Rheem IKONIC RTGH-S11i Training And Service Manual page 56

IKONIC Tankless Water Heater Service Manual
ERROR CODE DIAGNOSTICS
2.2 ERROR CODE LIST
A018 ERROR CODE
Lime build-up inside the heat exchanger
To prevent permanent damage to the unit, the unit must
be drained and flushed. Flushing procedure may need
to be repeated for excessive lime and scale build up.
After flush procedure has been done. Clear current
alarm. Section 1.7.
Hot Water
Service Valve
Drain Hose
(hot water)
Utility Pump
5 - Gallon Bucket
56
NOTE: Flushing instructions utilize a submers-
ible utility pump.
(Provided with the Rheem/Ruud Tankless
Flush Kit - RTG20124)
Drain Hose
(cold water)
Cold Water
Service Valve