York B1HH036A06B Fan Question

[Phillip60]

I have (2) York B1HH packaged heat pumps. One of the units, the indoor fan runs continously, even pulling the call for wire (green) off the fan control board will not shut the fan off. I have gone as far as removing the defrost control board, the fan control board from my unit that is operating correctly and install this unit. The same thing happens, the fan continues to run. I thought that maybe the high limit switch has some sort of ohms reading the fan control board may be looking for so i removed the limit from the operating unit, put in this unit and still the fan runs non-stop. Does anyone have an idea of where to go from here before I put my 357 to the unit and put it out of its (my) mysery The full model # is B1HH036A06B. Serial # is NGJM085272

[Freon]

When did this problem start. Have you had any recent servicing done on the units. Have you had any recent electrical work done on the house.

Locate where the motor connects to the control board. There should be 2 connections, one for heating speed and one for cooling speed. Turn off the power and CAREFULLY label then disconnect the two motor speed wires from the control board. There should be one more connection from the motor to the board and that would be the neutral or common, usually a white wire You do not need to remove that. Now with the power back on, CAREFULLY measure the AC voltage between the Heat speed connection at the control board and the common connection at the control board. It may be 120 or 240 volts so be careful. Then do the same for the Cool speed connection at the control board.

From this data we will know what speed is keeping the motor always powered.

[Phillip60]

The problem started about a month ago. No service work performed except routine coil washing. No coil washing has been performed since august of 2012. No other electrical work performed. I do know that K1 relay will energize shortly after power is applied to unit. Makes no difference if stat wires are connected or not. I also failed to mention that emergency heat will not work. In looking at the schematic, it states K1 and K2 relays have some sort of logic applied to them which should control them. That is why I replace the high limit on the heat strips thinking that maybe there was an ohm reading the "logic" was looking for. But replacing the limit failed to cure the problem. To answer your question, the fan motor runs on medium speed.

[Freon]

The high limit usually only affects the burners, shutting them off while the blower continues to run, cooling the heat exchanger to an acceptable level whereupon the high limit closes reigniting the burners.

The 2 relays govern the Fan On, (G wire connection) and the heating logic. The fact that replacing both boards with similar ones had no affect on the blower is most strange. For some reason there is some signal causing the blower to be powered. With the power off, I would disconnect all thermostat wires from the air handler control board. If the blower still runs, then disconnect all wires coming from the heat pump control board, totally isolating the motor and air handler control board.. We need to isolate the source of the wrong logic signal, if there is one. Check all wire connections for anything suspicious.

The other possibility is there is something wrong with the motor itself. That is why I wanted to determine the voltages at the control board where the heating and cooling motor wires connect.