38 11112014GW
Code LC, LC0 – LC9 Troubleshooting Procedure
Scale build-up in Heat Exchanger
WARNING: Turn off the electrical and supply to the water heater before proceeding.
1. Flush heat exchanger per recommended flushing procedure found in unit’s owner’s manual.
2. NOTE; the LC, LC0 – LC9 codes are the only codes that will allow a unit to continue to operate.
The display will alternate between the LC codes and the temperature setting. The controller will
continue to beep.
On older product you can reset the LC code by turning off the power and then turning it back
on.
On newer product there is a shutdown feature built into the product to prevent damage caused
by the unit scaling up. See reset function for these units below:
• LC, 00, or LC0 – LC9 indicates that there is a scale build-up in the heat
exchanger and that it needs to be flushed to prevent damage. Refer
to the flushing instructions in the owner’s manual. Hard water must
be treated to prevent scale build-up or damage to the heat
exchanger. The above codes will lock the unit out requiring a reset
function, see below how to reset.
• To operate the water heater temporarily until the heat exchanger
can be flushed, push the on/off button on temperature controller 5
times. ( unit will operate for 70hrs and lock out with another LC code)
Example: LC2 indicates unit has been reset for 3 - 70hr periods
without flush and hard reset.
After flushing unit, the procedure to reset LC codes:
• Push the two switches (A & B) on PCB at the same time for 5 seconds.
• Unit will return to normal operation and LC# count returns to 0.
After temporarily reset, controller will cycle between set temperature
and LC#
This hard reset procedure is not in owners/installation manual or tech sheet.