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 mechanically the same as previous model - HHE-200-09x with the following changes


  • White (powder coated) case instead of the galvanized sheet metal case in previous models
  • Pumps are mounted to case with nylatch connectors (Nylatch Kit) instead of being pop riveted to case, which makes pump replacement much easier
  • Drain valve is now on rubber hose with valve on end.


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
  • Hot water connection on back of heater should be periodically replaced.  The gaskets in the PEX fittings get hard and will sometimes leak. Replacement "Kit" is here:  Hot Water Line Kit

Service Manual


On Aqua-Hot website   AHE-450-DE1  Scroll down page in "Discontinued Aqua-Hot Products" section