Troubleshooting Guide

Proper cooler maintenance (pre-season start-up, seasonal care and winterizing) will assist in minimizing evaporative cooler problems. Some of the most common evaporative cooler problems are listed below. After identifying the problem, read across the page to find the probable cause and the appropriate solution. Replacement parts can be found easily and inexpensively wherever coolers are sold and serviced. Troubleshooting and service to the evaporative cooler should be performed by qualified personnel only.

Rules of Safety

  1. Disconnect electrical power at the fuse or breaker box and remove the motor and pump plug from the junction box before you begin installation or servicing your cooler.
  2. Installation of your cooler must conform to local codes and utility standards. The staff of experts at Dial Manufacturing are ready to help you with any questions that you may have in this regard.
  3. Wear rubber-soled shoes when working on the roof of your house.
  4. Make sure the mounting surface on your roof will support the weight of your cooler.
  5. Don’t install or service your cooler during rain or high wind weather conditions.
  6. Keep your children a safe distance from where you are working.
  7. If you work with power tools, wear protective eyewear and gloves.
  8. Have adequate means to raise the cooler to the roof to prevent damage to the cooler and injury to yourself. Removing the pad frames from the cooler prior to raising it to the roof can make the job much easier.
  9. Never drain your cooler onto the roof. Use a hose connected to the drain fitting to drain the water off the roof. Water residue could stain your roof or cause you to slip.
  10. Always use the right tools.

Caution: If motor has stopped running due to overheating, turn motor OFF prior to work on the evaporative cooler to avoid an unexpected motor start up.
Important: When performing troubleshooting tasks on any electrical parts, always turn the electricity OFF prior to assembly and disassembly of these items.

ProblemPossible Cause(s)Solution(s)
A. Motor cycles on and off (starts and stops).A.1. Motor pulley diameter too large.A.1.1. For variable diameter motor pulleys: Use an ammeter to properly set pulley diameter until motor current draw is approximately equal to, but not greater than, the motor current nameplate reading. If an ammeter is not available, continually open the pulley diameter 1/2 turn at a time until motor no longer cycles on and off. Cooler installations with little to no ducting may require opening pulley up to 5 turns. Cooler installations with multiple ducts may require opening pulley 2 1/2 (or more) turns.

Recommended adjustable pulley sizes:
3 1/4" O.D. for 1/3 H.P.
3 1/2" O.D. for 1/2 H.P.
3 3/4" O.D. for 1/2 & 3/4 H.P.

A.1.2. For fixed diameter motor pulleys: Check owners manual for proper pulley size. Replace if needed.
A.2. Belt tension too tight.A.2.1. Adjust motor mounting bracket so that a 3 lb. force will deflect the belt 3/4" to 1".
A.3. Blower bearings too tight.A.3.1. Oil blower bearings. Replace bearings if necessary.
A.4. Loose electrical connection.A.4.1. Check connections and tighten where needed.
B. Motor ran once, but now won't turn on and its casing is hot.B.1. Motor pulley diameter too large.See solution A.1.1 & A.1.2.
B.2. Belt tension too tight.See solution A.2.1.
C. Motor hums, but does not run and its casing is hot.C.1. Motor pulley diameter too large.See solution A.1.1 & A.1.2.
C.2. Belt tension too tight.See solution A.2.1.
D. Motor does not turn on.D.1. Bad wall switch.D.1.1. Replace wall switch.
D.2. Bad thermostat.D.2.1. Replace thermostat.
D.3. Bad electrical connection(s).D.3.1. Check for damaged electrical cord. Replace if needed.

D.3.2. Check for tripped circuit breaker.

D.3.3. See solution A.4.1.
E. Motor runs but no air enters house.E.1. Duct damper blocking air.E.1.1. Remove damper.
F. Motor runs but not enough air enters house.F.1. Inadequate exhaust ventilation.F.1.1. Open additional doors or windows.

F.1.2. Increase house exhaust ventilation by installing additional ceiling vents, such as Dial's UP-DUX™ Ceiling-to-Attic Exhaust Vent (Dial PNs 7607-7610).

F.1.3. Increase ventilation through attic.
F.2. Dirty pads.F.2.1. Clean or replace pads.
F.3. Belt tension too loose.See solution A.2.1.
F.4. Motor pulley diameter too small.F.4.1. For fixed diameter motor pulleys, see solution A.1.2.

F.4.2. For variable diameter motor pulleys, increase motor pulley diameter.
G. Excessive humidity level.G.1. Inadequate exhaust ventilation.See solution F.1.1., F.1.2. & F.1.3.
G.2. Outside air too humid.Turn cooler wall switch to vent position.
G.3. Bad thermostat.Replace thermostat.
H. Cooler air too warm / house air too warm.H.1. Dry pads.H.1.1 Check for defective pump switch. Replace switch if necessary.

H.1.2. Check water pump for proper operation. Replace if pump is not running, or if water flow from pump is severely inadequate.

H.1.3. Check for restriction(s) in pump elbow, pump hose, distributor head, distributor tubes, and drip trays. Remove restriction(s) or replace defective part(s).
H.2. Dirty pads.H.2.1. Clean or replace pads.
H.3. Excessive open area in pads.H.3.1. Repack or replace pads.
H.4. Clogged pump screen.H.4.1. Clean or replace screen.
H.5. Insufficient water level in reservoir.H.5.1. Adjust water shut-off level of float valve. Set water level to approximately 1/2 inch below top of overflow standpipe. At this level, the water pump should not suck in any air while it is running.
H.6. Cooler air being misdirected.H.6.1. Redirect cooler air in room by opening door(s) or window(s) where cooling is being effected.

H.6.2. See solution F.1.2 & F.1.3.
I. Water leaking from cooler / water running off roof.I.1. Reservoir water level too high.I.1.1. Partially drain reservoir and then see solution H.5.1.

I.1.2. Check seal of float valve. Water through valve should completely shut off when float is raised up. Replace if necessary.
I.2. Leak at fitting connection.I.2.1. Tighten fitting nut, or replace fitting if necessary.
I.3. Leak in tubing.I.3.1. Replace damaged tubing.
I.4. Clogged overflow standpipe.I.4.1. Clean or replace standpipe.
J. Water running into house.J.1. Excessive open area(s) in pad(s); typically on top.J.1.1. Reinstall or replace pads. Air flow can be strong enough to carry water drops into blower.
J.2. Distributor tubes do not discharge water into frame water troughs.J.2.1. Rework or replace distributor tubes and head to correct alignment.
J.3. Frame water troughs overflowing with water.J.3.1. Clean debris from slots of water trough.

J.3.2. Restrict water flow from pump using pump hose restrictor clamp.
K. Chattering sound.K.1. Float valve loose.K.1.1 Tighten float valve.
K.2. Float valve no longer seals.K.2.1. Replace float valve.
K.3. Copper water supply line vibrating.K.3.1. Re-support water line with tube straps.
L. Excessive noise.L.1. Loose motor.L.1.1. Tighten motor mounting bolts and nuts.

L.1.2. Tighten motor clamps.
L.2. Bent motor pulley.L.2.1. Replace motor pulley.
L.3. Bent blower pulley.L.3.1. Replace blower pulley.
L.4. Excessive motor shaft end-play.L.4.1. Replace motor.
L.5. Excessive blower shaft end-play.L.5.1. Adjust shaft collars. Replace collar(s) if necessary.
L.6. Excessive motor shaft wear.L.6.1. Replace motor.
L.7. Excessive blower shaft wear.L.7.1. Replace blower bearings and shaft.
L.8. Cooler not adequately secured to roof.L.8.1. Re-support cooler to roof.
M. Thumping sound.M.1. Damaged belt.M.1.1. Replace belt.
M.2. Mineral buildup on pulley(s).M.2.1. Clean pulley(s).
N. Squealing sound during start-up.N.1. Loose belt.N.1.1. See solution A.2.1.

N.1.2. Replace belt.
O. High pitched whine.O.1. Worn motor bearings.O.1.1. Replace motor.
O.2. Worn blower bearings.O.2.1. Replace blower bearings.
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