Cleaning The Heat Exchanger; Mechanical Cleaning Of The Heat Exchanger - Watts AERCO EXT Installation, Operation & Maintenance Manual

Modulex EXT Commercial Series
CHAPTER 8: Maintenance Schedule

8.12 Cleaning The Heat Exchanger

Over time, hard combustion by-product deposits can form on the combustion chambers' heat
elements. Routine maintenance may be sufficient to keep these elements clean. However, if the
by-product build-up is too great the unit's overall efficiency will decline.
If an inspection of the heat exchanger reveals a build-up of combustion by-product deposits,
clean the heat exchangers mechanically (section 8.12.1) and, if necessary, with a chemical
cleaning solution specifically designed for aluminum heat exchangers (section 8.12.2).
The instructions below should remove most of the by-product buildup. It will also loosen some of
the buildup that remains, which the boiler will then shed during normal operation.

8.12.1 Mechanical Cleaning of the Heat Exchanger

1. Use a stiff, plastic-bristled brush to remove larger deposits from the heat exchanger rods.
Try to remove all large deposits. The lower rods, being closer together, are harder to reach.
It won't be possible to reach all rows of pins, however a combination of different sized
brushes may be useful.
Figure 8-21: Modulex Heat Exchangers – Cut-Away View
C A U T I O N !
Use only plastic-bristled brushes, not wire brushes, during cleaning. Wire brushes could damage
the surface of the aluminum heat exchanger rods.
2. Wash the combustion chamber underneath with water. Avoid getting the electrical
harnesses and components wet. During this operation, inspect the condensate drain pipe
to determine if it is free of obstructions; wash water should drain freely from the condensate
drain pipe.
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