SSZ16 - Outdoor Unit Not Running

Goodman Heat Pump: SSZ16

Re: Outdoor Unit Not Running

• The thermostat is calling for either HEATING or COOLING.
• The Indoor fan is operating.
• Neither the Outdoor Fan or Compressor are operating.

The SSZ16 series can be a very confusing heat pump:

• The 2 thru 4 ton models have a 1-Stage compressor, while the 5 ton models have a 2-Stage scroll compressor.
• There are 3 different defrost boards, depending on size and series.
• The 2-stage models have an added safety (Discharge Thermostat)
• There are 5 different ways that Goodman wires the safeties.

CHECKOUT

1. Check High Voltage

• 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 (R) "Red" and (C) "Blue".
  • No Power = Blown Low Voltage Fuse or No Air Handler Power
• Check for 24VAC between (Y) "Pur" and (C) "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 "Pur" and "Blue".
  • No Power at Contactor + Power on "Y" (Pur) = Open Safety → Step 4. Check Safeties
  • Power at Contactor + Contactor Not Pulled-In = Bad Contactor

4. Check Safeties

• Unfortunately, there are at least (6) different ways that Goodman has wired the safeties depending on the size and the series of the unit.
  • Method 1: "Y" breaks thru the Hi Pressure Switch, then the Low Pressure Switch before hitting the compressor contactor.
  • Method 2: "Y" breaks thru the Hi Pressure Switch, then the Discharge Thermostat, then the Low Pressure Switch before hitting the compressor contactor.
  • Method 3: "Y" goes directly to the contactor and "C" breaks thru the Hi Pressure Switch, then the Discharge Thermostat, then the Low Pressure Switch before hitting the compressor contactor.
  • Method 4: "Y" breaks thru the Hi Pressure Switch to the defrost control Y terminal and the Low Pressure switch connects to the defrost board PS1 and PS2 terminals.
  • Method 5: "Y" goes directly to the Y terminal on the defrost board, "C" breaks thru the Discharge Thermostat, then thru the Hi Pressure Switch, and the Low Pressure Switch connects the the defrost board PS1 and PS2 terminals.