AERCO Electronic Controls System (ECS) - Manual (Page 36)

Electronic Control System (ECS) and Type CXT-E Valve
6. ROUTINE MAINTENANCE
Page 36 of 82
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 VD2: 02/28/14
OMM-0003_0D AC-105
6.3 ELECTRONIC CONTROL SYSTEM (ECS) ROUTINE
MAINTENANCE
6.3.1 Quarterly Maintenance:
Every three months, check the operation of the Over-Temperature Switch as follows:
WARNING
THIS PROCEDURE WILL RELEASE HOT WATER. TAKE APPROPRIATE
PRECAUTIONS TO AVOID BURNS.
1) Refer to Section 3 (ADJUSTMENTS) and lower the Over Temperature setting to
approximately 5°F below the present Setpoint shown in the lower display of the
Temperature Controller.
2) Verify that an Over-Temperature Alarm is generated and the following events occur:
• The CXT-E Control Valve closes.
• The Over-Temperature Solenoid (located at top of Heater) opens and expels water from
the system.
• The Over-Temperature Switch generates an audible alarm.
3) Following successful completion of the Over-Temperature Alarm check, return the Over-
Temperature Switch setting to its original Over-Temperature setting.
6.3.2 Annually:
Once each year, AERCO recommends that the Temperature Sensor(s) and Flow Sensor be
checked to ensure there is no scale build-up or clogging that may degrade system operation.
Proceed as follows:
1) Close the upstream and downstream water supply valves to the Heater.
2) For Water-to-Water Heaters (E-Plus or Double-Wall) where hot boiler water is the heating
fluid, turn off the inlet and outlet valves in the fluid lines.
3) Check the Temperature Sensors and Flow Sensor as described in the following paragraphs
and steps. Upon completion of the Annual checks, restore the Heater to operation by
opening all valves which were closed in steps 1 and 2 above.
6.3.3 Temperature Sensors:
The Heater contains a Dual Temperature Sensor in the Heater outlet port. In addition, Water to
Water Heaters (E-Plus or Double-Wall) using hot (boiler) water as the heating fluid also contain
single-Element Sensors in the heating fluid inlet and outlet lines. Check and, if necessary, clean
these items by performing the following step:
1) Disconnect and remove the Dual Temperature Sensor (Thermocouple) at the Heater outlet
and inspect for evidence of scale buildup on the stainless steel sleeve. If necessary, clean
the sensor using a wire brush.
2) For Water-to-Water Systems, repeat step 1 for the Single-Element Sensors in the heating
fluid inlet and outlet lines.
3) After cleaning, reinstall the sensor(s) and ensure they are securely tightened.
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