Heat Pump: Bosch M15G
Re: P2 Fault / H5 Fault (Heating Mode)
P2 Fault = Low Pressure Protection (Heating or Cooling)
H5 Fault = P2 Fault occurred 5 times in 100 minutes or runtime (Requires Power Reset)
| Qty |
Possible Causes: |
|
Low Refrigerant Charge |
|
Bad O/D Fan Motor |
|
Not Defrosting |
|
Service Valves Closed |
|
Bad Pressure Transducer |
CHECKOUT:
1. Check Refrigerant Pressures
- Pull the service disconnect.
- Make sure the outdoor coil is not frozen-over.
- Frozen coil = Not Defrosting
- Hook-up refrigerant gauges to the pressure ports on the unit.
- Blue ⇒ True Suction (Not Suction Line)
- Red ⇒ Liquid Line Pressure Port
- Low Standing Pressure (both sides) = Loss of Charge
- Normal Pressures ⇒ Continue
- Start the unit.
- Re-Insert the service disconnect.
- Allow the unit to run for 5-10 minutes.
- Monitor pressures as the system operates.
- Normal R410a Suction Pressure = 100 - 150 psig
- Check Parameter No. 9 to confirm that the Suction Pressure Transducer is reading correctly.