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Model SCM Air to Water Heat Pump — Installation, Operation & Maintenance Manual
Perform Annual Inspection
Glycol/water mixture
The water system must contain a mixture of
inhibited glycol and water with thermal protection
sufcient for the coldest expected temperature for
the installation. The inhibitor level can degrade over
time, and may need to be adjusted periodically. The
inhibitor is essential to prevent the glycol from
accelerating corrosion of metal components in the
system. The glycol and inhibitor levels must be
checked regularly (no less than once annually).
The minimum allowable concentration of glycol is
10% by volume in all installations.
Automotive glycol is not suitable for use in the heat
pump system. Over time it may leave deposits
which will degrade heat pump performance and
damage pumps or other devices in the system.
Use only ethylene glycol or propylene clycol
mixtures specically labeled for boiler or hvac use.
1. At least once annually, sample the system uid to verify that
the glycol concentrations meets the minimum value given in
Figure 12. Also test the inhibitor concentration. Add glycol
and inhibitor as needed to return the system to the correct
concentrations.
2. Perform any and all other tests as recommended by the
anti-freeze manufacturer’s instructions in order to ensure
optimal performance and maintain warranty protection on all
installed components.
Check operating pressure
1. Check the glycol/water system pressure. Operating pressure
should be between 15 and 25 PSIG. Adjust uid volume if
needed to restore pressure.
2. If pressure is low, check system for evidence of leaks. Repair
all leaks immediately.
Perform annual inspection
Electrical shock hazard — Disconnect all electrical
power before proceeding with the following.
1. At least once annually, perform a complete inspection of the
system, including at least the following.
2. Inspect the SCM for signs of dirt or debris accumulation. Re-
move any debris and notify the building owner that the unit
must be kept clean and unobstructed.
3. Inspect glycol/water system piping and components. Repair
or replace any defective components. Repair all leaks im-
mediately.
4. Close the isolation valves on either side of the y-strainer at
the SpacePak heat pump return connection. Remove the
screen and inspect for sediment. Clean if necessary.
• If the strainer has become clogged with sediment,
determine whether the system needs to be drained,
cleaned and re-lled. Excessive sediment accumulation
in the strainer will reduce ow and cause the unit to shut
down.
5. Inspect all wiring and wiring connections. Tighten connec-
tions if needed. Correct any problems found.
6. Check the fuses or breakers to ensure they are correctly
sized and properly installed.
7. Clean the SCM heat exchangers and air openings.
8. Cycle the system on heating and cooling. Verify that all com-
ponents operate correctly.
Preparing the SCM for shut down
DO NOT turn off power to the SCM heat pump in
the winter or any time when there is a possibility of
freezing. Power must be ON for the automatic anti-
freeze operation to occur. See information below for
preparing the unit for shut down.
1. When the water temperature drops below 34°F during
periods of non-use, the pump will start and the antifreeze
heater (optional, when installed) will energize and continue
to operate until the temperature reaches 38°F.
2. If SCM must be turned off or left idle during periods when
freezing is possible, one of the following must be done:
a. Verify that sufcient glycol solution is present to protect
against most extreme anticipate conditions
b. — OR — Drain heat pump and external piping completely
To restart after shutdown
1. If unit was drained, rell.
2. Follow start up procedure from Section 8.
Section 11: Annual Maintenance
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