AQUA-HOT SERVICE AND REPAIRS

Aqua-Hot systems are similar to a residential "boiler" system. Whenever an interior room thermostat "calls for heat," the heater's hot water solution is then circulated through interior heat exchangers (similar to radiators) located throughout the motorhome. Multiple circulation pumps allow for independent interior heating zones, while our heat exchangers are designed to gently disperse heat quietly and evenly throughout the motorhome.
Our technicians are factory certified to perform service and repair of all Hydronic systems. 12 months labor warranty.

When the diesel portion of your Aqua-Hot starts it goes into a starting sequence:

1. The blower motor starts, which starts the fuel pump.
2. The motor runs for about 10 – 20 seconds to allow fuel pressure to build up and stabilize.
3. The fuel solenoid opens (spraying fuel into the burning chamber), the ignition coil starts creating a spark across the electrodes (igniting the fuel that has been sprayed into the burning chamber).
4. There is a very slight delay. The photocell (that is adjacent to the burning chamber) looks for light from the burning diesel fuel.
5. If the photocell sees light, everything is good and the burner will continue to run.
6. If the photocell DOES NOT see light, the fuel solenoid closes and the `diesel' light next to the switch in your coach goes out. The blower continues to run (purge cycle) for about 2-3 minutes to purge unburned diesel (and heat if the unit has been running).
7. Blower motor shuts down.

As you can see, this is a complicated sequence. If ANY component fails to operate properly, the diesel burner will not operate.  This repair and troubleshooting can be difficult.  You many need to seek out authorized repair technician.  We have some testing equipment that allows us to check out each component involved in the start up sequence separately.

It could be any of the following items that have failed.  Fuel pump, solenoid valve, clogged nozzle, ignition coil (+wires + electrodes), or photocell.  On the older (non electronic control board) Aqua-Hot, the high limit thermostat. 

If you had to reset one of the thermostats, it probably was the high limit thermostat. You need to find out what caused your unit to overheat.