10
SECTION IV – TROUBLESHOOTING
Symptom Probable Cause Corrective Action / Remedy
No hot water in
tank
Circuit breaker tripped at
source.
Reset circuit breaker.
High limit switch tripped. Reset high limit switch.
Loose wires. Torque screws holding wires.
Heating element inoperable. Check heating element operation by
clamping an Amprobe around each
wire to the element. The ampere
reading should agree with the
nameplate ‘AMP’ figure.
Low line voltage. Have source electrical system
checked by an electrician.
Faulty thermostat. Move thermostat dial through full
range. A definite ‘click’ should be
heard. If not, replace thermostat.
Water temperature
in tank below
settings at all
times
Faulty thermostat. Check thermostat adjustment.
Monitor thermostat as described in
Section III, Quarterly Inspection.
Replace if necessary.
Heating element not
working on all phases
Check to see that heating element is
working on all phases, by checking
the resistance (ohms) value for each
element and comparing with the
chart included in Section VI.
Heater improperly sized Verify heater is properly sized for the
flow rate and temperature rise of your
system. Replace elements with proper
size as necessary.
Relief valve
discharges
continuously
Excessive temperature or
pressure in tank
Temperature and pressure relief
valves are made to operate if the
water temperature exceeds 210°F or
water pressure exceeds the pressure
rating of the safety relief valve. If
trouble is excessive temperature, then
thermostat is not shutting off at the
right setting and thermostat must be
replaced.
Tepid water
temperature too
hot
Blockage in cold water inlet
to mixing valve
Disconnect mixing valve and clean
out cold water inlet pipe.
Mixing valve out of
calibration
Re-calibrate mixing valve as
described in Section V, Service and
Replacement of Parts, Re-Calibrate
Mixing Valve.
Tepid water
temperature too
cold
Blockage in hot water inlet
to mixing valve
Disconnect mixing valve and clean
out hot water inlet pipe.
Mixing valve out of
calibration
Re-calibrate mixing valve as
described in Section V, Service and
Replacement of Parts, Re-Calibrate
Mixing Valve.
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