CHeCkInG SySTeM oPeRaTIon & TRoUbleSHooTInG
The following troubleshooting guide is intended to help diagnose and resolve general operational problems with Model 800 Humidifier . If a
problem persists, call Aprilaire Tech Support toll-free at 1-800-334-6011 . Please be prepared to describe the exact nature of the problem .
For general operational problems, check to make sure humidifier is installed correctly .
CaUTIon
Contact with electrical circuits can cause property damage, personal injury or death. Service and Troubleshooting must be
performed by qualified electrician.
TeST MoDe
To check general function of humidifier and components, the following Test Mode procedure can be performed . Humidifier must be powered and
ADHC knob must be turned to OFF position . The humidifier should be plumbed to a water supply and the drain line should be connected . Test
Mode involves repeatedly pressing the On/Off button and listening for audible clicks as the various components are energized and de-energized .
The humidifier will remain in Test Mode for five minutes, then automatically return to the Off state . If the procedure is not completed in five
minutes, restart Test Mode . If the humidifier or components do not respond as indicated, investigate components being tested .
1 . Press the On/Off button and hold it for 10 seconds until all display lights turn on . On/Off, Fill, steam and Drain lights will be green . Service
light will be red .
2 . Press On/Off button again . All display lights will turn off .
3 . Press On/Off button again . Fill light will illuminate red and Steam light will illuminate yellow .
4 . Press On/Off button again . Red Fill light will turn off . Steam light will remain yellow .
5 . Press On/Off button again . Listen for audible click as Power Relay is energized . If click is not heard, remove brown wires from terminals J7
and J8 and measure voltage across terminals J7 and J8 . If 24 VAC is present, replace Power Relay . If 24 VAC is not present, replace control
circuit board .
6 . Press On/Off button again . Listen for audible click as power relay is de-energized . If click is not heard, remove brown wires from terminals
J7 and J8 and measure voltage across terminals J7 and J8 . If less than 1 VAC is present, replace power relay . If more than 1 VAC is present,
replace control circuit board .
7 . Press the On/Off button again . Listen for a click as the fill valve is energized . Water should flow, filling the canister . If the valve does not
energize . measure voltage across the J6 FILL terminals on the control circuit board . If 24 VAC is present, replace fill valve . If 24 VAC is not
present, replace control circuit board .
8 . Press On/Off button again . Listen for click as fill valve is de-energized . Water should stop flowing . If valve remains energized, check for
voltage across “J6 FILL” terminals on control circuit board . If less than 1 VAC is present, replace fill valve . If more than 1 VAC is present,
replace control circuit board .
9 . Press the On/Off button again . Listen for a click as the drain valve is energized . Water should flow down the drain . If the valve does not
energize, remove the drain valve wires from terminals J3 and J4 on the control circuit board and measure voltage across the terminals . If 24
VAC is present, replace drain valve . If 24 VAC is not present, replace control circuit board .
10 . Press On/Off button again . Listen for click as drain valve is de-energized . Water should stop flowing down the drain . If valve remains
energized, remove the drain valve wires from terminals J3 and J4 on the control circuit board and measure voltage across the terminals . If
less than 1 VAC is present, replace drain valve . If more than 1 VAC is present, replace control circuit board .
11 . Press the On/Off button again . Listen for a faint click as the FAN PACK terminals on the control circuit board are energized . If the terminals
do not energize, (24 VAC measured across terminals) replace the control circuit board .
12 . Press On/Off button again . Listen for click as FAN PACK terminals are de-energized . If the terminals fail to energize (more than 1 VAC
measured across terminals) replace control circuit board .
Exit Test Mode by disconnecting power to humidifier or allowing five minutes to elapse .
20
