AtL Ambient temperature limited

What the control is telling you

Operation is restricted because the outdoor temperature is outside the operating range.

Applies to: Bosch IDS Light BOVA15-24/36/60 and IDS Premium Connected BOVA36-20/60-20 R-454B heat pump outdoor units

Likely causes

• Ambient outside 15-125 F in cooling or -4 to 86 F in heating
• Thermostat O/B setting wrong
• T4 sensor wiring or reading wrong

Test and repair steps

1. Wait for the temperature to come back into range.
2. Check the thermostat O/B setting for heating.
3. Check the T4 resistance against the sensor table; reseat or replace T4 and restart.
4. Check wiring against the diagram.

Models that show this code

5 models in Bosch IDS Light, Bosch IDS Premium Connected

Other codes on the same units

• P4 High compressor discharge temperature
• P5 Condenser coil temperature protection (cooling)
• P11 High pressure protection (transducer)
• P21 Low pressure protection
• P31 Input over-current protection
• P32 Compressor over-current protection
• EA Control and drive program mismatch
• PH Low discharge superheat protection