RV Hydronic Heater Repair

Webasto Shipping Directions


Shipping and Webasto Removal Directions


  • Remove Webasto and inspect combustion chamber. Combustion chamber should be round and not be cracked on the seam more than 1". If you have any question, ship that too.
  • Include silver box, so I can check that too for proper operation. Package separately in box. Do not leave attached to Webasto. If you leave it attached to the plastic cover it can break the plastic if handled roughly in shipping.
  • Install something over the nozzle and electrodes to protect them during shipping.
  • Package Webasto in shipping box with ignition coil facing down and fuel lines up. It seems to travel the best this way.
  • Do not ship without wiring harness. That way I can completely test, assemble unit and make it ready for reinstall. Directions below on how to remove fuel lines and thermostat wires (scroll down.... page is long)


To remove thermostat wires

431 Series


Remove sheet metal cover and pull connectors off of left side thermostats.


Caution: Thermostats on right may have 110-volts on them. Turn off circuit breaker to Aqua-Hot electric



431 series looks like this

Hydro-Hot Series


Unplug plastic connectors



Unplug plastic connector and pry


Remove fuel lines

Some Aqua-Hot units have unions. Some just use barbed connections.




Tape or fasten cover to protect nozzle and photo disc during shipping.  I use plastic container like this:


Send Webasto and silver box. Leave wiring harness attached to Webasto. Remove wires from thermostat as shown below.


Remove, clean and inspect combustion chamber.  If you have any questions, send that too.


Read directions on how to remove Webasto and contact me if you have questions.