Sterling 6017 series installation manual Check the heater output with an

Condition	Possible cause	Solution
		Check the heater output with an
Unit does not heat.		ohmmeter to ground. It should
	Controller heater output open.	read in the mega-ohm range.
(cont’d.)		Infinite or zero readings indicate
		a defective output.
	Clogged Y strainer.	Clean Y strainer.
	Water supply to unit is turned	Open water supply.
	OFF.
	Water drain is plugged or	Clear drain line or eliminate
	excessive back pressure in
		back pressure condition.
	drain line.
Unit overheats/unable to cool.
	Heat exchanger tubes plugged	Remove tube bundles; clean/
	by lime deposits.	replace as required.
		Test solenoid valve by switching
	Faulty solenoid valve.	to Manual Cool mode and listen
		for valve operation. Replace if
		faulty.
	Leaks in connecting lines.	Inspect/replace faulty line or
		connection.
	Air in circulating lines.	Perform venting sequence in
		Chapter 3.
	Low fluid.	Check fluid level in sight glass.
		Add fluid if required.
	Defective Ful-Flo valve.	See Chapter 3.
		Drain water from low point in
Rapid drop in pressure/no	Water in fluid.	piping (see Chapter 3), or boil
		water off.
pressure.
	Vent solenoid open.	Allow vent timer to run out; or,
		check valve operation when unit
		is cold by opening the fill port.
		Check motor; rewire if
	Pump running in reverse.	necessary. See electrical
		diagrams.
	Pump repair/adjustment	Adjust head spacing or replace
	needed.	worn pump components.
	V belt broken/worn.	Replace as required.
		Drain water from low point in
Noisy pump.	Water in fluid.	piping (see Chapter 3), or boil
		water off.
	Severely degraded fluid.	Drain and flush system. Replace
		fluid.

6017 Series Hot Oil Large Temperature Control Units Page 53