RV Hydronic Heater Repair
This model may also be known as:
920/431, 920431/12, 920/432, 431
Most of these heaters were 12-volt,
however there were a few 24-volt heaters built.
This model of Aqua-Hot uses 'standard' ethylene glycol coolant (Prestone or equal). Keep it simple and use the same coolant that is in your engine and generator.
Thermostats are ELX-560-213, which are no longer available.
3 zones + engine circulation pump PLX-809-200 Used pump, here: PLX-809-200-U
1650 watt electric element ELX-2E7-540 Note: that electric element rarely fails!
Most failures in electric system is electric high limit thermostat.
Replace filter and nozzle when exhaust gets smoky / smelly. Aqua-Hot recommends yearly routine service.
Recommended Service Parts to Keep On Hand
Filter: VERIFY FILTER: Normally one of filters below.
Webasto - WPX-603-359
Racor R12T FLE-R12-TRA
Optional Service Parts to Keep On Hand
AHE-100-02S - On Aqua-Hot website