Installation guide

42
VMBME102
14.3 Operational problems – Alarm
Problem – Alarm LP (low pressure pressure switch)
Cause Troubleshooting Remedy
1. Blocked strainer on the brine
circuit.
Check that the strainer is not blocked. Clean the strainer if necessary.
2. Air in the brine circuit. Listen for air in the heat pump and brine circuit. Bleed the brine circuit according to the
installation instructions.
3. Closed taps, main tap or filler
cock on the brine circuit.
Check that the shut-off cock/any other taps are
open.
Open closed taps.
4. The circulation pump for the
brine circuit is defective or has
jammed.
Check:
• That the circulation pump spins.
• That the shut-off valves are open.
• That the strainer is not blocked.
• That no air is in the heating system.
The circulation pump may have jammed, if so,
open the bleed screw and try to release the
paddle wheel using a screwdriver for example.
Open closed valves or taps.
Check, and, if necessary, clean the strainer.
If necessary, bleed the heating system accord-
ing to the installation instructions
5. Cable break or loose cable to
low pressure pressure switch.
• Check that both cables are connected on the
pressure switch.
• Using the buzzer, check that there are no cable
breaks. In order to do this, disconnect the cables
from the pressure switch and circuit board.
If a cable has come loose, connect it.
If there is a cable break, replace the cable.
6. Low pressure pressure switch
opens too
soon.
• Incorrect pressure switch installed. Higher break
pressure than intended. See marking.
• Pressure switch fault, opens at a higher pressure
than indicated (mark pressure). Check using the
manometer apparatus.
• Defective pressure switch, always open.
If the low pressure pressure switch opens too
soon or is always open, replace it.
7. Incorrect type of anti-freeze,
must be in accordance with
instructions.
Check that the correct type of anti-freeze is used. If the incorrect type of anti-freeze is used, the
entire system must be drained and refilled
with a new mixture.
8. Incorrect mix of anti-freeze, the
concentration must be in accord-
ance with instructions.
Check the freezing point of the mix using a refrac-
tometer.
If the mixture is not in accordance with the
instructions, it must be remixed in an external
container. This is because the fluids do not mix
with each other well if one is filled directly into
the system.
9. Short active collector, e.g. short
or dry bore hole, short surface soil
collector.
• Check the length of the collector that is being
used and compare with the collector length in the
dimensioning documentation.
• In addition, check that the collector is not sus-
pended ”in free air” if boreholes are used.
If the active collector is too short, the heat
pump cannot receive enough energy from the
heat source , which results in it requiring an
addition to cover the energy requirement.
10. Collector too long, pressure
drop too great.
Check the length of the collector that is being used
and that it is connected in parallel (not connected
in series) if more than 1 coil is being used.
If a longer collector is being used than recom-
mended for the specific heat pump, it must be
divided on several parallel connected coils.
11. Expansion valve defective or
incorrectly set.
Using manometer apparatus and thermometer
check what the overheating reading of the unit is.
Also check that bulb and capillary tube are undam-
aged and that the bulb is correctly installed.
If the overheating reading does not corre-
spond with the instructions for the specific
refrigerant, adjust the expansion valve until
the correct value is obtained. See separate
instructions for cooling techniques.
If overheating cannot be adjusted with the
expansion valve or if the capillary tube/bulb is
damaged, replace it.
12. Lack of refrigerant, not enough
refrigerant in the system.
Using manometer apparatus and thermometer,
check that the unit’s overheating is correct for the
specific refrigerant.
Then check in the same way that the unit’s cool-
ing is correct. See separate instructions for cooling
techniques.
If cooling is not at the correct level compared
with the specific refrigerant and is too low,
there is insufficient refrigerant in the unit.
Follow the correct procedure (depending on
type of refrigerant) to add the correct amount
of refrigerant.
If there appears to be a leak in the refrigerant
circuit, carry out leak tracing and any neces-
sary corrective action.