Quick Start Manual
42
Installation, Operation & Maintenance  HTV/HTD/HTH SERIES  Heat Controller, Inc.
Preventive Maintenance
Water Coil Maintenance
(Direct ground water applications only) - If the system is installed 
in an area with a known high mineral content (125 P.P.M. or 
greater) in the water, it is best to establish a periodic maintenance 
schedule with the owner so the coil can be checked regularly. 
Consult the well water applications section of this manual for a 
more detailed water coil material selection. Should periodic coil 
cleaning be necessary, use standard coil cleaning procedures, 
which are compatible with the heat exchanger material and 
copper water lines. Generally, the more water fl owing through 
the unit, the less chance for scaling. Therefore, 1.5 gpm per ton 
[2.0 l/m per kW] is recommended as a minimum fl ow. Minimum 
fl ow rate for entering water temperatures below 50°F [10°C] is 2.0 
gpm per ton [2.6 l/m per kW].
Water Coil Maintenance
(All other water loop applications) 
Generally water coil maintenance is not needed for closed loop 
systems. However, if the piping is known to have high dirt or 
debris content, it is best to establish a periodic maintenance 
schedule with the owner so the water coil can be checked 
regularly. Dirty installations are typically the result of deterioration 
of iron or galvanized piping or components in the system. 
Open cooling towers requiring heavy chemical treatment and 
mineral buildup through water use can also contribute to higher 
maintenance. Should periodic coil cleaning be necessary, use 
standard coil cleaning procedures, which are compatible with both 
the heat exchanger material and copper water lines. Generally, 
the more water fl owing through the unit, the less chance for 
scaling. However, fl ow rates over 3 gpm per ton (3.9 l/m per kW) 
can produce water (or debris) velocities that can erode the heat 
exchanger wall and ultimately produce leaks.
Hot Water Generator Coils
See water coil maintenance for ground water units. If the potable 
water is hard or not chemically softened, the high temperatures 
of the desuperheater will tend to scale even quicker than the 
water coil and may need more frequent inspections. In areas with 
extremely hard water, a HWG is not recommended.
Filters
Filters must be clean to obtain maximum performance. Filters 
should be inspected every month under normal operating 
conditions and be replaced when necessary. Units should never 
be operated without a fi lter. 
Washable, high effi ciency, electrostatic fi lters, when dirty, can 
exhibit a very high pressure drop for the fan motor and reduce 
air fl ow, resulting in poor performance. It is especially important 
to provide consistent washing of these fi lters (in the opposite 
direction of the normal air fl ow) once per month using a high 
pressure wash similar to those found at self-serve car washes.
Condensate Drain
In areas where airborne bacteria may produce a “slimy” 
substance in the drain pan, it may be necessary to treat the drain 
pan chemically with an algaecide approximately every three 
months to minimize the problem. The condensate pan may also 
need to be cleaned periodically to insure indoor air quality. The 
condensate drain can pick up lint and dirt, especially with dirty 
fi lters. Inspect the drain twice a year to avoid the possibility of 
plugging and eventual overfl ow. 
Compressor
Conduct annual amperage checks to insure that amp draw is no 
more than 10% greater than indicated on the serial plate data.
Fan Motors
All units have lubricated fan motors. Fan motors should never be 
lubricated unless obvious, dry operation is suspected. Periodic 
maintenance oiling is not recommended, as it will result in dirt 
accumulating in the excess oil and cause eventual motor failure. 
Conduct annual dry operation check and amperage check to 
insure amp draw is no more than 10% greater than indicated on 
serial plate data.
Air Coil
The air coil must be cleaned to obtain maximum performance. 
Check once a year under normal operating conditions and, if 
dirty, brush or vacuum clean. Care must be taken not to damage 
the aluminum fi ns while cleaning. CAUTION: Fin edges are sharp.
Cabinet
Do not allow water to stay in contact with the cabinet for long 
periods of time to prevent corrosion of the cabinet sheet metal. 
Generally, vertical cabinets are set up from the fl oor a few inches 
[7 - 8 cm] to prevent water from entering the cabinet. The cabinet 
can be cleaned using a mild detergent.
Refrigerant System
To maintain sealed circuit integrity, do not install service gauges 
unless unit operation appears abnormal. Reference the operating 
charts for pressures and temperatures. Verify that air and water 
fl ow rates are at proper levels before servicing the refrigerant 
circuit.










