On a recent trip with low outside temperatures, I had a hard time keeping the driver and passenger area warm with the dash heating. With thermostat set to highest setting, while driving approximately 65mph, the air would be cool to barely warm. When I would slow down or stop and idle, like going through small towns or stopping at rest stops, the temperature would warm up and heat the area just fine, then back on the highway and things would cool off fast. According to the vmspc, my coolant temp was 178 degrees. Have others experienced this problem? Anyone have a possible solution? Do I need a hotter coolant system thermostat or maybe thermostat control for heater system? Engine thermostat was replaced past spring when I had the radiator flushed. Open to any suggestions.
Seems like the recirculate door is not working letting in fresh air when moving.
Do you have a switch for the AUX Pump? I have to run mine to get heat when it's chilly to get enough coolant to flow up front.
I've got a similar issue and I think it's a door issue, like Craneman said. For now, I just turn on zone 1 heating, from the Aqua Hot, which is also kept hot by the engine.
I have had other brand's that had a circulation pump up front to pull the heated coolant to the front, otherwise I have never known coaches to put out enough heat. There is a lot of front glass and it's hard keeping the heat in. Usually have to use supplemental heat. I have used electric heaters up front plugged in running off my inverter
This effect at speed is a common issue for many class motor homes. The problem is a combination of the air inside getting exchanged at speed and the heating system either getting overwhelmed by the excess air pressure underneath the front cowl or the fan getting stalled.
Setting the AC control to "Max AC" should partly close off the outside air damper which will help some.
If you have hydronic heating with the ability to use engine heat, which may also include engine preheat, set the inside thermostats to the temp you want and then the zones to furnace, or gas, or whatever is needed to run the cozies. You can leave the burner off.
Using electric heaters ultimately supplied by the engine alternator is not the best choice. A 1.500-watt heater can draw up to 150 amps at 12 volts after inverter losses.
Thanks for the great replies. I will start by checking out the operation of all the doors that deflect air. All of the ductwork components are 24 years old and probably due for a little maintenance. Thanks again for your responses and I will update when I have results.