P/N 472128 Rev. C 1-22-04
18
Possible Cause Remedy
Heater will not come on
Pump not running Place pump in operation
Pump air locked Check for leaks
Filter dirty Clean filter
Pump strainer clogged Clean strainer
Defective wiring or connection Repair or replace wires
Defective pressure switch Replace switch
Defective gas controls Call serviceperson
On-Off switch in "OFF" position Turn switch to "ON"
Heater Short Cycling (Rapid On and Off Operation)
Insufficient water flow Clean filter and pump strainer
Defective wiring Repair or replace wiring
Defective flow valve or out of adjustment Call serviceperson
Defective hi-limit and/or thermostat Call serviceperson
Heater Makes Knocking Noises,
Make sure all valves on system are open
Heater operating after pump has shut off Shut off gas supply and call serviceperson
Heater exchanger scaled Shut off gas supply and call serviceperson
Troubleshooting - General
CAUTION
Please consult the latest edition of the “MiniMax Service Manual” for complete service and repair
instructions. Repairs should only be attempted by properly trained service personnel.