Hubbell Electric Heater Company SLN - Manual (Page 14)

14
BACK-UP ELECTRCIAL HEATER SYSTEM (if supplied)
Symptom Probable Cause Corrective Action / Remedy
Circuit breaker tripped at source. Reset circuit breaker.
High limit switch tripped.
Reset high limit switch.
Loose wires. Tighten wires. Torque screws per torque
chart included in Section VI.
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.
No hot water
Faulty thermostat. Move thermostat dial through full range. A
definite ‘click’ should be heard. If not,
replace thermostat.
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 expected rating.
Water temperature
below settings at all
times
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.