layout of the trailer, this can result in uneven distribution of cold air. If the main air dump is further forward, the seating area at the very rear of the coach may not get as much cold air as desired through the ceiling vents.
Heartland Owners Forum http://manuals.heartlandowners.org Furnace Operation Normal Sequence and Theory of Operation When the thermostat is set to heat mode and the sensed temperature falls below the thermostat set point, the furnace will start. First, the fan comes on for about 20 seconds. This is to purge the combustion chamber of any potential gas. There is an air flow switch (sail switch) that must close before the furnace will even attempt to light.
Heartland Owners Forum http://manuals.heartlandowners.org 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.
Heartland Owners Forum http://manuals.heartlandowners.org 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.
Heartland Owners Forum http://manuals.heartlandowners.org Propane characteristics in cold weather As outside temperatures fall below freezing, propane pressure from your tanks may fall below what’s necessary for reliable furnace operation. Propane gas pressure at 0 degrees (F) is about ½ the pressure from the same tank at 50 degrees (F).
