Your combat vehicle’s A20 personnel heater, NSN 2540-01-396-2826, will keep you warm when the temps drop. But neglect the proper start-up procedures and your heater will give you the big chill!
Sometimes operators hold the RUN-OFF-START switch on START too long. After 10 seconds in the START position, the heater automatically goes into a 4-minute purge mode. The heater’s fuel supply cuts off and all remaining fuel inside the heater burns off.
Because the heater won’t start, most operators assume it’s defective and turn it in for repair. But the heater’s not the problem! It’s the improper start-up procedure that causes all the trouble.
To start the A20 heater correctly, hold the RUN-OFF-START switch on START for four
(4) seconds, then flip it to RUN. The heater will go through a quick self-diagnosis and then should start.
If the heater still won’t start, check out the troubleshooting procedures in TM 9-2540-207-14&P (Jan 07).
And if your vehicle is an M1A2 SEP or M2/M3 Bradley, refer to your TMs for vehicle-unique starting instructions.