SECTION FOUR – Routine Maintenance and Professional Servicing
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The Heat Exchanger includes several copper-finned
tubes bent in a circular shape surrounding the
Flameholder/Burner. The number of tubes depends on
the model of heater. The ends of the tubes are expand-
ed into a steel tube sheet, which is bolted to the
Manifold Adapter (heaters built prior to 3/15/01) or
the Inlet/Outlet Manifold (heaters built after 3/15/01).
The ends of the tubes are sealed to the Manifold
Adapter with individual O-rings.
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Water flows through the Heat Exchanger Tubes, which
extract heat from the flue gases.
NOTE: The Heat Exchanger can be damaged by operat-
ing conditions like freeze-ups, improper water chemistry,
or corrosives in the vicinity of the heater. Avoid these to
keep the Heat Exchanger in good working order.
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Inspect the Heat Exchanger periodically or when operat-
ing problems occur. By removing the Flameholder, a par-
tial inspection of the inward-facing surfaces of the Heat
Exchanger can be done with a flashlight and mirror.
For a complete inspection of the Heat Exchanger,
remove it from the unit. If any one of the Heat
Exchanger tubes is damaged, replace the entire Heat
Exchanger. Repairing individual Heat Exchanger Tubes
requires special tools and procedures and should not be
attempted.
To Access the Heat Exchanger:
1. Turn off the filter pump and all electrical power to
the heater. Close the external Manual Gas Valve.
2. Remove the Upper Left and Upper Right Jackets
and disconnect the gas pipe back to the external
Manual Gas Valve.
3. Disconnect the electrical supply wires at the junc-
tion box and from the Thermistor, High Limit, AGS,
and Pressure Switch. Pull the Wiring Harness clear
of the Junction Box to allow removal of the
Combustion Chamber Cover Assembly.
4. Unscrew the seven screws holding the cover tabs to
the chamber brackets.
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4-28
Heat Exchanger
2666 1096
Heat Exchanger
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Fire or explosion hazard.
Disconnect all
power to the heater and close the External Manual
Gas Valve before starting this procedure.
Tube Sheet Coil Assembly Kit
SR/SRC200 Series: P/N 77707-0232
SR/SRC333 Series: P/N 77707-0233
SR/SRC400 Series: P/N 77707-0234
SR400HD Series: P/N 77707-0244