Rheem · ProTerra 120V plug-in

Rheem ProTerra 120V plug-in error code A108

Condensate Blocked: Unclog Line

What it means

Heating source defaults to elements due to condensate drain blockage

Source: Residential 120V plugin Heat Pump Water Heater (Dedicated Circuit) Use & Care Manual, AP21914 Rev 02, page 30

Also listed in: Residential 120V Plugin With HydroBoost Heat Pump Water Heater (Shared Circuit) Use & Care Manual, AP22654 Rev 01, page 30

What Rheem says to do

These steps involve electrical testing or parts replacement. Rheem's manuals tell owners to leave that work to a qualified service technician.

1. Remove top cover from tank 2. Visually inspect to ensure condensate line is clear and there is not excessive condensate in condensate pan 3. If water is present, locate blockage and unlock [sic]. 4. Ask customer to where the condensate is being routed. 5. If pan is dry and no blockage is present, replace condensate sensor.

Last checked 2026-10-03.

Safety first

CAUTION: For your safety DO NOT attempt repair of electrical wiring, thermostats, or other safety devices. Refer repairs to qualified service personnel. (p.28)
WARNING: If the water heater has been subjected to fire, flood or physical damage, disconnect all power to water heater, and DO NOT operate the water heater again until it has been checked by a qualified service technician. (p.19)

From the manufacturer's manual for this series.

The same code on other models

Codes mean different things on different heaters. Match the series to the model number on your rating label.