York Package Heat Pump: Heating

Re: High Electric Bill

When the customers reports an electric bill that is much higher than normally, that typically means that the auxiliary heaters are operating more than normal.

► The blower and auxiliary heaters are typically working normally or the customer would also be experiencing no heat.

CHECKOUT:

1. Check Power

• Disconnect power to O/D unit by pulling disconnect or turning off breaker.
  • Open the blower door and lower the electrical compartment cover. 
  • Use a multi-meter to check resistance across each fuse.
  • Inspect for burnt wiring or burnt contactor contacts.
• Re-apply power to the unit and set the thermostat to call for heat.
• Check for 24VAC between "R" and "C" on the ECM control board.
  • No Power = No High Voltage Power, Blown Low Voltage Fuse or Bad Transformer
• Check for 24VAC between "Y1" and "C" on the ECM control board.
  • No Power = No Call from Thermostat ⇒ Check Thermostat
  • Power ⇒ Compressor and Condenser Fan should start with 5 minutes.

2. Check Compressor Operation

• Compressor and Condenser Fan start and run normally → Step 3. Check Refrigerant Pressures
• Compressor Does Not Try to Start = Control in Lockout or Bad Control Board
  • Check for 24VAC between "LP" and "C", then "HP" and "C" on the ECM board.
    • Power on one but not the other = Open Hi or Lo Pressure Switch
    • Power on both = Possible Lockout. Cycle power to the unit to reset any lockouts and then Re-check.
      • Check for 24VAC power across both sides of the compressor contactor coil (allow time for "Wait" timer to expire).
        • Power but contactor doesn't pull-in = Bad contactor
        • No Power ⇒ Suspect Bad ECM Control Board
• Compressor Hums but Doesn't Run = Bad Capacitor, Locked-up Compressor, or Burnt Wiring
• Condenser Fan Starts but No Compressor ⇒ Check Compressor Contactor

3. Check Refrigerant Pressures

• Hook-up refrigerant gauges to the pressure ports sticking through the cabinet.
  • Red --> High Pressure
  • Blue --> Low Pressure
• Monitor pressure as the system operates.

• Low Pressure Issues
  • Low Suction + Low Discharge + Expansion Valve Frosting = Low Refrigerant Charge or Bad Expansion Valve
    • Try adding refrigerant through the Low Pressure gauge.
      • Suction and Discharge Pressures should gradually increase as refrigerant is added.
      • If the Discharge Pressure increases but the Suction stays low or drops = Bad Expansion Valve
• High Pressure Issues
  • Place an insulated temperature probe on the liquid line between the evaporator coil & O/D expansion valve.
  • Allow the unit to run for at least 10 minutes.
  • Monitor pressures and temperature as the system operates.
    • If pressure exceeds Normal Range or kicks-off on Hi Pressure safety in the first 5 minutes = Refrigerant Overcharge or No Indoor Blower
  • Check Sub-Cooling
    • Record "Saturation Temperature" from the discharge pressure gauge.
    • Subtract the Actual liquid line temperature reading.
      • Saturation Temp - Liquid Line Temp = Sub-Cooling
        • Sub-Cooling > 13 deg. + High Discharge + High Suction = Overcharged
        • Sub-Cooling > 13 deg. + High Discharge + Low Suction = Bad Expansion Valve
        • Sub-Cooling < 2 deg. + High Discharge = Low Indoor Heat Transfer → Step 5. Check Air Temperature Rise

4. Check Compressor Discharge Temperature

• Use a multi-meter to check the temperature of the compressor discharge line.
• Normal Temperature = 120 - 150 deg.
  • Low Discharge Temp = Inefficient Operation

5. Check Air Temperature Rise

• With the auxiliary heaters disconnected (remove "W1" and "W2" form the ECM terminal block):
  • Check the Return Air Temperature near the unit or in the filter compartment.
  • Check the Supply Air Temperature.
  • Normal Temperature Rise = 15-20 deg.
    • Abnormally Low Return Air Temperature ⇒ Check Return Ductwork for Cold Air Infiltration
    • Low Temperature Rise = Inefficient Operation
    • High Temperature Rise = Low Airflow
  • RE-HOOK "W1" AND "W2" WIRES ON ECM BOARD!

6. Check Thermostat Aux Ht Settings (New VisionPro 8000)

• Check the Aux Heat Control Setting
  • Under Installer Setup, go to Setup #309
    • Change from "comfort" to "2.0" or "3.0"
  • Press Done to save changes.
    • This change doesn't allow Aux Ht operation unless the indoor temperature drops [#309] degrees below setpoint.