Coolant System Maintenance
By: Clarke Service

To maintain optimal performance, the Clarke Heater System needs to be regularly maintained.

Per recommendations from the engine manufacturers, it has become necessary that engine coolants be changed every 12 months using Clarke Coolant (part # C054129). The only acceptable substitute is COOL-GARD IITM.

The recommended maintenance instructions pertaining to the coolant system are as follows; Warranty is contingent on utilizing the indicated coolant:

• Have an authorized person take the engine “Out of Service”.
• Disconnect electrical power to the heater system.
• Drain the coolant from the drain port / lowest section of the system.
• CAUTION: Coolant may be Hot.
• Replace all hoses according to the schedule defined in Clarke’s operation and maintenance instruction manuals on the Clarke website.
• If during this process hoses are found to be brittle, inflexible or showing signs of swelling, replace them immediately instead of waiting for the standard 2-year replacement.
• If coolant has been changed more than once and particulate is found, replace the heater.
• Flush the system with clean water until clean / clear liquid comes through the outlet.
• Drain remaining water.
• Reconnect all hoses and close drain points.
• Refill system slowly with coolant until the system is full.
• Do not mix coolants.
• Reconnect power to system / heater.
• Run the engine in weekly test mode to verify the system is leak free. After engine has been stopped, verify coolant in the expansion tank has returned to the proper level. Refill if necessary.
• CAUTION: Wait until engine has cooled before removing the coolant system pressure cap. Pressure may exist.
• If there is any concern over the coolant in-between 12 months cycles contact Clarke for a coolant test kit, Clarke Part# C12E126.