Section 7, Plumbing the System
International Thermal Research 7-7
Prior to operating the engine pre-heat pump, the engine coolant loop
must be connected to the engine heat exchanger, and the coolant
lines purged of air. Failure to purge the engine coolant loop prior to
operating the circulation pump, will damage the pump.
7.6 Procedure for Filling/Purging the Oasis
SCH33 Heating System
Do not operate the Oasis SCH33 until the entire circulation
system has been filled with the proper heat transfer fluid
solution and all trapped air has been bled from the system. An
inadequate mixture may cause system circulation problems and
potential system damage and/or personal injury.
Use only a non-toxic, propylene glycol-based coolant with
additives recognized as safe “GRAS” by the FDA. Refer to the
anti-freeze/heat transfer fluid manufacturers recommendations
and instructions for your application.
Remove the front cover of the Oasis SCH33, also remove the
cover of the control board to provide access to the circulation
pump jumper on the circuit board See diagram below. Using a
self-priming pump, fill the system through the filler port (1/2"
hose barb connection) located at the bottom of the tank with
the proper mixture of propylene glycol-based antifreeze/heat
transfer fluid. Some manufactures refer to heat transfer fluid as
boiler anti-freeze; the solution is often pre-mixed and should
not be diluted. See the manufactures recommendations for
dilution requirements if the fluid is not pre-mixed.
When the fluid starts to run into the overflow bottle, turn off
filling pump and place the pump circulation jumper onto both
pins on the control circuit board. The Oasis SCH33 internal
pump will run and circulate fluid through the entire system. The
fluid level in the overflow bottle will drop as the air in the
system is displaced with fluid. Turn on the filling pump and
refill the overflow bottle to the "Minimum when cool" level.
When this level is reached, turn OFF the filling pump, and keep
the jumper in place until the system is purged of air and the
coolant level in the overflow bottle does not change.
To Next Page