SMB Air Conditioner
12 VDC Owner’s Manual 9/09
Page 9 of 13
PROBLEM/SYMPTOM
LIKELY
CAUSE(S)
CORRECTION
Unit provides
insufficient cooling.
1. Restriction in water
system.
2. Water pump.
3. Air filter.
4. Indoor coil.
5. Ice on indoor coil.
6. Unit is undersized
7.Low refrigerant
1. Strainer or thru-hull fitting are clogged. Clean and
check for water flow. Make sure seacock (ball
valve) is open.
2. Check for electrical shorts, ground and open
circuits. Replace water pump if it is defective.
Replace water pump if it is undersized.
3. Clean or replace the air filter if it is dirty.
4. The indoor coil may require cleaning if the unit
was operated without a filter.
5. Thermostat setting is too low. Shut down unit until
ice has melted and restart at a higher temperature
setting.
6. Check if the unit is undersized for the load.
Replace with larger unit or add additional unit(s) if
necessary.
7. Add refrigerant
Noise operation.
1. Copper tubing is
vibrating.
2. Indoor blower assembly.
3. Loose cabinet or
components.
4. Improper unit
installation.
1. Adjust by bending slightly to a more stable
position. Separate any tubing that is making
contact with other tubing or components.
2. If blower wheel is hitting housing, adjust the wheel
position in the housing. Replace blower motor or
assembly if the bearing(s) are defective.
3. Check and tighten loose screws.
4. Make sure unit is level and secure to deck.
Water is leaking from
unit.
1.
Condensate
pan.
2. Condensate drain line
or pump.
3. Loose fittings or
connections.
1. Check for leaks and repair as required.
2. Check for leaks and repair as required.
3. Tighten fittings and connections. Check the
condensate drain line for leaks.
Electrical shock at unit. 1. Electrical component is
shorted to ground.
1. Check control board, blower motor, compressor
and pumps with an ohmmeter or high potential
tester. Determine what is grounded and replace
or rewire.
2. Line trip is too sensitive
