AERCO SWDW68 U-Tube Double-Wall Heaters w/ECS - Manual (Page 47)

HE-
111 − TROUBLESHOOTING
Rev B Mar 2013 7-5
Table 7-1. TROUBLESHOOTING – HEAT EXCHANGER, continued
NO. FAULT INDICATION PROBABLE CAUSE CORRECTIVE ACTION
T5 Excess or insufficient
condensate being
returned from the heat
exchanger 1. There is a leak in either the inside or outside wall of
one or more of the heat exchanger tubes, as
indicated by a flow from the leak detection port.
2. Condensate is backing up into the heat exchanger
because of a restriction in the condensate drain
line, such as an undersized or faulty trap.
3. The condensate return piping has not been
installed so as to enable the condensate to drain
freely by gravity, and/or the condensate check
valve leaks or has failed.
1. Refer to Section 9.2 and proceed as instructed.
2. Check AERCO or the nearest AERCO Representative for
the trap size required and make the necessary correction
3. If necessary, rearrange the condensate return piping to
permit condensate to drain freely from the heat exchanger
connection. Inspect the check valve and replace it if it is
leaking or has failed. Also, check to make sure that there is
no restriction in the condensate drain line.
T6 Steam being
discharged from heat
exchanger at too high
a temperature The heat exchanger tubes are scaled up. Contact AERCO or your nearest AERCO Representative for
advice concerning the required remedy.
T7 Pressure/temperature
relief valve pops 1. Static pressure of the Cold Water is too high.
2. Fluid to be heated is preheated too hot.
3. Leaking valve in by-pass line, if any, around the
Control Valve.
4. Lack of expansion capability in the hot water
system.
5. Insufficient shock absorbers.
6. The Control Valve does not close.
7. The Over-temperature Limit Switch is out of
adjustment, or some component of the system has
failed.
1. Make corrections necessary to bring the pressure below the
relief valve setting.
2. Reduce the preheating to a temperature at least 10°F
below the desired Hot Water Output temperature.
3. Maintain the valve to shut tight.
4. Insert an expansion tank in the Hot Water Output line near
the heat exchanger.
5. Insert shock absorbers (water hammer arrestors) in both
the cold and hot water systems, as needed to eliminate
shock waves.
6. Check the instructions in Table 7-2.
7. Check the Over-temperature Limit Switch setting and adjust
to the specified setting (usually 20°F higher than the
desired Hot Water Output temperature) (See 4.3.2). Inspect
and repair or replace each component as necessary.