Troubleshooting
18
309524V
Troubleshooting
Problem
Cause
Solution
Heater will not heat.
No current.
Check circuit and fuses.
Check continuity of primary thermo-
stat (24), backup thermostat (10),
and thermal limit sensor (15).
Check continuity of thermostat (10)
and heater block (3) terminals - Page
19.
Burned out heater block (3).
Replace block - Page 21.
Blown heat limiter (15).
Check continuity of primary thermo-
stat (24) and backup thermostat (10).
Replace thermostats if necessary
when replacing thermal limit sensor
(15) - Pages 19-21.
Temperature too low.
Fluid requires more warm-up time.
Increase warm-up time.
Wrong temperature setting.
Adjust setting - Page 16.
Flow rate too high.
Reduce flow rate or use 2 heaters.
Clogged fluid passages.
Flush regularly - Page 17.
Temperature too high.
Wrong temperature setting.
Adjust setting - Page 16.
Failed primary thermostat (24).
Replace - Page 19.
High fluctuating temperatures, about
220-250°F (104-120°C) at 0.1 GPM.
Primary thermostat (24) contacts
sticking.
Replace thermostats (24, 10) - Page
19. Note that backup thermostat (10)
keeps heater functioning for only a
short time.
Too much pressure drop or fluid will
not flow.
Flow rate too high.
Reduce flow rate or use 2 heaters.
Clogged fluid passages.
Flush regularly - Page 17.
Heater fittings leak.
Loose or damaged fittings.
Tighten fittings or replace heater
block - Page 21.
F
IG
. 14: Electrical Schematic
53
3
24
37
10
11
37
15
L2
GND
L1
J3 = 120 VAC
J2 = 200/240 VAC
J1 = 380/480 VAC
WHITE
BLACK
BLACK
BLACK
WHITE
WHITE
BLOCK, HEATER
BLACK
ti31122a
