Hubbell Electric Heater Company EMV - Manual (Page 12)

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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