Chapter 6—REFRIGERATION AND AIR CONDITIONINGTESTREMEDYTROUBLEPOSSIBLECAUSERelocate thermostat toa place more repre-sentative of averagespace temperature.Space temperaturehigher than thermostatsetting and thermostatcontacts are open.B a d l o c a t i o n o fthermostat.Carefully read tempera-ture at the sensingelement.Thermostat out of ad-Calibrate with goodClean, adjust, orjustment or sticking.thermometer.replace the thermostat.Cooling coil magneticvalve not opening.Solenoid Valve.Valve sticking.Replace solenoid coil.Clean valve or adjustpilots.Spacetemperaturethermostat lower thanthermostat setting andcontacts are closed.Bad location of ther-mostat (this will also ef-fect cooling).Test with reliable ther-Move thermostat to amometer at location.better location.Spacetemperaturelower than thermostatsetting and thermostatcontacts are open.Cooling coil magneticvalve stuck in openposition.Stuck valve.Disassemble and clean.Replace solenoid coil.Clean the valve.Heating coil magneticvalve stuck or badsolenoid.Test solenoid.Test valve.Thermostat or humidi-stat time constant toolow, causing widedeviation from setpoint.Sensing element fouledwith lint and dirt.Examine.Clean.Electric heater does notController contactsUse test lamp tocut out.stuck.determine.Replace contacts,springs or other parts asfound defective.Electric heater does notOverheat protectioncut in.not reset or defective.Place test lamp across.Repair or replace.Figure 6-13.—Trouble diagnosis chart.6-21
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