Heater plate triac circuit faulty. E30 Power (on/off) button stuck on E31 Mute button stuck on E32 Mode button stuck on E40 Unit not functional tested at time of manufacture MR850 Technical Manual * Revision J * Issued November 2005 * Ref. 185041340 (185041713 internal) Error Description of Fault E41 Failed the functional test at time of manufacture E42 Was not stress tested during manufacture E43 Failed the stress test during manufacture E44 Not tested on functional tester 2 E45 Failed producti

• To upgrade both PCBs and the software use a PCB service upgrade kit. The part numbers to order are as follows: Model Part number Model Part number MR480 043040791 MR720 043040793 MR700 043040792 MR730 043040794 • For humidifiers with Rev F or later PCBs, you will only be required to purchase individual boards for repairs (as detailed in sect. 8.9). • If a revision H or later power PCB needs replacing, the replacement power PCB must also be revision H or later. Replacing revision F or earlier p

Ceramic 22 nF 50 V.............................................................................. 312040116 C22, C23 Cap. Mylar 10 nF 50 V................................................................................. 316040084 C21, C24 Cap. Ceramic 470 pF 50 V............................................................................ 312040118 D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12 Diode 1N4148.........................................................................................

Otherwise if a heater wire is not connected then the optoisolator will be turned on and off in synchronisation with the secondary cycle. The output of the optoisolator feeds U4 on the control board. This signal, with processor interpretation, provides the information to determine if the Heater Wire is connected or open circuit and also the integrity of fuse F2, the 4 A fuse supplying power to the Heater Wire. Q11 controls power to the heaterplate and is under control of optoisolator U12 and tran

25 8.6 Circuit Diagrams - Revision H and J PCB Power PCB ...................................................................................................... 26 8.7 Circuit Diagrams - Revision F PCB Control PCB..............................................................................................................27 8.8 Circuit Diagrams - Revision F PCB Power PCB ................................................................................................................ 28 8.9 Electri

Do not clean the mineral scale off the bottom of the water distribution tray at the end of the humidification season. The scale itself provides an excellent track for the water to follow. This is actually what we try to simulate with the synthetic coating in the bottom of the tray. If the coating is removed, it is not necessary to purchase a new distribution tray or upper housing. You can accomplish the same uniform performance by applying a small amount of liquid dishwashing detergent over the

Disconnect 9 MODELS 1. Inlet Grille 2. Distribution Tray 3. Scale Control Insert 4. Distribution Tray Cover 5. Water Panel 6. Drain Spud 7. Power Cord 3 4 5 6 7 8 1 2 8. Metal Housing 9. Evaporative Assembly 1. Disconnect electrical power and turn off water supply. 2. Remove screws of the inlet grille (1). The grille can now be removed from the metal housing (8). 3. Lift the complete plastic framed evaporative section out of the humidifier housing. 4. To remove the distribution tray (2) from eva

Slip drain line back onto the drain fitting. Make sure the drain line has a constant downward slope and is not flattened or blocked. 10. Turn on the water supply. Return integral bypass damper to appropriate position. 11. Check system operation: Manual Humidifier Control (Models 500M & 600M): With the HVAC blower operating, turn up Humidifier Control and check system operation. Digital Humidifier Control (Models 500 & 600): (Automatic or Manual mode) Check system operation and reset Change Water

• If none of the above is successful and you still need information, please feel free to write us. • Purchase only Genuine Aprilaire Water Panels to maintain performance. If your humidifier is equipped with an Automatic Humidifier Control with Water Panel change indicator, after replacing the Water Panel, turn the control knob to the “Test/Reset” position until the “Humidifier On” light blinks to reset its timer. (Blower must be operating and HVAC calling for heat.) Be sure to turn the control k