Manual 2100-537
I
Page 29 of 54
SYSTEM START UP PROCEDURE FOR
GROUND WATER APPLICATIONS
1. Be sure main power to the unit is OFF at disconnect.
2. Set thermostat system switch to OFF, fan switch to
AUTO.
3. Move main power disconnect to ON. Except as required
for safety while servicing – DO NOT OPEN THE UNIT
DISCONNECT SWITCH.
4. Check system airow for obstructions.
A. Move thermostat fan switch to ON. Blower runs.
B. Be sure all registers and grilles are open.
C. Move thermostat fan switch to AUTO. Blower
should stop.
5. Fully open the manual inlet and outlet valves.
6. Check water ow.
A. Connect a water ow meter to the drain cock
between the constant ow valve and the
solenoid valve. Run a hose from the ow meter
to a drain or sink. Open the drain cock.
B. Check the water ow rate through constant
ow valve to be sure it is the same as the unit
is rated for. (Example: 6 GPM for a GTC36S2.)
C. When water ow is okay, close drain cock and
remove the water ow meter. The unit is now
ready to start.
7. Start the unit in cooling mode by moving the thermostat
switch to cool. Fan should be set for AUTO.
A. Check to see the solenoid valve opened.
8. Check the system refrigerant pressures against the cooling
refrigerant pressure table in the installation manual for
rated water ow and entering water temperatures. If
the refrigerant pressures do not match, check for airow
problem and then refrigeration system problem.
9. Switch the unit to the heat mode by moving the
thermostat switch to heat. Fan should be set for AUTO.
A. Check to see the solenoid valve opened again.
10. Check the refrigerant system pressures against the heating
refrigerant pressure table in installation manual. Once
again, if they do not match, check for airow problems
and then refrigeration system problems.
NOTE: If a charge problem is determined (high or low):
A. Check for possible refrigerant loss.
B. Discharge all remaining refrigerant from unit.
C. Evacuate unit down to 29 inches of vacuum.
D. Recharge the unit with refrigerant by weight.
This is the only way to insure proper charge.
WATER CORROSION
Two concerns will immediately come to light when
considering a water source heat pump, whether for ground
water or for a ground loop application: Will there be
enough water? And, how will the water quality affect the
system?
Water quantity is an important consideration and one which
is easily determined. The well driller must perform a pump
down test on the well according to methods described by
the National Well Water Association. This test, if performed
correctly, will provide information on the rate of ow and
on the capacity of the well. It is important to consider the
overall capacity of the well when thinking about a water
source heat pump because the heat pump may be required to
run for extended periods of time.
The second concern, about water quality, is equally
important. Generally speaking, if the water is not offensive
for drinking purposes, it should pose no problem for
the heat pump. The well driller or local water softening
company can perform tests which will determine the
chemical properties of the well water.
Water quality problems will show up in the heat pump in
one or more of the following ways:
1. Decrease in water ow through the unit.
2. Decreased heat transfer of the water coil (entering to
leaving water temperature difference is less).
There are four main water quality problems associated with
ground water. These are:
1. Biological Growth. This is the growth of microscopic
organisms in the water and will show up as a slimy
deposit throughout the water system. Shock treatment
of the well is usually required and this is best left up
to the well driller. The treatment consists of injecting
chlorine into the well casing and ushing the system
until all growth is removed.
2. Suspended Particles in the Water. Filtering will
usually remove most suspended particles (ne sand,
small gravel) from the water. The problem with
suspended particles in the water is that it will erode
metal parts, pumps, heat transfer coils, etc. So long
as the lter is cleaned and periodically maintained,
suspended particles should pose no serious problem.
Consult with your well driller.
3. Corrosion of Metal. Corrosion of metal parts results
from either highly corrosive water (acid water, generally
not the case with ground water) or galvanic reaction
between dissimilar metals in the presence of water. By
using plastic plumbing or dielectric unions, galvanic
reaction is eliminated. The use of corrosion resistant
materials such as the Cupronickel coil through the water
system will reduce corrosion problems signicantly.
