RV Hydronic Heater Repair



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




This model may also be known as:




Note that:

The AHE-400 model is the same as AHE-450 model except that there is no dedicated stir pump (uses zone pump #2 to stir coolant) and there is no engine preheat pump.

  • Combustion chamber has been redesigned. 
  • Combustion chamber now looks like this:
  • You need to replace gasket if you remove combustion chamber, here HDE-700-205

    Common Problems


    • The PLX-100-850 pumps have not held up well.  Replace with this kit:  PLE-100-905-FRU

    Service Manual


    On Aqua-Hot website   AHE-400   Use Service Manual for AHE-400-D