15
while maintaining the full nitrogen flow rate into the liquid
line. Continue to blast the full nitrogen flow until the sand
or dirt is removed from the tubing.
notE:
If the dry nitrogen purge is not successful in removing
the debris, flush the tubing with one to two (depending on
severity of debris) full large bottles of RX-11. This is done by
attaching the RX-11 bottle to the liquid line of the sub-surface
refrigerant tubing, turning the RX-11 bottle upside down,
and opening the valve all the way. Let the entire bottle flow
through the sub-surface tubing. Use only approved RX-11
recovery procedures when evacuating the refrigerant.
6. Remove the temporary valves and reconnect the liquid and
vapor lines.
7. Evacuate and weigh in the correct initial charge listed in
8. Continuously operate the system in the cooling mode for
at least one full hour, so that any remaining debris will be
washed up with the liquid refrigerant. If there is more than
a 3° F differential, install a new filter/dryer in the liquid line
assembly as often as necessary until there is less than a
3° F differential.
9. Operate the system in 24 hour segments, changing the filter/
dryer as often as necessary until there is no more than a
3° F differential across the filter/dryer.
notE:
The filter/dryer may be changed by isolating the
air handler segment using the shut-off valves inside the
compressor unit.
operating pressures are too high or too low
(above 375 psig on the High pressure Side and
80 psig or less on the Low Pressure (Suction)
Side)
• During heating to cooling transition, the system pressure
may initially drop below 80 psig but should rise back to
correct operational levels. This event is normal for this
system. During cooling to heating transition, the discharge
pressure may initially rise above 375 psig but should drop
back to correct operational levels.
• Check the filter/dryer in the liquid line assembly. Verify there
is no more than a 3° F temperature differential. See filter/
.
• Check the pressures across the oil separator to determine
if the filter within the oil separator is dislodged or clogged.
• Check charge level as detailed in the Starting In Heating
Mode & Charging To Sight Glass section (page 10).
the system Doesn’t supply Warmed air In the
Winter or cooled air In the summer
• Check system operational pressures for a potential
refrigerant leak (operational pressures will be too low).
notE:
If pressures are too high in the summer, or too low
in the winter, the geothermal heat pump exchange field
may have been overstressed. This can be accomplished
by either turning the system off (use your supplemental
back-up heating during the winter), for only one 24 hour
period, or by adjusting the thermostat setting to a higher
than normal setting during the summer and to a lower than
normal setting during the winter (usually for several days).
• When pressures return to normal levels, field return refrigerant
temperature returns to normal operational temperatures, air
supply temperatures return to normal levels, and extended
system operational times return to normal, the field has
recovered and the temperature settings may be returned
to their preferred levels.
the compressor unit Will not start
• Check the time delay on the control board (in the electrical
box) inside the compressor unit.
the unit will not start
until the set time delay period (5 minutes) has expired
:
after an electrical outage, after a breaker is turned back on,
after switching from heating to cooling or vice versa, etc.
• The time delay period may not have expired, or the control
board may be malfunctioning.
• Some air handlers may have an internal start delay that will
effectively prevent total system operation until the delay
time has expired.
the system Will not Maintain the thermostat
set Point
• Check the system charge, head and suction pressures, and
air handler entering/exiting air temperature differentials. For
additional charging instructions, see
• Check for restrictions in the airflow. Are filters dirty and/or
is the air return blocked by furniture? Check the thermostat
also.
• Check the emergency back-up heat for proper functioning
if the exterior weather is below design temperatures.
• Check the return air ducts for leaks and make sure the air
handler ductwork is tightly sealed. An improperly sealed
air handler in an unconditioned area will directly pull in
unconditioned air and overstress the system.
the supply temperature Is too cold
Below 90° F In Heating Mode
• The system has been over-stressed beyond design
parameters.
• The system has been undersized.
• The CFM and/or the fan setting for the interior air handler
is too high.
notE:
This is a very common occurrence, as
the fan speed may have been set on high.
