Installation Guide

TROUBLESHOOTING
Electric Tankless Water Heater • 21
Symptom Possible Cause Corrective Action
Unit “clicks” periodically when no hot
water is being used.
Cold water used causes reverse flow
through water heater.
Install check valve on outlet.
Unit has been in standby for an
extended period with no hot water
use.
NORMAL OPERATION. Unit will
activate as needed to maintain a
reference temperature to ensure
quick start-up on next use.
Hot water supply is warm, but it does
not get hot.
Temperature set point too low. Increase the temperature set point.
Flow is too high.* Reduce flow.
One of the main circuit breakers may
be tripped. (For units with more than
one branch circuit only.)
Check power panel. Reset breaker if
tripped.
Failed heating element or
temperature sensor.
Replace element or sensor
(thermistor).
Hot water supply is cold.
Flow is too high.* Reduce flow.
High temperature limit switch may be
tripped.
Verify if limit switch is tripped. Reset
if tripped.
The circuit breaker(s) may be tripped. Check power panel. Reset breaker if
tripped.
Failed heating element or
temperature sensor.
Replace element or sensor
(thermistor).
Control board failure. Contact Technical Support.
Hot water temperature fluctuates.
Flow is too high* Reduce flow.
One of the main circuit breakers may
be tripped. (For units with more than
one branch circuit only.)
Check power panel. Reset breaker if
tripped.
Failed heating element or
temperature sensor.
Replace element or sensor
(thermistor).
* If your water heater runs out of hot water too quickly, it may be too small for your needs. Consider replacing it with a
larger model or adding additional heater(s) to meet flow demand. Please refer to the product specification sheet for
proper flow rates based on incoming water temperature.
General Troubleshooting
The following chart provides an overview of basic troubleshooting.