Enviro HL SERIES User Manual

ENVIRO-TEC
45
FORM ET115.24-NOM11 (118)
ELECTRIC HEATER TROUBLESHOOTING GUIDELINES
Problem Possible cause Corrective action
Electric Heat
will not operate
CAUTION:
UNIT MAY BE
EXTREMELY
HOT. TAKE
GREAT
CARE WHEN
TROUBLE-
SHOOTING.
Insucient airow Verify proper airow.
Loss of demand.
Verify thermostat or control is calling for heating. Verify
demand voltage is present at unit.
[24V units] Loss of demand. Verify 24V control signal at ‘W’ terminal during demand.
[24V units] Loss of 24V
Verify integrity of fuse on Fan Relay Board and replace if
need be. Refer to Fan Relay Board Troubleshooting Guide.
No airow.
Electric heat will not operate unless fan motor is enabled.
Verify fan speed is commanded.
Damaged primary limit wire
harness
Disconnect primary limit wire harness (the purple wire
harness coming out of the heater section.) Verify continuity
across wire harness. If no continuity, check if primary
limit is tripped. If primary limit is veried good, remove
power from unit, disconnect primary limit wire harness, and
measure continuity of wire harness. Replace if bad.
Primary limit switch tripped.
Verify no loss of demand to unit. Verify that voltage exists
on magnetic heater contactor during demand for heat. If
demand reaches unit but not contactor, primary limit is
tripped. The primary limit switch(es) will auto-reset once
the unit cools down. If unit is hot, wait for heater to cool
down. This may take up to an hour.
Secondary limit switch tripped.
The secondary limit may be manually reset. If unit is hot,
wait for the heater to cool down. This may take up to an
hour. Reset switch(es). Verify if heater will start.
Improper wiring connections Verify wiring to schematic.
Open or damaged heater elements
With power removed, disconnect heater wire harnesses.
(These are the harnesses with the black plugs.) Use a
volt-ohm meter to measure resistance across the electric
heat power harness coming out of the heater section. If
the meter measures an open or shorted circuit, inspect the
heating elements.
Damaged electric heat wire
harness
With power removed, disconnect heater wire harnesses. Use
a volt-ohm meter to verify continuity ofelectric heat power
harness wires in the control enclosure section.
Primary Limit switch fault
With power removed and heater cool, remove primary limit
switch. Verify continuity across switch. Replace switch if
open.
Secondary Limit switch fault
With power removed and heater cool, remove secondary
limit switch. Verify switch is reset. Verify continuity across
switch. Replace switch if open.
[Magnetic contactor] Electric
heat contactor fault
Verify heating demand voltage is at magnetic electric heat
contactor control coil terminals. If power is present but
contactor is not actuated, replace contactor. To verify
contactor: with power removed, unwire contactor and verify
continuity across contacts when manually operated. Cover
of contactor will need to be removed to access manual
operator. Replace contactor if faulty.

Enviro HL SERIES Specifications

General

Brand	Enviro
Model	HL SERIES
Category	Fan
Language	English