9. Too much cooling.
10. “Sweating.”
11. Blowers won’t operate on Heat.
12. Equipment is noisy.
13. Insufficient or no heat.
a. Thermostat set too low.
b. Defective thermostat
a. Condensate drain from evaporator to condenser
plugged.
b. Insulating seals on equipment damaged.
c. Evaporator blower motor not up to speed.
d. Evaporator blower incorrectly positioned.
a. No power.
b. Heat is off (equipment with heat fan lock out).
c. Faulty push-button switch.
d. Loose connections at push-button switch.
e. Thermostat set too low.
a. Blower rubbing against enclosure.
b. Blower motor bearings dry.
c. Loose blower hold-down nuts on motor-bracket
assembly
d. Refrigerant absorbed in compressor oil after extended
shutdown.
e. Equipment improperly installed.
f. Damper solenoid hums.
g. Loose terminal box cover on side of compressor.
h. Loose electrical components.
i. Copper tubing vibrating.
j. Harmonics.
a. No steam or hot water being applied.
b. No power.
c. Faulty push-button switch.
d. Loose connection at push-button switch.
e. Thermostat set too high.
f.
Thermostat faulty.
g. No power output on transformer secondary.
h. Inoperative valve.
1) Steam valve N/C.
2) Hot water valve N/C.
a. Adjust.
b. Replace.
a. Remove obstructions to water flow.
b. Adjust or replace.
c. Check for correct voltage. Replace motor if necessary.
d. Tighten.
a. See No. 1.
b. Open heat valve or turn on heating system.
c. Replace.
d. Tighten.
e. Adjust. Rotate control knob to “warmer”.
a. Adjust fan position on motor shaft or reposition fan
motor bracket assembly.
b. Replace motor.
c. Align blower assembly and tighten nuts.
d. Noise will disappear after equipment runs awhile.
e. Make necessary adjustments to components.
f. Check for proper adjustment. Apply silicone oil or
grease to gap between solenoid and armature.
g. Tighten.
h. Fasten securely.
i. Occasionally equipment will have noise for no ap-
parent reason. Inspection has revealed no loose
components that might be the source of the noise.
Due to the action of the compressor, it is possible to
have internal noise develop if the refrigerant tubing has
become bent even slightly. To distinguish this condition
from the simple rattle producing vibration caused by
loose screws, nuts and other components, grasp the
refrigerant tubing at various points throughout the sys
-
tem until a point is found where the noise is eliminated
or reduced. Bend the copper
tubing very gently until the noise disappears.
j.
Tighten.
a. Contact building management.
b. Check power supply line fuse, circuit breakers. Blown
fuses would indicate circuit overloading, a short circuit,
or a grounded condition in the circuit.
c. Replace.
d. Replace wire or tighten.
e. Adjust. Rotate knob to “warm.”
f.
Replace.
g. Replace.
h.
1) Temporarily lock valve open; replace.
2) Replace.
Troubleshooting
These items should be checked by a qualified service technician only.
Trouble
Cause
Cure
Notes:
This guide was prepared with standard equipment in mind. If equipment is special, it may not be entirely applicable.
* If equipment is still in warranty.
**
Note:
Before trying to correct the noise, determine its cause such as conditioned air blower, compressor or condenser blower. Operate the
conditioned air blowers only. If this doesn’t cause the noise, operate on cooling. Then disconnect one compressor lead. If the noise stops, the
compressor is the source, If not, it is caused by the condenser blower.
©2008 McQuay International • www.mcquay.com • 800-432-1342
IM 882 / Page 36 of 36 (Rev 1-08)
®
This document contains the most current product information as of this printing. For the most up-to-date
product information, please go to
www.mcquay.com.
