AERCO SWDW68 U-Tube Double-Wall Heaters w/ECS - Manual (Page 51)

HE-
111 − TROUBLESHOOTING
Rev B Mar 2013 7-9
Table 7-2. TROUBLESHOOTING – ELECTRONIC CONTROL VALVE CXT-E, continued
NO. FAULT INDICATION PROBABLE CAUSE CORRECTIVE ACTION
T13 Wide variations in heat
exchanger outlet
temperature during wide
flow variations.
1. Mixed water temperature sensor
is malfunctioning.
2. Recirculation pump is
malfunctioning.
1. Refer to Table 7-3 Item T21, and check the operation of the mixed
water temperature sensor.
2. Proceed as follows:
a. Check input power to the recirculation pump.
b. Check the temperature of the copper tube above the pump. It
should be the same as the outlet DHW temperature. If cold,
repair or replace the pump, as required.
T14 Rapid fluctuations in heater
outlet temperature which
do not follow load changes
1. Temperature Controller is
malfunctioning.
2. Steam Trap or orifice fault
1. Refer to Table 7-3, Items T16 and T19 to troubleshoot the
Temperature Controller.
2. Refer to T12, Corrective Action 4 above and proceed as directed.
T15 System not operating. All
displays are blank.
1. External 120 VAC power is
disconnected.
2. Defective ON/OFF power switch
on Control Box.
1. Ensure that the external circuit breaker is ON. Check for 120 VAC
power across TB-2 terminal leads 101 (Line) and 102 (Neutral).
2. Set ON/OFF power switch to the ON (Up) position and verify that the
switch indicator lights. Also:
a. Verify that 120 VAC is present across TB-2 terminal leads 100
(Line) and 102 (Neutral).
b. If voltage is not present, replace theON/OFF power switch.
T16 Love Over-temperature
Switch display is blank.
Defective DC Power Supply Disconnect the DC output connector on the left internal wall of the
Control Box (Figure 8-12b). Verify that 24 VDC is present across the V+
and V- terminals. If 24 VDC is not present, replace the DC Power Supply.
T17 Hot Water Output
temperature consistently
above setpoint by 10°F, or
more. However,
temperature is below over-
temperature limit setting. 1. Temperature Controller is not set
properly.
2. Faulty Temperature Sensor
(thermocouple) is connected to
Temperature Controller.
3. Valve Actuator is not properly
secured to the linkage assembly.
4. Polarity of J-Thermocouple
connection is reversed. [Should
be Red (-) White (+)]
1. Refer to Chapter 4 Adjustments and check current setting of
Temperature Controller. Readjust as necessary.
2. Verify that Hot Water Outlet Temperature Sensor is securely
connected to the cable plug. Replace the DHW Outlet Temperature
Sensor, if necessary.
3. Verify that the Actuator is securely fastened to the linkage assembly.
Tighten as needed and readjust the CXT-E Control Valve per
Chapter 4.
4. Check polarity of J-Thermocouple connection. Correct, if necessary.