Graco 309524N important safety instructions Troubleshooting, Problem Cause Solution

Troubleshooting

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
		18.
	Burned out heater block (3).	Replace block - Page 20.
	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 18-20.
Temperature too low.	Fluid requires more warm-up time.	Increase warm-up time.
	Wrong temperature setting.	Adjust setting - Page 15.
	Flow rate too high.	Reduce flow rate or use 2 heaters.
	Clogged fluid passages.	Flush regularly - Page 16.
Temperature too high.	Wrong temperature setting.	Adjust setting - Page 15.
	Failed primary thermostat (24).	Replace - Page 18.
High fluctuating temperatures, about	Primary thermostat (24) contacts	Replace thermostats (24, 10) - Page
220-250°F (104-120°C) at 0.1 GPM.	sticking.	18. Note that backup thermostat (10)
		keeps heater functioning for only a
		short time.
Too much pressure drop or fluid will	Flow rate too high.	Reduce flow rate or use 2 heaters.
not flow.
	Clogged fluid passages.	Flush regularly - Page 16.
Heater fittings leak.	Loose or damaged fittings.	Tighten fittings or replace heater
		block - Page 20.

R

OFF	230°F
	(110°C)

	300°F	a1
F
	(149°C)
	e2

FIG. 14: Electrical Schematic

Mp SL

e1 255°F (124°C)

R6-55 ohm

05556-524

309524N 17