Question for you HVAC guys (Now with Pictures)

[Sojourner]

Caution.......Ron & anyone else that has diesel heater in bus enclose compartment with combustible material such as wood and a possible fuel hose's leak or break (within Pro-X45's area) is asking for greater risk of SMOKE & FIRE! Not only that....always put on its own metal box cover whenever installation is finish. They can get very hot either via low or no coolant or blown soft plug on top of boiler's housing....They call it "Overheat Breaker" which melt whenever no coolant to protect it. The purpose is to avoid ultra high-pressure blowup through hot water line system.  It should shut down automatic but still you have a mess in compartment without cover.

Usually, diesel heater unit should be install in open compartment such as engine or any where outside air flow to vent unexpected fume whenever it overheat plus to access enhance cool air oxygen for hotter & complete combustion burning. Other word more oxygen per square inch.

About water pump without magnetic drive....
1) It need to be able to handle coolant's chemical properties...pump's seal.
2) To handle high coolant temperature....pump's seal         
3) It must meet its spec for flow rate at a given pressure......otherwise it can over heat.

And pump must be on & water flowing before burner is firing.

FWIW

Sojourn for Christ, Jerry