AERCO SWDW68 U-Tube Double-Wall Heaters w/ECS - Manual (Page 43)

Rev B Mar 2013 7-1
CHAPTER 7 TROUBLESHOOTING
7.1 INTRODUCTION
This section provides you with troubleshooting procedures for isolating faults to the most probable cause
whenever malfunctions occur in the heat exchanger (Table 7-1), CXT-E Electronic Control Valve
(Table 7-2), or Electronic Control System (ECS; Table 7-3). Table 7-4 provides troubleshooting tips for
correcting control system faults, and Table 7-5 provides the dynamic temperature control settings for the
three models of the DW-Series water heater product line.
Before performing the troubleshooting steps and procedures provided in Tables 7-1 through 7-4, complete
the following preliminary checks:
1. ELECTRONIC CONTROL VALVE, CXT-E
a. Verify that all piping connections have been made in accordance with Figure 2-4 and that all
electrical connections have been made in accordance with Figure 2-7.
b. Ensure that the Electronic Control Valve (“Valve”) is installed with the flow arrow on the Valve
body pointing in the direction of flow.
c. Ensure that both the upstream and downstream shutoff valves are fully open.
2. ELECTRONIC CONTROL SYSTEM
a. Ensure that all ECS electrical cable connections are secure.
b. Ensure that the CXT-E Control Valve actuator is connected to the Control Box cable plug.
NOTE
When system malfunctions occur, check the troubleshooting sections of the manuals
for any other equipment included in this installation, as necessary, in addition to the
procedures provided in this section. Appendix A of this manual contains process fault
and diagnostic alarm information for the Eurotherm, Model 2408 Temperature
Controller.
7.2 TROUBLESHOOTING PROCEDURES
When a heat exchanger fault occurs, proceed as follows:
1. Refer to the FAULT INDICATION column in the following tables and locate the fault that best describes
the existing conditions.
2. Proceed to the PROBABLE CAUSE column. If more than one item is listed, start with the first item
shown for the fault condition.
3. Perform the corresponding checks and procedures listed in the CORRECTIVE ACTION column for the
first PROBABLE CAUSE.
4. Continue checking each additional PROBABLE CAUSE for the existing fault until the fault has been
corrected.
5. If component removal and/or replacement is required, refer to the applicable procedures in Chapter 8
Corrective Maintenance.