03 Heating and Air Conditioning

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Aqua-Hot Heating System

The Allegro Bus features an Aqua-Hot heating system (Figure 3-1) that provides a continuous, on-demand supply of domestic hot water, as well as interior zone.

Both heating features are accompanied by a unique VDC powered diesel-fired burner, and a VAC-powered electric heating element (120 VAC). These two heating sources maintain the temperature of the Aqua-Hot’s solution of water and anti-freeze.

If interior heat and hot water are both needed at the same time, the hot water will take precedence over the interior heat, causing the interior heat to shut down and turn off until the water flow is turned off from the water sources.

Te surge tank (Figure 3-2), which is located in the basement, should be routinely inspected to make sure the anti-freeze fll line stays in the acceptable zone. If the anti-freeze becomes low, you must add the recommended anti-freeze stated in the Aqua-Hot’s owner’s manual.

If anti-freeze is totally depleted from the surge tank, a switch will be released inside the main Aqua-Hot tank, disabling the system from operating. Anti-freeze will then have to be added to the tank to reactivate the switch and allow the system to operate. If batteries become discharged and the Aqua-Hot system is activated, the system will automatically shut down before the batteries are totally discharged. Once power is restored to the batteries, the system must be reset by depressing the reset button on the black panel of the surge tank. For detailed operations on using the heating system, refer to the owner’s manual in your Tiffin Owner’s Information Package.

Air Conditioning System

The factory-installed air-conditioning system is designed for 120 VAC power supplied either from the external power cord or from the generator. For the best cooling scenarios, park the motorhome in a shaded location whenever possible and close drapes on the windows exposed to direct sunlight.

The air-conditioned, cooled air is emitted through the vents (Figure 3-2 to Figure 3-4), which are located in the roof throughout the entire coach along the passenger side. The return air vents run parallel, front to back, on the ceiling along the driver’s side of the coach. The return vents are similar to the air conditioning vents, but they contain foam filters that keep dust from flowing back through the air conditioning system. The return filters can be easily removed and cleaned with warm water and a mild cleaning solution. To remove the filter, pull the vent down and lift the filter from inside the opening.

Air Conditioning Controls

The following is a brief overview of how best to use the thermostat. For more detailed instructions, please consult the thermostat literature in the Owner’s Information Package.

Use the “Thermostat” switch to select the desired function (e.g., COOL, OFF, GAS HEAT, or ELEC HEAT).

Note: In the “COOL” mode there will be a delay of several minutes before the refrigerant in the air-conditioning system begins to cool the motorhome, as the compressor is on a time-delay circuit and it must also cool the ductwork to the vents first.

Select the Fan Mode operation (AUTO or ON) and the Fan Speed operation (LO or HI) to select fan speed desired.
Press the Up and/or the Down buttons to set the desired temperature for the motorhome.

NOTE: When the fan mode is in AUTO, the fan will cut on and of when the temperature reaches the desired setting. When the fan mode is on FAN, it will continue to run even though the compressor cycles on and of when it reaches the desired temperature. If the motorhome temporarily loses its 110 power, the air conditioning system will resume operation at its last programmed setting once power is restored. If 12v power is lost to the thermostat, it will automatically re-set to 72 degrees once power is restored.

NOTE: There is a thermostat control for each air conditioning unit, one located in the bedroom and one in the living area.

Heat Pump Controls

To activate the optional heat pump, set the thermostat to the ELEC HEAT mode and select the desired temperature.

NOTE: If the setting on the thermostat and the room temperature are more than five degrees apart, the Aqua-Hot heating system will automatically turn ON with the heat pump. Once the room temperature reaches the desired level specified on the thermostat setting, the furnace will cut off and the heat pump will maintain the heating of the coach.

NOTE: The heat pump is controlled by each individual thermostat.

If the external temperature falls to 45 degrees Fahrenheit, the heat pump will become inoperative and the gas furnace will begin to operate automatically.

On the A/C controls page, press HEAT PUMP to activate the heat strip on the rooftop A/C unit.

NOTE: You will see the snowflake icon change to a heating symbol beneath the arrows. After a slight delay, the heat pump icon will begin to flash. When the heat strip on the rooftop A/C engages, the heating symbol beneath the arrows will change to red, and the fan icon will indicate the fan speed.

NOTE: The heat pump refers to the electric strip on each exterior rooftop A/C. The FURN button refers to the Aqua-Hot.