Pentair MASTERTEMP 125 User Manual

P/N 475114 Rev. F 8/2020 MASTERTEMP 125 Pool and Spa Heater Installation and User’s Guide
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Section 3. Troubleshooting
Initial Troubleshooting
Only qualified, trained service technicians with appropriate test equipment should service the heater. Remember
that all parts of the system affect heater operation. Before starting this troubleshooting procedure, make sure
that the pump is running correctly, that there are no blockages in the system, that the valves are correctly set
and that the time clock is correctly set and is running.
CAUTION: Installing the BLACK 120 volt plug in the control box and then connecting the heater to a
240 volt line will destroy the transformer, control broad, and ignition control module, and will void the
warranty. If you install the RED 240 volt plug and then connect the heater to a 120 volt line, the heater
will not operate. See page 17.
READ THE FOLLOWING INFORMATION CAREFULLY
1. Check the line voltage to your heater. This heater will operate on either 120 Volts AC or 240 Volts AC.
2. Remove the covers and check the 12-pin plug in the back of the control box. The plug must match the
voltage in the heater circuit.
3. If the 12-pin plug is not plugged into the back of the control box, select the correct plug from the bag in
the control box and plug it in. The BLACK plug is for 120 volts, the RED plug is for 240 volts.
Error and Fault Codes
Table 8. Heater Error and Fault Codes
Fault Condi�on
Error Code
Displayed
Note
Troubleshoo�ng
Water pressure switch
open
ERR PS
If water ow is established the
the error is cleared and normal
operaon is resumed.
No water ow thru
heater
Hi temperature limit
switch open
ERR HLS
When the temperature falls
below 135°F the error is cleared
and normal operaon is
resumed.
Water temperature aer
the 1
st
pass through the
heater exchanger is more
than 135°F.
Air ow switch open
ERR AFS
If adequate air ow through the
blower is established within 60
seconds the heater will resume
normal operaon. If the error is
not corrected within 60 seconds
the heater will need to turned
o by pressing the HEATER OFF
buon.
The blower is not on or
air thru it is being
restricted
Ignion Control Module
ERR IGN
To clear the error the HEATER
OFF buon must be pressed.
The Ignion Control
Module was not able to
ignite the heater.
Automac gas shuo
ERR AGS
The front panel buons will be
disabled. To reset the heater,
cycle power.
Water temperature aer
the 2
nd
pass thru the heat
exchanger is more than
140°F
Excessive stack ue
temperature
ERR SFS
The front panel buons will be
disabled. To reset the heater,
cycle power.
The temperature of the
stack ue is more than
480°F
Open stack ue sensor
E05
Shorted stack 
sensor
E06
The front panel buons will be
disabled. To reset the heater,
cycle power.
Follow diagram on page
37
Open water
temperature sensor
E01
To clear the error the HEATER
OFF buon must be pressed.
Follow diagram on page
35
Shorted water
temperature sensor
126
Follow diagram on page
35
Follow diagram on page
37
Section 3. Troubleshooting

Pentair MASTERTEMP 125 Specifications

General

BTU Output	125, 000 BTU/hr
Fuel Type	Natural Gas or Propane
Ignition System	Electronic
Minimum Flow Rate	20 GPM
Maximum Working Pressure	50 PSI
Efficiency	82%
Water Connections	1.5 inch
Certifications	ANSI Z21.56
Voltage	120V