Pentair ULTRATEMP ETi 220 Installation And User Manual page 43

Problems or Symptoms
AGS LIMIT: Water temperature is above
140° F [60° C].
THERM FUSE OPEN: Thermal fuse circuit
is open.
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.
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.
Possible Cause
1. Insufficient water flow, excessive inlet
water temperature
2. Automatic gas shutoff switch
connections faulty
3. Automatic gas shutoff switch faulty
Excessive stack flue temperature without
LOW WATER FLOW, HI LIMIT SWITCH,
AGS LIMIT, or STACK FLUE HIGH Alarm
1. Air flow restriction in combustion system
2. Faulty air flow switch tubing
3. Faulty blower or blower wiring
4. Faulty ignition control module wiring
5. Faulty ignition control module
6. Faulty air flow switch or switch wiring
1. Inadequate gas supply
2. Faulty gas valve
3. Faulty gas valve wiring
4. Faulty flame sensor wiring
5. Flame sensor rod does not detect flame
6. Faulty spark igniter wiring
7. Faulty spark igniter, igniter wires or
ignition control module
8. Spark electrode rods do not ignite gas
Corrective Action
Verify proper flow to heater. Refer to HI LIMIT SWITCH Alarm
troubleshooting.
Verify connections at switch and in low voltage box. Clean or replace
terminals.
Check for continuity between switch terminals with water temperature
below 120° F [48.9° C]. Replace automatic gas shutoff switch if faulty.
Call technical support.
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.
Verify vinyl tubing between air flow switch and blower is not
disconnected, kinked, cracked, torn or punctured. Replace as necessary.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Inspect igniter wires for signs of tearing or cracking of outer casing and
boots. Replace igniter wires if degraded.
On call for heat, check for proper spark operation with ignition spark
tester. Replace igniter, wires or ignition control module if faulty.
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.
ULTRATEMP ETI™ Hybrid Heater Installation and User's Guide
39