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Pool-heater brand guide

Pentair and Sta-Rite gas pool heaters

Smell gas or hear a CO alarm? Leave first.

If you smell gas, a carbon monoxide (CO) alarm sounds, or anyone may have symptoms of CO poisoning, leave first and call 911 from a safe place. Do not use switches, phones, or anything that could make a spark nearby. Then call your gas utility or propane company.

See all safety steps

Look up a message by model

Suncoast repairs and installs Pentair and Sta-Rite gas pool heaters that run on natural gas or propane. We work at homes in Sarasota and Manatee Counties. Call with the model on the label. Colin confirms the exact model and your address before he books the work. Suncoast is an independent service company. We are not a Pentair authorized dealer, warranty center, or manufacturer-certified service provider.
Call Colin941-961-9337

Call Colin at 941-961-9337. There is no online form on this page. Keep the cabinet closed and use only the visible details described below.

From model to message to next step

Follow these steps in order. Use the links to jump to the part of this page that helps.

  1. Check for danger firstGas smell, smoke, fire or a CO alarm? Leave and call from a safe place. Skip the rest.Safety steps
  2. Find the modelRead it from the label on the outside of the heater. Do not open a panel.Model list
  3. Copy the messageWrite every letter and space. Note if it is steady or flashing, and if it came from the heater, a control system or an app.
  4. Match bothFind your model, then your message. No match? Do not borrow a meaning from another model.Message lookup
  5. Take the next safe stepNote only what you can see from where you stand. Then call Colin with the model and the message. A technician finds the cause.

Pentair repair: what happens

Tell Colin what the heater is doing. It may not light, it may shut off, or it may run without warming the water. If the display shows a message, read it to him word for word, and say whether it is steady or flashing.

A code helps him prepare. It does not tell anyone which part failed. Pentair's own manuals walk through several checks before naming a cause. Colin checks the heater on site, along with the water flow, the controls and the gas supply around it. He explains what he found and gives you a price before any repair. Pool heater repair

Pentair replacement or new install: what gets reviewed

A new heater has to fit the gas supply, the equipment pad, the plumbing and the controls already there. The same brand name does not settle that. Colin reviews the old heater and the site before he quotes. Any gas line or regulator change is quoted as its own part of the job. Installation and replacement

Bought a Pentair heater online?

Pentair's warranty page (checked October 14, 2026) says this:

  • In-ground products bought from a store, pool builder or pool service company get at least one year of parts and labor coverage when they are professionally installed.
  • Products bought online, even from Pentair's authorized online sellers, get one year of parts-only coverage.
  • A product that needs professional installation but did not get it gets one year of parts only.

The same page has a table by model. It lists ETi heaters and MasterTemp and Max-E-Therm heaters on separate rows, so check the row for your model. Pentair also asks owners to register a new product to start warranty coverage.

Pentair decides what its warranty covers, not Suncoast. If you already bought a heater, tell Colin before any installation is agreed.

Which Pentair or Sta-Rite heater do you have?

Go by the outside label, not by how the cabinet looks.

  • MasterTemp and MasterTemp 125. Pentair lists both on its gas pool heater page.
  • Sta-Rite Max-E-Therm. Sold under the Pentair name. The label may say Sta-Rite.
  • ETi 400 and ETi 250. The gas heater page lists the ETi 400. The ETi 250 has its own Pentair product page. Copy the exact number from the label.
  • MiniMax. An older Pentair line. You may see MiniMax, MiniMax NT or MiniMax NT Low NOx. Copy the words exactly as printed.

UltraTemp ETi is different. It combines a heat pump and a gas heater in one unit. Suncoast does not work on heat pumps, so this unit is not part of our Pentair service. If your label says UltraTemp ETi, say so at the start of the call. Colin will tell you whether he takes on any part of your request.

What does a Pentair or Sta-Rite heater message mean?

Pentair and Sta-Rite gas pool heaters show short messages on the control screen. Some, such as ERR PS, mean a safety switch is open and the heater will not heat. Others are status notes, such as RS485 Control. A message tells you what the heater sensed. It does not prove which part failed. The message lookup below explains each message by model, with the manual page.

For nine fault messages, Pentair says not to run the heater. ERR HLS and ERR IGN are two of them. If one of the nine shows, use the guide's steps to turn off the gas. Then have a qualified technician check the heater (p. 45).

Pentair also says that if you hear water boiling inside the heater, there may not be enough water flow. It says to make sure the filter is not plugged. If the water stays too hot while the heater keeps running, turn the heater off and call a technician (p. 58). Check the filter only with the owner steps in its own manual, or ask a technician to do it.

Message lookup by model

Find your model, then your message. Each card gives the exact words, what they mean, what the manual checks, what you can safely note, and the page it comes from. A message is a clue. It does not prove which part failed.

MasterTemp 175 to 400 and Sta-Rite Max-E-Therm

Page numbers are from the MasterTemp guide. The Max-E-Therm guide has the same message table on page 44 and the same warning on page 41.

ERR PS

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The water pressure switch is open. That switch checks that water is moving through the heater.
What the manual checks
If the pump is running, Pentair says this usually means the filter or skimmers need cleaning. Some filters need backwashing. Its chart then checks the water flow, the switch and its wiring.
What you can safely note
Is the pump running? When was the filter last cleaned? Clean it only by the steps in the filter's own manual.
Technician's part
If the message stays after filter care, Pentair says a qualified technician should check the system.

ERR HLS

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The high limit switch is open. It stops the burner when water in the heater gets above 135°F after its first pass.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair's chart checks the water flow and the water coming in first. Then it checks the heater's own water controls, the switch, and the heat exchanger (the tubes that heat the water) for a blockage.
What you can safely note
Is the pump running? Is the filter due for cleaning? Did you hear water boiling inside the heater?
Technician's part
A technician runs the tests on the chart. Do not reset the heater to make it run.

ERR IGN

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The heater could not light the burner.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair's chart checks the fan, the gas pressure and whether the heater can sense a flame. Each one takes a different test.
What you can safely note
If you smell gas, leave first and call from a safe place. If not, note whether you heard the fan start.
Technician's part
Gas pressure, flame and ignition tests are technician work.

ERR AFS

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The air flow switch is open. The fan (blower) is not on, or air through it is blocked. If air flow comes back within 60 seconds, the heater goes back to normal.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair's chart first asks if the fan runs. It then checks for a blockage at the air intake, the heat exchanger or the exhaust, an exhaust pipe that is too long, and the switch tubing and wiring.
What you can safely note
From where you stand, can you see leaves, a nest or stored items on the heater top or its vents? Do not reach in or clear a vent yourself.
Technician's part
A technician checks the fan, the switch, its tubing and the vent.

ERR AGS

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The automatic gas shutoff is open. Water after its second pass through the heater is above 140°F. The front buttons stop working after this message.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair uses the same chart as for ERR HLS. It starts with the water flow and the water coming in.
What you can safely note
Is the pump running? Write down how long the heater had been on.
Technician's part
A technician finds why it tripped. Do not reset the heater to make it run.

ERR SFS

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The stack flue is too hot. That is where hot gases leave the heater. On these models it means above 480°F. The front buttons stop working.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair's chart checks the gas supply, the exhaust sensor and its wiring, and the heat exchanger for leaks, scale, soot or low water flow.
What you can safely note
If you see smoke or fire, leave and call 911. If not, write down the message and when it showed.
Technician's part
Every check on this chart is technician work.

E01

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The water temperature sensor reads as open, like a broken circuit.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair's chart checks the sensor wiring first, then the sensor.
What you can safely note
Write down the message and when it showed.
Technician's part
A technician tests the wiring and the sensor.

126

Fault
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The water temperature sensor reads as shorted.
Manual warning
Pentair says not to run the heater with this message. Use the guide's steps to turn off the gas, then have a qualified technician check it.
What the manual checks
Pentair's chart checks the sensor wiring first, then the sensor.
What you can safely note
Write down the message and when it showed.
Technician's part
A technician tests the wiring and the sensor.

RS485 Control

Setting
Applies to
MasterTemp 175 to 400 and Max-E-Therm screen
What it means
The heater is linked to a Pentair IntelliCenter control. The heater's own buttons then only light up its screen.
What the manual checks
Pentair says heater alarms and errors show on the IntelliCenter Status Home screen.
What you can safely note
Write down what both screens show.
Technician's part
Ask about the control link when you call.

The same table also lists E05 and E06, which are about the exhaust sensor. Pentair also lists messages that show only on an IntelliCenter screen. This page does not explain those. Copy them exactly.

Back to models

MasterTemp 125

The MasterTemp 125 has its own guide. Its table on page 44 uses the same ten message names and notes as the larger MasterTemp. Its warning on page 41 names the same nine messages that mean do not run the heater. Use the 125 guide's own charts, not the larger heater's pages.

Source: MasterTemp 125 guide (P/N 475000 Rev E)

Back to models

ETi 400

The ETi 400 is a condensing heater. It makes acidic water, called condensate, as it runs. Pentair recommends treating that water before it drains.

SERVICE SYSTEM light

Fault
Applies to
ETi 400 front panel
What it means
Not enough water is flowing to the heater.
What the manual checks
If the pump is running, Pentair says this usually means the filter or skimmers need cleaning. Some filters need backwashing.
What you can safely note
Is the pump running? When was the filter last cleaned? Clean it only by the steps in the filter's own manual.
Technician's part
If the light stays on after filter care, Pentair says a qualified technician should check the system.

SERVICE HEATER light

Fault
Applies to
ETi 400 front panel
What it means
There is a fault in the heater or its controls.
Manual warning
Pentair says to shut the heater down with its steps to turn off the gas. Then have a qualified technician check it.
What the manual checks
Pentair does not name one cause for this light.
What you can safely note
Write down any code on the display and whether the HEATING light was on.
Technician's part
Finding the cause is technician work.

HEATING light

Status
Applies to
ETi 400 front panel
What it means
Steady means the burner is firing. Blinking means the heater is calling for heat but not firing.
What the manual checks
If this light is on but the burner does not come on, Pentair says one of the service lights should come on.
What you can safely note
Note whether it is steady or blinking, and whether a service light is on too.
Technician's part
If a service light comes on, use that card.

RNC

Reminder
Applies to
ETi 400 front panel
What it means
A reminder to service the condensate neutralizer cartridge. That cartridge treats the acidic water. RNC is not an ignition fault.
What the manual checks
Pentair says to contact a qualified technician or service agency to service the cartridge.
What you can safely note
Copy the screen and the full model.
Technician's part
Cartridge service is technician work on this model.
Source
ETi 400 guide (P/N 475349 Rev E), pages 38 and 53

The ETi 400 table also lists short codes such as PS, HLS, AFS, AG1, AG2, IGN, FS, tf, E01, E05, E06 and 126. Their limits are not the same as the MasterTemp table. This page does not explain them. Copy them exactly.

Back to models

ETi 250

The ETi 250 uses many of the same message names as the MasterTemp. Some limits are different, so read its own table.

ERR SFS

Fault
Applies to
ETi 250 screen
What it means
On the ETi 250, the exhaust is above 170°F. On a MasterTemp, the same name means above 480°F.
What the manual checks
Use the ETi 250 chart, not the MasterTemp chart.
What you can safely note
Write down the full model so the right table is used.
Technician's part
A technician follows the ETi 250 guide.

ERR CFS

Fault
Applies to
ETi 250 screen
What it means
The condensate float switch is open. Water from the exhaust has risen too high, so the heater shuts down.
What the manual checks
Pentair says this switch opens if a blocked drain hose or neutralizer cartridge makes the water overflow.
What you can safely note
From where you stand, is water pooling near the heater base? Do not open the heater.
Technician's part
A technician clears the drain path and checks the switch.
Source
ETi 250 guide (P/N 476361 Rev B), pages 16, 18 and 50

RNC or REPLACE

Reminder
Applies to
ETi 250 screen
What it means
A reminder to replace the condensate neutralizer cartridge after 1,000 hours of heating, when that alert is turned on. The guide words it two ways. Page 11 says the screen shows REPLACE. Page 12 says a flashing RNC message shows.
What the manual checks
Pentair recommends replacing the cartridge and then resetting the timer.
What you can safely note
Copy exactly what the screen shows.
Technician's part
Ask a technician to change the cartridge.
Source
ETi 250 guide (P/N 476361 Rev B), pages 11 and 12

The ETi 250 table also lists ERR PS, ERR HLS, ERR AFS, ERR AGS, ERR IGN, ERR FT, E01, E05, E06 and 126. Read their meaning in the ETi 250 guide, not the MasterTemp guide.

Back to models

Not listed? Your message may still be real. Do not borrow a meaning from another model. Write down the exact words and the full model, and give both to Colin.

Planning a new Pentair heater: questions to settle

These questions come from Pentair's installation guides. They show what the installer must check. They are not steps to do yourself. Gas, vent and wiring work belongs to a qualified installer, under local code.

Natural gas or propane?
A MasterTemp is built for one fuel. The nameplate shows which. Pentair says only a qualified technician should convert it from one fuel to the other.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), page 6
If it uses propane, is the spot low or closed in?
Propane is heavier than air. Pentair says not to put a propane heater in a pit or low spot where gas could collect. Local code sets how far it must be from tanks.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), page 20
Outdoors, or indoors or in an enclosure?
Outdoors, a MasterTemp uses its built-in vent. Indoors it needs a vent kit, and the exhaust pipe must be metal vent rated Category I or III. Pentair says not to use PVC for that exhaust pipe.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), pages 6 and 24
Is there enough room around it?
The guide lists the space needed from walls, roof edges and openings into the house.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), pages 20, 21 and 22
Will sprinklers, roof runoff, salt air or strong wind reach the pad?
Pentair warns against long exposure to sprinkler spray or roof runoff, and against salty or very wet settings. It sells a bolt-down bracket kit for hurricane areas.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), page 20
Is it a condensing ETi?
The ETi 250 and ETi 400 make acidic water as they run. It must drain the right way, and Pentair recommends treating it first. Their vents are a different type from a MasterTemp's. An existing vent must meet the ETi guide or be replaced.ETi 400 guide (P/N 475349 Rev E), pages 28 and 38; ETi 250 guide (P/N 476361 Rev B), pages 30 and 40
Does the pump move a lot of water?
Pentair calls for a manual bypass valve around a MasterTemp when the pump flow is above the heater's limit. The installer checks the pump and the plumbing.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), page 12
Will a control system run it?
A MasterTemp can link to a Pentair IntelliCenter by an RS-485 cable. Name any control you have when you call.MasterTemp 175 to 400 guide (P/N 472592 Rev Q), page 37

Safety first, then photos

If you smell gas, see smoke or fire, or think carbon monoxide is possible, do not stay to take photos or run the heater. Move everyone away. Then call from a safe place. If you see smoke or fire, call 911. If carbon monoxide is possible, get to fresh air and call 911. If you smell gas and the heater uses natural gas, call 911 and your gas utility. If you smell gas and the heater uses propane, call your propane company, or 911 or the fire department.

When none of that applies, send a wide photo of the heater. Then send a close photo of any outside label or display you can already see. Add the serial number or fuel only if a label shows it. Do not guess the fuel from a pipe or tank nearby. Do not open any panel.

What a repair visit costs

A repair visit is a service call. You hear the fee before the visit. It pays for Colin's first hour of on-site checking and testing. It is due even if you turn down the repair. After that you get a total-price quote, good for 15 days from the date it is issued. No repair or installation work starts until you approve that price. Full fee and quote rules

Call Colin at 941-961-9337, Monday to Friday, 8 AM to 5 PM.

Sources and limits

The message lookup and install planning notes above come from these manufacturer manuals. Each card and answer names its manual and page. The manual copies used here were retrieved on the date shown. A manufacturer can change a manual later, so check the manual for your own heater too.

Not covered on this page

  • UltraTemp ETi hybrid heaters, because Suncoast does not work on heat pumps.
  • Older MiniMax heaters. No MiniMax manual was used for this page.
  • Messages that show only on a Pentair IntelliCenter screen.

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Talk with Colin

Tell Colin what the heater is doing.

Call Colin941-961-9337