RV Hydronic Heater Repair



This model of Aqua-Hot uses the special Camco -100 Boiler coolant.




This model may also be known as:



Changes From Previous Model


This model is a major redesign of the AHE-450-DE1 model


Changes made on this model:


  • Solid fuel lines (instead of rubber fuel lines that are in all previous models)
  • NO RADIATOR cap - Zero pressure system
  • Recommended exhaust pipe is 2" ID (up from 1 5/8")
  • Has case interlock switch that will not allow burner to run until switch is depressed
  • High limit thermostats are now set to trip at 215° (up from 220°)
  • Some heaters in this series have tank liquid SENSOR in place of the mechanical float switch.  This tank level sensor is no longer available, see replacement below.
  • Coolant lines check valves are now mounted horizontally
  • Aqua-Hot is installed in a 'tray' that is installed first.  Aqua-Hot is then mounted in coach using this tray.

Part Notes


  • Control Thermostat -   ELE-014-010
  • Electric high limit thermostat - ELE-HLT-322   -or- with terminals crimped on  ELE-ASY-200-HYD
  • Diesel high limit thermostat -  ELE-HLT-322 
  • Control Board -  ELE-PC4-010  This control board will directly replace the 008 and 009 models.  You may have to crimp different (larger) terminals on 12-VDC supply wires.
  • Tank level sensor (float switch) - ELX-800-002 - Brass float
  • Zone, stir and engine preheat pumps (are no longer available).  Pump upgrade kit, here: PLE-100-905-FRU
  • Radiator cap - PLX-102-229
  • Uses 'screw in’ Low Temperature Cutoff Thermostat - ELE-000-606
  • Reconditioned Webasto burner - WPE-905-834-R



Routine service parts and kits - Routine Service Parts      Scroll down page for filter and nozzle packages.



Common Problems


  • Stir pump failure -  Upgrade kit, here:  PLE-100-905-FRU
  • Rubber boot on air intake for Webasto.  Recommend removing rubber boot because it can restrict air intake into Webasto burner.  Kit to cover air intake with screen is here:  Air Intake Screen

Service Manual


On Aqua-Hot website   AHE-450-DE2  Scroll down page in "Discontinued Aqua-Hot Products" section