AERCO KC1000 Heater w/Mod-Box Controller - Manual (Page 36)

MAINTENANCE
31
6.7 BTU TRANSMITTER ASSEMBLY
The BTU Transmitter is a crucial part of the
unit’s temperature control system. It must be
inspected and kept free of scale and debris in
order for the unit to maintain accurate outlet
water temperatures.
To inspect the transmitter:
1. Place the ON\OFF switch in the OFF
position.
2. Remove the sheet metal covers from the
unit.
3. Shut the water inlet, outlet and recirculation
valves to the unit.
4. Open the drain valve on the unit.
5. Slowly open the pressure relief valve to allow
air-flow into the unit.
6. Drain the unit until the WATER LEVEL
FAULT LED is illuminated. Drain slightly
more, then release the relief valve and close
the drain valve on the unit.
7. Disconnect electrical power to the unit.
8. Close the 3 ball valves on the BTU
transmitter, (See Fig. 6.3).
Figure 6.3
Ball Valve Locations
9. Remove the 4 screws holding the BTU
transmitter pump to the impeller housing.
Remove and set the pump aside, (See Fig.
6.4).
NOTE:
It is not necessary to disconnect the
electrical wires to the pump
Figure 6.4
BTU Transmitter Pump Disassembly
10. Using a 5/8” and 9/16” wrench loosen the 4
compression fittings holding the lower tubing
assembly in place, (See Fig. 6.5)
Figure 6.5
Compression Fitting Locations
11. Carefully remove the lower tubing assembly
taking care not to lose either the cold water
or hot water mixing orifice, (See Fig. 6.6).