York Gas Furnace: YM9M / PM9 / YP96 / PC9 Re: Sequence of Operation (Heating) There are two styles of York Modulating Gas Furnaces, a Variable Speed Blower model and a standard PSC motor. Both styles have the same basic sequence of operation in the heating mode Pressure Switch Proving ...

York Gas Furnaces: YM9M Re: Diagnostic/Fault Codes These York gas furnaces have a control board inside the furnace blower compartment that will flash a diagnostic code that shows the operating status of the furnace. Diagnostic Codes: 1 Green Normal Operation - no call for heat ...

York Gas Furnace: YM9M Re: Test Mode During normal operation, the furnace input rate can vary between 35% and 100% of full nameplate input, making it difficult to check for proper operation. To help with the furnace startup and testing process, the control has a TEST MODE available that allows...

York Gas Furnace Re: Water Leak / Clear Condensate Pan Covers All of the 33" gas furnaces originally came with a clear, plastic condensate pan cover. Over time, the clear plastic pan has a tendency to crack and cause condensate leakage inside the furnace cabinet. Any clear condensate pans...

Gas Furnace Re: Blown Low Voltage Fuse The low voltage fuse provides protection for the control board and other low voltage components in the case of high amperage caused by a low voltage short or excess component load. ► The fuse must be sized per the "VA" of the transformer. Amps = VA...

York Gas Furnaces Re: Clear Collector Box Cover The original models of this furnace came from the factory with a clear collector box cover. While this provided a good visual confirmation of the amount of water in the collector box, the clear plastic tends to crack and cause water leaks. ...

York 90% Gas Furnace: YM9M Re: Flashing Code 3 Code 3 = Furnace Pressure Switch failed to close on a call for heat. ►The code description on the blower door may say, "Vent or Termination Problem" which is a possible cause, but not the most likely. This gas furnace has two pressure...

York 90% Gas Furnace: YM9M Re: No Heat - Code 7 Code 7 = Failure to Sense Flame The control will make three attempts to establish flame before locking-out on Code 7. Qty Possible Causes: 3 Bad Gas Valve 1 Dirty Flame Sensor 1 Bad Glow Plug Clogged...

York Gas Furnace: TM9M / YM9M / YP9C Re: Flashing Code 8 Code 8 = Loss of flame signal ► Flame was established and later lost, 5 times during a heating cycle. Qty Possible Causes: 2 Dirty Flame Sensor Bad Glow Plug Clogged Burners No or Low Gas...

York Gas Furnaces: TM9M/YM9M Re: Add-On Heat Pump Stuck In Cool When this furnace is used in an add-on heat pump application, the heat pump only runs in the cooling mode ("O" stays energized). ► There is a jumper on the furnace control board to select Heat Pump: "Yes" or "No". When...