TM 9-2540-205-24&P
TROUBLESHOOTING-CONTINUED
HUPP MF510B, MF510C, MF60A-24V, MF60B-24V - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1, HEATER DOES NOT START-CONTINUED
Step 10.
Step 11.
Step 12.
Remove fuel nozzle and position container to catch fuel. Place jumper wire between
terminal No. 3 and No. 7 on terminal board. Place heater control switch on control box
panel to START. If fuel flows, turnoff heater; clean or replace nozzle. lf fuel does not
flow, clean remote filter, replace regulator valve, or inspect fuel pump. Adjust if neces-
sary.
Check for defective burner thermostat/preheater.
a.
b.
c.
Disconnect burner thermostat leads (1) and (2) from terminals 1 and 3 of ter-
minal strip (3).
Place one multimeter probe on each burner thermostat lead (1) and (2).
If multimeter indicates continuity, replace burner thermostat/preheater
(page 3-58).
Start heater (page 2-60), and watch for multimeter reading change.
If multimeter reading does not fall to zero ohms within 3 minutes replace
buner thermostat/preheater. If burner thermostat does not close in 3min-
utes, the burner thermostat maybe OK if the preheater is bad.
Check for defective preheater by placing red multimeter probe on terminal 6 of terminal
strip (3) and black probe on ground.
If multimeter reading is greater than 20 ohms, replace preheater (page 3-58).
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