ASZ/SSZ - High Electric Bill - Heating

Goodman Heat Pump: ASZ / SSZ14

Re: High Electric Bill - Heating

• The customers reports that the unit is heating but their electric bill is higher than normal.
• May also report that the unit runs too much or blows cool air.

CHECKOUT

1. Check Outdoor Unit

• Unit Status
• Inspect the outdoor unit and make the outdoor coil is not frozen-over.
  • Outdoor unit operating normally → Step 5. Check Refrigerant Pressures
• Power
• Open the outdoor unit control cabinet.
• Check for 200 - 240VAC on the inlet side of the compressor contactor.
  • No or Low Voltage ⇒ Check Power at Disconnect & Breaker Panel
• Check to see if the compressor contactor is pulled-in.
  • Not Pulled-In → Step 3. Check Low Voltage
  • Pulled-In ⇒ Continue
• Check for 200 - 240VAC on the leaving side of the compressor contactor.
  • Contactor Pulled-In + No or Low Voltage = Bad Contactor
  • Power Present + No Operation → Step 2. Check Capacitor

2. Check Capacitor

• Break power to the outdoor unit by pulling the service disconnect or turning off the breaker.
• Remove wires from "C" and "HERM" of the capacitor.
• Move Meter leads to COM and MFD.
• Set Meter to 200 MFD.
• Place one lead on capacitor "C" and the other on capacitor terminal "HERM" 
• Confirm MFD reading with capacitor rating.
  • Less than 80% of rating = Bad Capacitor
• SWITCH METER LEADS BACK TO COM AND V BEFORE PROCEEDING!

3. Check Low Voltage

• At the outdoor unit low voltage connections, check for 24VAC between "Red" and "Blue".
• Check for 24VAC between "BL/PK" and "Blue".
  • No Power = No call from the thermostat ⇒ Recheck thermostat and look for a condensate overflow switch at the air handler.
• Check for 24VAC at the compressor contactor coil "YL/PK" and "Blue".
  • No Power at Contactor + Power on "Y" (BL/PK) = Open Safety → Step 4. Check Safeties
  • Power at Contactor + Contactor Not Pulled-In = Bad Contactor

4. Check Safeties

• At the wire-nut splice, check for 24VAC between "BL/PK ⇔ YL/PK" and "Blue".
  • No Power = Open Hi Pressure Switch
  • Power Present ⇒ Continue
• At the compressor contactor, check for 24VAC between "YL/PK" and "Blue".
  • No Power = Open Low Pressure Switch
  • Power Present + Contactor Not Pulled-In = Bad Contactor

5. Check Refrigerant Pressures

• Hook-up refrigerant gauges to the pressure ports on the unit.
  • Blue --> "True Suction" Low Pressure
  • Red --> High Pressure (either refrigerant line)
• Monitor pressures as the system operates.

• If a Liquid-Line Sight Glass is installed, observe for bubbles in the sight glass (after the system has been operating for at least 5 min.)
• Suction Pressure Issues
  • Low Suction + Low Discharge + Clear Sight Glass + Expansion Valve Frosting = Bad O/D Expansion Valve 
  • Low Suction + Low Discharge + Bubbles in Sight Glass + Expansion Valve Frosting = Low Refrigerant Charge
    • 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 O/D Expansion Valve
• High Pressure Issues
  • Monitor pressures and temperature as the system operates.
    • If the discharge pressure exceeds Normal Range or kicks-off on Hi Pressure safety in the first 5 minutes = Refrigerant Overcharge or No Indoor Blower
  • Clear Sight Glass + High Discharge + High Suction = Overcharged
  • Clear Sight Glass + High Discharge + Low Suction = Bad Expansion Valve
  • Bubbles in Sight Glass + High Discharge = Low Indoor Heat Transfer → Step 6. Check Air Temperature Rise

6. Check Air Temperature Rise

• Remove "W1" and "W2" form the air handler 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 THE AIR HANDLER!