Swimming Pool Blog


Pentair Pool Heater Troubleshooting Guide

Pentair Pool Heater Troubleshooting Guide
by Mark Garcia January 08, 2019

Pentair pool heaters come from the legacy of the Purex-Triton Minimax heater, when Pentair purchased the Purex company. In 2004, Pentair acquired the Sta-Rite company and it's Max-E-Therm heater technology. The Pentair MasterTemp pool heater adopted the sealed combustion chamber with controlled exhaust design.

The MiniMax pool heater design is no longer being made by Pentair, but parts will continue to be manufactured for years to come, so fear not if you have a Pentair Minimax, which shares a common gas pool heater design with other brands like Hayward and Raypak.

Today's post is specifically about the not-so-new style of pool heater design, used in the Pentair MasterTemp and Sta-Rite Max-E-Therm heaters.

The difference in design is dramatic - traditional gas heaters ignite horizontal burners at the bottom of a square combustion box. The air space above the burners heats up, which heats the copper finned tubes laying on the top of the combustion box. The water circulating through the copper heat exchanger tubes absorbs the heat, and exits the heater a few degrees warmer than when it entered.

Sta-Rite Max-e-Therm heatersBy contrast, the Sta-Rite Max-e-Therm pool heater design, now adopted by Pentair, has stacks of circular heat exchanger tubes, surrounding a combustion cylinder. Gas and air are mixed and ignite in the cylinder, which warms the tubes that are wrapped around the central burner chamber. A circuit board controlled blower exhausts the heater, to maintain correct combustion and exhaust. 

Troubleshooting the stacked exchanger type of heater is not much different than other electronic or digital pool heaters. The controls and circuit boards for the Max-E-Therm and the MasterTemp are fairly identical. Even the new MasterTemp aboveground pool heater has the same design, and the same troubleshooting procedure. The error codes below can get you started with understanding what your heater is trying to tell you.  

Good Luck!

Our Pentair Matertemp Troubleshooting Guide starts with the error codes shared by both models, and follows into a 6 page flowchart to step by step troubleshoot a Pentair or Sta-Rite pool heater, and get it firing again fast!

PENTAIR MASTERTEMP ERROR CODES

PENTAIR MASTERTEMP ERROR CODES
CODE MEANING
AGS AUTOMATIC GAS SHUTOFF
HLS HIGH LIMIT SWITCH
PS PRESSURE SWITCH
AFS AIR FLOW SWITCH
SFS STACK FLUE SENSOR
E01 TEMPERATURE SENSOR
E02 HIGH LIMIT SENSOR 
E03 THERMAL FUSE ERROR
E04 FAN SENSOR
E05 STACK FLUE SENSOR

 

PENTAIR MASTERTEMP ELECTRICAL TROUBLESHOOTING

 PENTAIR MASTERTEMP TROUBLESHOOTING GUIDE PAGE 1-5

 

 PENTAIR MASTERTEMP TROUBLESHOOTING GUIDE PAGE 6

 

PENTAIR HEATER BURNER TROUBLESHOOTING: 

old style heater burner trayThe burners on this type of MasterTemp/Max-e-Therm heater are quite unique from previous generation pool heaters. Older style heaters use a low horizontal manifold supplying dozens of individual burners across the bottom of the burner tray, shown at left.

new style pentair burner, the flameholder

The Burner System of the MasterTemp/Max-e-Therm heaters is one single burner, called the Flame Holder, shown right. The burner is located in the center of the combustion chamber, wrapped by the circular copper heat exchanger tubes. The single glowing burner is aided by the blower fan, which regulates the correct amount of exhaust and is plays a large role in correct combustion. 

 

PENTAIR HEAT EXCHANGER TROUBLESHOOTING:

radical pentair starite heater design The biggest fear about the heat exchanger is that corrosion can occur to the relatively soft copper finned tubes, causing them to develop pinhole leaks. Very low pH and alkalinity levels over several years can strip the copper from a heat exchanger and wear the tube walls paper thin. Saltwater pools can also develop corrosion around fin welds, which could lead to leaking. Cupro Nickel heat exchangers can be used for much greater resistance to the effects of salt water corrosion. 

Leaking heat exchangers are often confused with sweating or condensating heat exchangers. A second major problem with heat exchangers is scaling water conditions and poor combustion could lead to build-up of lime scale inside the copper tubes, which renders the heat exchanger useless and requires a replacement. 

pentair heat exchanger troubleshooting

 

pentair and starite line art schematic parts diagramPentair MasterTemp pool heater parts are arranged into 3 'parts buckets' - Burner System parts, Electrical System parts, and Water System parts. The same is true for the StaRite Maxetherm heaters. 

Just another way that Sta-Rite built a radically different heater. A completely redesigned pool heater that allows the Pentair MasterTemp and Sta-Rite Max-e-Therm heaters to be over 50% smaller in size and footprint. 

I sincerely hope that this post has helped you solve your pool heater problem!  

 

Thanks for Reading!

Mark Garcia