Troubleshooting - Hubbell Electric Heater Company HE Operating And Maintenance Manual

Symptom
No hot water
Water temperature
below settings at all
times
Relief valve discharges
continuously
SECTION IV –
Probable Cause
Circuit breaker tripped at source. Reset circuit breaker.
High limit switch tripped.
Loose wires.
Heating element inoperable.
Low line voltage.
Faulty thermostat.
Magnetic contactor does not
energize.
Faulty thermostat.
Heating element not working on
all phases
Heater improperly sized
Excessive temperature or
pressure in tank

TROUBLESHOOTING

Corrective Action / Remedy
Reset high limit switch.
Tighten wires. Torque screws per torque
chart included in Section VI.
Check heating element operation by
clamping an Amprobe around each wire
to the element. The ampere reading
should agree with the nameplate 'AMP'
figure.
Have source electrical system checked
by an electrician.
Move thermostat dial through full range.
A definite 'click' should be heard. If not,
replace thermostat.
Replace complete magnetic contactor.
Because of the design of this particular
contactor, it is more desirable to replace
complete control rather than rebuilding
coil, contacts and springs, etc.
Check thermostat adjustment. Monitor
thermostat as described in Section III,
Quarterly Inspection. Replace if
necessary.
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.
Verify heater is properly sized for the
flow rate and temperature rise of your
system. See formulas included in
Section VI. Replace elements with
proper size as necessary.
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.
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