MiniMax® NT Series - Pentair

Basic System Operation
22
TO OPERATE HEATER
1. Start pump, make sure the pump is running and is primed, to close water pressure switch and
supply power to heater. Be sure the pool and/or spa is properly filled with water.
2. Follow the Lighting/Operating instructions on the following page.
FIRING SEQUENCE
1. Pump on.
2. Heater on.
3. T-stats call for heat.
4. Pre-purge for 15 seconds (clears combustion chamber of combustible gas).
5. Hot surface igniter heat up time of 40 seconds.
6. Main valve opens for 7 seconds for flame rectification.
7. Heater runs until desired temperature is reached.
8. Gas valve closes and fan runs for 45 seconds to cool combustion chamber.
IGNITION FAILURE
1. If flame is not rectified in 7 seconds or less the heater goes into pre-purge for 15 seconds, then starts
the ignition sequence again.
2. After 3 attempts, the heater goes into hard lock
out for 1 hour and tries over again.
(Note: The fan will stay running during lockout.)
3. To get out of the 1 hour lock out you must
de-energize the heater by cutting power either
with the pool / spa rocker switch or internal
rocker switch.
HARD LOCK OUT
❖ Lock out can occur under the following condition:
INTERNAL ROCKER SWITCH
1. Heater has failed to fire on three attempts.
(Under J-Box)
❖ When a lock out occurs the heater shows a
service light, no heat light, and the exhaust fan stays running until the one hour time out has expired.
At that point the heater will attempt to fire three more times. It is important to discover why the lock
out has occurred before you attempt to reset the control board.
P/N NTSM03 Rev. B 2-11-04