ULTRATEMP ETI™ Hybrid Heater Installation and User’s Guide
39
Problems or Symptoms
Possible Cause
Corrective Action
AGS LIMIT:
Water temperature is above
140° F [60° C].
1. Insufficient water flow, excessive inlet
water temperature
Verify proper flow to heater. Refer to
HI LIMIT SWITCH
Alarm
troubleshooting.
2. Automatic gas shutoff switch
connections faulty
Verify connections at switch and in low voltage box. Clean or replace
terminals.
3. Automatic gas shutoff switch faulty
Check for continuity between switch terminals with water temperature
below 120° F [48.9° C]. Replace automatic gas shutoff switch if faulty.
THERM FUSE OPEN
: Thermal fuse circuit
is open.
Excessive stack flue temperature without
LOW WATER FLOW, HI LIMIT SWITCH,
AGS LIMIT
, or
STACK FLUE HIGH
Alarm
Call technical support.
AIR FLOW FAULT
:
Air flow switch is open
CAUTION: High Voltage Checks. Observe
extreme caution or call dealer or factory for
advice before attempting to Troubleshoot
Electrical Box.
1. Air flow restriction in combustion system
Clear obstruction from blower inlet or exhaust stack / vent.
Dust, soot or pollen buildup in heat exchanger. Remove burner and
clean coils.
Degraded insulation inside combustion chamber obstructing coils.
Replace insulation and clean coils.
2. Faulty air flow switch tubing
Verify vinyl tubing between air flow switch and blower is not
disconnected, kinked, cracked, torn or punctured. Replace as necessary.
3. Faulty blower or blower wiring
Disconnect blower at connector. On ignition try, verify line voltage at pins
1 and 3 of harness connector. If voltage checks ok, replace blower. If not
present refer to Faulty Ignition Control Module (wiring) troubleshooting
below.
4. Faulty ignition control module wiring
Verify 24 VAC at ignition control module terminal 24 VAC. Verify line
voltage at ignition control module terminal L1 and compressor contactor
T2. Replace harness if faulty. If not, refer to Faulty Ignition Control
Module troubleshooting below.
5. Faulty ignition control module
On call for heat, If blower does not run. With mains power off, disconnect
blower at connector and check continuity between blower harness
connector pin 1 and ignition control module terminal F2.
On call for heat, if blower starts but shuts off within 30 seconds refer to
Faulty Air Flow Switch or Switch Wiring troubleshooting below.
6. Faulty air flow switch or switch wiring
With mains power off verify connection at switch and at TH and IND
terminals on ignition control module. Check connection at TB-GI-4.
Clean or replace terminals. Replace air flow switch if faulty.
ICM FAULT:
Ignition control module does not
detect flame
CAUTION: High Voltage Checks. Observe
extreme caution or call dealer or factory for
advice before attempting to Troubleshoot
Electrical Box.
1. Inadequate gas supply
On call for heat heater does not fire, or fires but does not stay running.
Verify incoming gas supply line size and pressure. Verify gas supply line
is properly purged of air. Call technical support.
2. Faulty gas valve
On call for heat, verify 24 VAC at gas valve terminal. Verify gas valve is
switched ON. Call technical support to replace valve with identical part
if faulty.
3. Faulty gas valve wiring
Check continuity between gas valve ground and TB-O-1 terminals. On
call for heat, verify 24 VAC at gas valve terminal. Clean or replace wiring
terminals at valve if faulty. Repair or replace wiring harness if faulty.
4. Faulty flame sensor wiring
On call for heat heater fires but does not stay running. With mains power
off, check continuity between ignition control module terminal S1 and
flame sensor rod. Clean or replace terminal. Repair or replace wire if
faulty.
5. Flame sensor rod does not detect flame
Verify distance between the flame sensor rod to burner. Refer to
Figure
24
, page 33. Inspect rod for excessive solids buildup on surface, clean
or replace if faulty.
6. Faulty spark igniter wiring
Inspect igniter wires for signs of tearing or cracking of outer casing and
boots. Replace igniter wires if degraded.
7. Faulty spark igniter, igniter wires or
ignition control module
On call for heat, check for proper spark operation with ignition spark
tester. Replace igniter, wires or ignition control module if faulty.
8. Spark electrode rods do not ignite gas
Verify the distance between the spark electrode rods, and spark
electrode and the burners. Refer to
Figure 24
, page 33. Inspect
electrode rods for excessive solids buildup on surfaces, clean or replace
if faulty.
ENGLISH
