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Home Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas with Electrical Plug-In Cord - 125,000 BTU - EC-462025
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Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas with Electrical Plug-In Cord - 125,000 BTU - EC-462025

Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas with Electrical Plug-In Cord - 125,000 BTU - EC-462025

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  • 82% Energy Efficiency is Highest in its Class
  • 1-1/2" Plumbing-Ideal for Smaller Bodies of Water up to 15,000 Gallons
  • High-Performance, Affordable Heating with Premium Features
  • Pre-Mixed Combustion Technology for Ultra-Fast Heat-Up
  • Easy-to-Use, Digital Display Makes Programming and Monitoring a Cinch.
  • Online part number EC-462025 is the direct replacement for part number 461061
Purchase Options
  • Pentair Sta-Rite 4x6 Metal Flue Collar for Indoor Vertical Venting - Negative Pressure for Distance Less Than 8' | 77707-0076
    Indoor Vertical Venting - Negative Pressure 4x6 Metal Flue Collar for Distances Less Than 8' | 77707-0076

  • Pentair Sta-Rite 4x8 Metal Flue Collar for Indoor Vertical Venting - Negative Pressure for Distances Over 8' | 77707-0077
    Indoor Vertical Venting - Negative Pressure 4x8 Metal Flue Collar for Distances Over 8' | 77707-0077

  • Pentair 4" Stainless Steel Appliance Adapter for Horizontal or Vertical Positive Pressure by Heatfab | 77707-0086
    4" Appliance Adapter Horizontal or Vertical Venting, Positive Pressure by Heatfab | 77707-0086

  • Pentair 4" Stainless Steel Appliance Adapter for Horizontal or Vertical Positive Pressure Venting by Z-Flex | 77707-0087
    4" Appliance Adapter for Horizontal or Vertical Positive Pressure Venting by Z-Flex | 77707-0087

  • Pentair MasterTemp 125 Propane to Natural Gas Conversion Kit | 461062
    Pentair MasterTemp 125 Propane to Natural Gas Conversion Kit | 461062

MasterTemp® 125 High Performance Heater
Introducing! The High-Efficiency, High Technology Heater for Bodies of Water up to 15,000 gallons 
The remarkably affordable new MasterTemp 125 heater gives you the energy savings and advanced operating features that were only available from much larger heaters. With its revolutionary pre-mixed gas combustion technology, the MasterTemp 125 heater offers 82% thermal efficiency - the highest of any heater in its category. Its 1-1/2" plumbing is ideal for smaller applications, including aboveground pools, spas and inground pools up to 15,000 gallons. Featuring the first ever rotating, digital display offered in its class, the MasterTemp 125 heater provides valuable information conveniently and at the touch of a button. Plus, its lightweight, compact design makes the MasterTemp 125 heater easier to install than any other heater in its class - reducing labor costs which saves you money.
New Improved Rodent Resistance for the MasterTemp High Performance Heater
The engineers made improvements to reduce gaps and eliminate access points, including advancements to the heater base, all exterior side panels and louvers, the gas valve and water manifold openings, the exhaust opening and the exhaust cover. These subtle, but important, design changes add up to a better heater, from every angle.
In addition to the new rodent resistant improvements, the features and benefits of a MasterTemp High Performance Heater include:
  • Enhanced LCD display and diagnostics include easy to display and front-facing error messages and icons
  • Best-in-class energy efficiency
  • Eco-friendly certified for low, NOx emission and outperforms industry standard
MasterTemp 125 heater features include:
  • 82% energy efficiency is highest in its class.
  • 1-1/2" plumbing - ideal for smaller bodies of water up to 15,000 gallons.
  • High-performance, affordable heating with premium features.
  • Pre-mixed combustion technology for ultra-fast heat-up.
  • Easy-to-use, digitial display makes programming and monitoring a cinch.
  • 125,000 BTU rating.
  • Available in natural gas or propane gas.
  • 120v electrical.
  • Lightweight - easy to handle and ship.
  • Certified for low NOx emissions.
  • Certified for Direct Air Intake with PVC Pipe.
  • Certified for outdoor and indoor vented installations.
These installations instructions are designed for use by qualified personnel only, trained especially for installation of this type of heating equipment and related components.
Some states require installation and repair by licensed personnel. If this applies in your state, be sure your contractor bears the appropriate license.

Brand: Pentair
BTU Rating
Gas Type
Q & A
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 45 questions Browse 45 questions and 92 answers
How much would it cost to run monthly with a smaller underground pool less than 10000 gallons?
Julio G on May 17, 2016
What is the typical annual cost of operating this unit?
stacie g on Sep 9, 2015
BEST ANSWER: 500 a month ,.. It depends on how much u use it,. We turn it off until we want to use it,. It heats our 5000 gal pool in about 3-4 hours
how many gallons of propane does it consume in 8 hours ?
A shopper on Feb 14, 2016
BEST ANSWER: mine used one hundred pound tank which is 23 gallons about every three weeks
pool is 15'x35'. what size natural gas heater do I need?
justjudy on Jun 24, 2016
BEST ANSWER: you need to figur out how many gallons of water first. there are calculators for that on line to figure it out. you have to add measurements for deep end as well as shallow end. the pentair 125 works well on 15,000 gallon pools.
Does it need to be stored indoors?
A shopper on Sep 4, 2016
BEST ANSWER: No it doesn't. I live in Missouri with cold winters. I cover it with plastic sheeting and duct tape when I close the pool. I also blow the water out of the heater with a pool water line blaster so it won't freeze up and get damaged. The heater was a great addition for our pool. Easy to use and take care of. Good luck.
All I want to do is heat a 515 gallon in ground spa. I live in Tampa and have solar for the pool. Is there a temperature rise chart at various starting and ending degrees with time to heat?
Tony A on Mar 18, 2017
BEST ANSWER: I am sorry. We bought the heater for a 17000 gallon pool and we live in Michigan so I don't have an answer for Tony.
I have the water inlet/outlet on the same side as the electrical and gas inlet. How can I hook up to this unit?
A shopper on Sep 24, 2016
BEST ANSWER: The manifold can be turned around by spinning the top of the heater.
Is this heater (Pentair Mastertemp 125- Propane) new or rebuilt?
A A on Dec 7, 2016
BEST ANSWER: New. We use it to supplement our solar heater for a 10,000 gallon pool and it does a very good job. when temps are in the 50s-70's pool temp can stay up to 82 degrees on about $100 propane/week or less.
What size wire do I need?
Joe D on Feb 8, 2016
BEST ANSWER: The electronics will run on a 15 amp circuit which is typically 14.2 with G but I ran a 20 amp with 12.2 W G If you are going to run an extension cord to a prewired unit (one with a plug) make sure it is at least 14.2 W G
i have 3/4" gas line 75' direct. Will this be adequate for unit ?
brian on Apr 21, 2016
BEST ANSWER: You should have no problem as long as you have a good supply of LP. we use ours to get the temperature a few degrees higher. with a 100 pound tank.
What size heater do you need for a 25000 gal pool?
WILLIAM S on May 1, 2017
BEST ANSWER: I got the Pentair 125 for my 15 ft round above ground pool and it heats it with no problem. I love it. I don't know about that large a pool - sorry.
Does this heater come with everything we need to install and use it or are there additional items I need to buy?
Allison A on Mar 2, 2017
BEST ANSWER: We needed to purchase adapters that attach the heater to the pool filter and we had to have gas lines installed to hook it to our propane can"pig." It was definitely worth it since we live in Northern Michigan and it can be really cold here. Enter
What size propane tank is needed?
Mike H on Apr 14, 2019
BEST ANSWER: I currently use a 500 gallon tank . I also fuel my water heater for the house and whole house generator. I run the heater every day because we are in a high altitude area that is cool in the summer.

100gallon is plenty big enough.
outside vent kit for Pentair 125 ?
A shopper on Apr 1, 2016
BEST ANSWER: This is a great little unit. Mine is outside so no need for a vent kit for me. No problems with it easy to use
Can I run this on a 20 lb tank?
A shopper on Jun 11, 2018
BEST ANSWER: No, you need no less than a 100 lb tank. I have 2 100 lb tanks. When I had the Pentair heater installed March 13th, I heated my 15ft round pool and I keep it at 86 degrees. Your usage depends where you live and how warm you want it. A solor cover will help a lot.
Will this work for a 24 foot above ground?
A shopper on Apr 12, 2017
BEST ANSWER: I bought this heater in 2016 for use on a 16x32 above ground pool. Should have done this years ago. This heater warms my pool in a very short time. I do not leave this heater on all the time. I turn it on in the morning if the water temp is low and shut it off in the later part of the day with a solar cover at night. Best thing I ever did. Have tried solar heaters in the past that do not compare. Plus I hooked up a 100 gal. propane tank instead of using natural gas. This made much less work and I did not use a full tank in the entire season from June to early September.
i have a 1 inch gas line will this heater work?
Bryan M on May 19, 2019
BEST ANSWER: Really depends on size of heater and how far away the tank is and water table, download a copy of manual and in back there will be all info you need. Unless it’s natural gas. Still I would check the manual.
Do you need a gas line for the heater, and an electrical outlet and does it use propane in a tank?
A shopper on Mar 19, 2021
BEST ANSWER: Propane tank and plug I never used it still on the box
Is this product compatible with inground pools?
L S on Apr 22, 2017
BEST ANSWER: I use it for an above ground pool 18 foot round 54 inches deep 8000 gallons works great heats the pool up to 80 degrees after four hours of running I use propane the cost last year for the 4 month season was $120.
What is the difference between Natural gas and Propane gas ??
A shopper on Jun 21, 2021
BEST ANSWER: Natural gas is piped to your house from a gas supply company, and has a meter installed at your house. Propane gas is supplied from a tank placed on your property, and a truck will deliver propane to the tank. If you have natural gas available on your property, it is much cheaper to operate a pool heater on natural gas.
Is this heater suitable for salt water?
A shopper on May 21, 2018
BEST ANSWER: Yes I haves used these on salt water pools but when not in use make sure the heating element and plumbing is thoroughly cleaned. Check with manufacturer on warranty. Some manufacturers will not warranty salt water heaters unless there is a option for heaters with elements that will withstand salt. And make sure your salt system is working correctly and the water is properly balanced.
What is the difference between with cord and without cord?
A shopper on Apr 11, 2018
BEST ANSWER: With cord plugs in a 110 wall receptacle and with out needs to be hard wired into a systems controller or a timer. I plugged mine in so I can unplug it if I want to.
What is the cord length?
A shopper on Jul 21, 2017
BEST ANSWER: The cord length is about 4 ft.
will this unit work on salt water pools ?
butch on Oct 5, 2016
BEST ANSWER: Sure; it's just water through a pipe. If chlorine doesn't kill it, a little salt won't hurt. Ur not filtering the Dead Sea, right?
How much a month do you spend on propane if you use a 100lb cylinder (about 24 gallons) and leave the heater on for 8 hours a day?
Lu J on Sep 28, 2016
BEST ANSWER: I only run the heater as I need to. I use a solar cover as much as possible. It cost me about one dollar for every degree I raise the pool temperature. I spend around $75.00 to $100 per season. We keep the water an average of 85 degrees all summer. Missouri has hot summers. Best pool investment I have made. Good luck!
I live above 5,500 ft., dose this heater need to be rejeted?
A shopper on Aug 1, 2016
BEST ANSWER: Sorry don't the answer to that.
Was simple hook up though and the only adjustment you have to possibly adjust would be the pressure switch. Which has to do with what level the heater is to the top of the pool water. The
manual shows how do that.
I have a pool pump room under my beach house which is on stilts. Is it OK to install a vented unit in this room?
Tom C on May 19, 2016
BEST ANSWER: The manual has instructions for this kind of installation. Venting is the key. Noxious fumes in the house are unfriendly.
Can I use the master temp 125 low w/electricity until I get the gas line in?
A shopper on Jun 20, 2020
BEST ANSWER: The heater does not have an electric heating element in it, it's strictly gas. But, you can get it with a propane kit where you can use propane bottles instead of natural gas to start. Then, when you get the natural gas line piped to it, sitch it over with the NG gas kit. This is what I did anyway. Depending on how much heating you're doing, the propane goes pretty quickly.
Will it work with a salt water/chlorine pool?
A shopper on May 21, 2020
BEST ANSWER: yes. We have a sand/salt filter and it works great!
How much is shipping?
A shopper on Sep 8, 2018
BEST ANSWER: Flat rate freight shipping is $165.
4.9 / 5.0
12 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Rated 5 out of 5
Unit Value
I installed this unit on my wife's pool that the solar unit would not adequately heat. We are at 7800 ft elevation , temp now about high of 73 day 49 night The unit took about 4 hrs to go from 62- 83. Next day 84 in 2 hrs. Pool is 10 x18 4 ft deep. Solar cover at night

Also the salesman that helped me was outstanding knew his stuff and sold me the correct unit Great place to do business with.
September 11, 2016
over 5 years ago
Rated 5 out of 5
Propane pool heater Pentair Master Temp 125
The heater does a good job heating my 8000 gal pool using 1 gallon of propane an hour takes about 4 hours to the raise the temp 5 degrees no more complaints from the grandkids that the pool water is to cold.
August 22, 2016
over 6 years ago
Rated 5 out of 5
so far this has worked well . I did have a problem with the temperature controller but I replaced I replaced it my self
December 7, 2016
over 7 years ago
Rated 5 out of 5
Works great!
I can easily warm our pool up to 90 degrees which my wife and kids love! Worked perfect right out of the box. Overall is it a top notch heater!<br>
August 2, 2015
Rated 5 out of 5
Excellent Pool Heater
It does exactly what it should and was easy to install. Good installation manual. It heats my 12,000 gallon pool at about 3 degrees per hour. Great value, solid construction.
June 5, 2018
over 3 years ago
Rated 5 out of 5
Pentair pool heater
This is a great heater we just got it hooked up and it is wonderful. It has taken the pool water from 47 degrees to 80 degrees in about 20 hours. We are impressed with how quickly it took the temp up. Thanks I would recommend the heater to everyone.
March 24, 2018
over 4 years ago
Rated 5 out of 5
Great heater
I love this thing. Works great.
No problems with it.
January 17, 2019
over 5 years ago
Rated 5 out of 5
Looks like a winner
This unit looks great by our pool & doesn't take up much space. It was an easy install. The temperature display eliminates having to find the thermometer. Shipping was during a snow storm but arrived on time. So far so good.
May 10, 2018
over 4 years ago
Rated 5 out of 5
Awesome pool heater for the money!!
I have had several pool heaters, this is an excellent heater for the money… They can bring my pool up 5° in a couple of hours which is all I need .
June 30, 2019
over 2 years ago
Rated 4 out of 5
Pentair 125btu
Have not put it thru all of its capabilities yet. Great so far no complaints.
August 21, 2019
over 2 years ago
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Register your Pentair product online at www.pentair.com.

You've always been able to count on the quality and long service life of Pentair products. Pentair uses state of the art workmanship, materials and manufacturing processes to create the most innovative pool and spa equipment anywhere. And now Pentair products can deliver even more value and peace of mind, because Pentair offers extended warranty coverage on select products that are installed by a qualified installer*.
While the majority of Pentair products are covered by a sixty- (60) day warranty, a select number of products qualify for extended warranty coverage.
Select Bundled Products: applies to purchases and qualified installation of a minimum of a pump and filter, and one or more of the following: heaters, heat pumps, control systems, automatic cleaners, lighting, salt chlorine generators or UV sterilizer**
*Note: Qualified Installer - Defined as a licensed professional who charges a fee for his services, and possesses a business license, contractor's license and/or resale permit. Common examples of a "qualified installer" include: Swimming Pool, Home Repair or Landscape Professional; Plumber or Electrician; General Contractor; Heating and Air Conditioning Specialist.
**Note: Bundled products - must be purchased on the same invoice and installed at the same time. If any product within a bundle is ineligible for the bundled warranty coverage then all products within the same bundle will be disqualified from receiving the three (3) year extended warranty coverage for bundled products.
TradeGrade products must be purchased from a retail store (brick & mortar), pool builder or pool service company to receive a one-year, two-year or three-year warranty. If purchased online will only receive a sixty-day limited warranty. View the list of TradeGrade Products.
Ecommerce (EC) products: Products purchased from an Authorized Pentair Online Reseller (products beginning with EC-) receive a one (1) year (parts only) warranty from the date of purchase. The exceptions are: IntelliChlor cells and IntelliFlo SVRS pumps which receive a two (2) year warranty. EC products are not eligible for the bundled three (3) year extended warranty.
Visit www.pentair.com to submit your product warranty registration.
This information was updated on 11/19/2021. For the most current information and full warranty policy please visit www.pentair.com/warranty.

 Adobe Acrobat PDF Warranty Information
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