Heater Craft 900H Series Hydronic Heaters - Manual (Page 7)

Page 6
Testing The Installation
Winterizing
Warning: Carbon Monoxide (CO) is emitted from the engines' exhaust. Do not run the engine without
proper ventilation. Do Not run the engine in a confined space or where back drafting may occur.
1. Test the fan motor on all settings.
Note – If the airflow does not correspond to the switch setting, the wires are not on the proper terminal.
Refer to the wiring diagram and recheck the switch wiring.
2. Check all hot-air outlets to make sure there are no air restrictions.
3. Prepare to run the engine.
Warning – Keep hands, hair, loose clothing and tools away from all moving parts.
Caution – Make sure the water source is properly connected to the engine.
Raw-Water Cooled Engine
1. Run the engine and check for leaks at the hose barbs, hose connections, heater hose, and heater core.
Closed Cooled Engine
1. Refill engine-cooling system to the required level. Operate engine until normal operating temperature is
reached.
2. Shut off the engine and check the heater core, hose connections, and all hoses for coolant leaks.
3. After engine has cooled, recheck the coolant level.
Note – On an engine application it is necessary to increase the engine RPM to create effective hot water
flow. Shop testing will not always provide adequate water temperature or flow to test the maximum air
temperature output. Certain engine applications may require a water test to achieve actual heater output.
Raw-Water Open Cooled Engine
The heater unit and hoses should be drained of water to prevent freeze damage. This can be done by
removing the hoses at the engine and blowing the water out of the heater unit and hoses. An RV anti-freeze
or water/anti-freeze solution can be added for extra protection and to prevent rust or corrosion.
Caution – Do not exceed 35 psi when blowing out the heater core.
Freshwater closed cooling
It is not necessary to winterize as long as you are using a sufficient water/anti-freeze solution as needed for
the climate conditions in your area.
Questions regarding winterization please call Technical support (208) 687-4400 or log on
www.heatercraft.com and fill out a technical support request form and a qualified Heater Craft
represenative will be in contact within 24 hours.