MasterTemp 400K BTU NG High Performance Pool and Spa Heater - 460736



Part # EC-462028

By Pentair Pool Products

  5 Average  



Part # EC-462028

Warranty 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.

Manufacturer Code 460736

Alternate Part #'s 460736, EC462028, PENEC-462028, PUR-15-2012

Product Description

The MasterTemp High Performance Heaters offer all the efficiency, convenience, and reliability features you want in a pool heater, plus a lot more. As easy to use as your home heating system, plus, user-friendly indicator lights and troubleshoot icons makes system operations and monitoring a snap. The compact design and super-quiet operation won't intrude on your poolside leisure time. 


  • Superior “Best-in-Class” energy-efficiency
  • Rotating digital display allows for easy viewing, rotate to 3 positions so there’s no need to reverse the header, simplifying installation
  • Quick-change orifice allows easy conversion of gas sources
  • Compact design (21" L x 21" W x 28" H) is easy to retrofit, no matter what the space challenges
  • Tough, rustproof exterior handles the heat and weathers the elements
  • Built-in carrying handles for easy transport
  • Certified for outdoor and indoor installation
  • Certified for Low NOx emissions

Standard copper heat exchanger 84% efficient. Heavy-duty (HD) cupro-nickel heat exchanger 82% efficient.

Product Specifications

400,000 BTU
0-9,000 ft.
Heat Exchanger:
Special Feature:
Low NOx Emission

?     Asked on 10/12/2020 by

Are these commercial grade units?

A  Answered on 10/14/2020 by InyoPools Product Specialist Joe S.

Good day,Model 460736 would not be a commercial unit. You would need to order the MasterTemp Heater 400,000 BTU - NG w/ Electric Ignition Low NOx HD ASME - 461021.

?     Asked on 4/17/2020 by Luke Hoffman

the heater would be placed inside, what kind of ventilation do I need?

A  Answered on 4/17/2020 by InyoPools Product Specialist Patrick P.

Hi Luke, Could you let us know if you will be venting vertical through the roof or horizontally through a side wall?

  • Commented on 4/17/2020 by Product Owner

    it will be going through a wall the heater will only be a foot or 2 away from the exterior wall

?     Asked on 4/3/2020 by

how many BTU for 10x28 pool

A  Answered on 11/12/2020 by InyoPools Product Specialist Megan C.

The depth and shape of the pool will be needed to determine the total gallons or surface area of the pool. We will need the depth on the deep end and shallow end. Hypothetically, if the pool is 10' x 28' x 5.0' (Average Depth) x 7.5 (Rectangle) = 10,500 total gallons. The minimum BTU size for a  heater is 88,000 BTUs. If you select a heater with the minimum size, it would take approximately 1.5 hours to raise the temperature in the water by 1-degree. This is with the use of a solid solar cover or Natural Chemistry Cover Free 80% of heat loss is due to evaporation. Please see How Long Does It Take to Heat a Pool? 

?     Asked on 1/21/2020 by RAUL

We are replacing a 400K BTU heater with a new Haward, or Pentair 400k btu. How do I check to see if the current meter can handle this unit? It worked fine with the old on, but I've heard the new units need more gas. The old line was 3/4" off the meter 1" underground and 3/4" intothe heater.

A  Answered on 1/21/2020 by InyoPools Product Specialist Lennox H.

Hi, Raul. You will have to reach out to the gas company so that they can check the meter. New units do not use more gas than older units. I 1" gas line will be sufficient if the unit is with 25' of the meter. See the Gas Connection info on page 20 of the Pentair Mastertemp Heater Owners Manual.

?     Asked on 11/18/2019 by

I currently have a Hayward heater and Hayward control panel. Will the Pentair heater work with my existing Hayward control panel?

A  Answered on 11/18/2019 by InyoPools Product Specialist Megan C.

Hi. It can control the heater, however, it will only be able to turn the heater off/on. You will not be able to fully control this MasterTemp unit.

  • Commented on 5/25/2020 by Product Owner

    Can you clarify what it means to not control the master temp unit? What is the master temp unit?

    • Commented on 11/6/2020 by InyoPools Product Specialist Megan C.

      The Master Temp is the Pentair manufacturers Natural Gas and Propane heaters shown here The control they are mentioning is an automation system either controlled via WiFi or RF Frequency, they power the pumps, lights, heaters, etc. It is best to use the same manufacturers with automation systems, certain pumps and lights require the same manufacturer. It depends on which Hayward automated system one has, if you can only use on/off or if you will be able to change the temperature settings too.

?     Asked on 11/2/2019 by Lyn

What is the efficiency of this heater?

A  Answered on 11/4/2019 by InyoPools Product Specialist Lennox H.

Hi, Lyn. This unit is rated at 84% efficiency. 

?     Asked on 2/9/2019 by tim

i have a 3 yr old master temp 400 water is coming out of air blower is my heater done for ?

A  Answered on 2/13/2019 by InyoPools Product Specialist Michelle B.

Hello, We recommend contacting the manufacturer on that question, you can reach them at 1-800-831-7133.

?     Asked on 1/25/2019 by

I cant adjust temp on control panel...the heater is on but up and down temp control stopped working

A  Answered on 1/29/2019 by InyoPools Product Specialist Joe S.

Check Fireman’s Switch circuit connections (time clock, wiring, external controller relay).

?     Asked on 1/12/2019 by Steven Conway

I need to replace a Pentair MinMax NT. Currently using a Goldline system controller. Are these two compatible?

A  Answered on 1/15/2019 by InyoPools Product Specialist Lennox H.

Hi, Steven. This heater can be used to replace the Pentair MinMax NT and is compatible with the Goldline Automation system. You can also use the Universal H-Series Low NOx Heater 400K BTU - NG - H400FDN unit.

?     Asked on 12/10/2018 by Tom

is this heater compatible with controls to operate the heater through your internet connection? does Pentair make such controls?

A  Answered on 12/11/2018 by InyoPools Product Specialist Lennox H.

Hi, Tom. Using one of these Pentair Pool & Spa Automation Systems

?     Asked on 8/16/2018 by Roberto

Is this Master temp heater a compatible replacement for Master temp 460775?

A  Answered on 8/25/2018 by InyoPools Product Specialist Lennox H.

Hi, Roberto. It's not you will need to get the MasterTemp Heater 400,000 BTU NG w/ Ele Ign, Low NOx, ASME - 460775 unit. 

?     Asked on 7/16/2018 by Wray

Are the master temp heaters compatible with the Jandy aqualink ???

A  Answered on 7/16/2018 by InyoPools Product Specialist Lennox H.

Hi, Wray. The Aqualink will be able to control the Pentair MasterTemp. It will provide basic on/off functions. 

?     Asked on 6/6/2018 by Dave

I am replacing a Hayward 300,000 btu heater and the system is piped with 1-1/2" pipe. It is not possible to re-pipe for 2", will this heater work with 1-1/2" plumbing?

A  Answered on 6/7/2018 by InyoPools Product Specialist Lennox H.

Hi, Dave. You can re-plumb with 2" pvc or use 1-1/2" pvc. Using 1-1/2" you will have to use a reducer at the heater. 

?     Asked on 4/5/2018 by Mike

Whats the difference between the Pentair # 460805 and Pentair 460736 ?

A  Answered on 4/5/2018 by InyoPools Product Specialist Kevin G.

Hello, the 460805 is the heavy duty version with a cupro-nickel heat exchanger. 

?     Asked on 2/2/2018 by

is this heater Pentair MasterTemp 400K BTU ASME Cupro-Nickei natural Gas

A  Answered on 2/5/2018 by InyoPools Product Specialist Lennox H.

Hi. This is not an ASME Cupro-Nickel unit, you will need Product # 461021.  

?     Asked on 1/29/2018 by dan

Can you ship Pentair master temp high performance NG heater Pentair #460805 to California & what is the total cost delivered to my residence? It would be Credit card charge.

A  Answered on 1/29/2018 by InyoPools Product Specialist Michelle B.

Hello Dan, We can ship to California. The shipping would be free. 

?     Asked on 1/25/2018 by

weigth pentair 460737

A  Answered on 1/25/2018 by InyoPools Product Specialist Lennox H.

Hi. The carton weight of this unit is 136 lbs. 

?     Asked on 11/30/2017 by Cap'n Dan

Does this model work with propane? What voltage electricity does it require?

A  Answered on 12/1/2017 by InyoPools Product Specialist Lennox H.

Hi, Cap'n Dan. This specific Model 460736 will not operate using propane, you will need Model # 460737. They can operate using either 120 or 240 volts.

?     Asked on 11/16/2017 by

What is weight of this unit?

A  Answered on 11/16/2017 by InyoPools Product Specialist Kevin G.

According to the Pentair product catalog, this product has a carton weight of 136 pounds.

?     Asked on 6/22/2017 by GERALD RUSSONIELLO

plumbing inspector wants a pressure relief installed on heater, I don't see a port for it . what do you recommend ?

A  Answered on 6/23/2017 by InyoPools Product Specialist Lennox H.

Hi, Gerald. On page 18 of the Pentair Mastertemp Owners Manual provides the details of installing a pressure relief valve on this unit.

?     Asked on 6/1/2017 by Jim H

We have a 15 x 30 pool with a 4 person spa attached. Is this a good heater for this kind of application? Thanks!!

A  Answered on 6/7/2017 by InyoPools Product Specialist Lennox H.

Hi, Jim. A 400,000 BTU heater will be sufficient to heat a 15'x30' pool and a spa.

?     Asked on 5/22/2017 by

I know I need a 400,000 BTU heater for a large inground pool near Chicago. My pool contractor years ago put in a Pentair heater w/ all other Pentair related pool equipment components (filter tank, salt exchanger, etc.,). I'm in need of a new heater and considering Raypack or possibly staying with Pentair. Is one brand better than the other ? and/or is it necessary or best I stay with Pentair since all my other items are Pentair ? A licensed-brand contractor would install the new heater, not me

A  Answered on 5/29/2017 by InyoPools Product Specialist Lennox H.

Hi. One brand is not better than the other, you can stick with Pentair if you have the same unit so that a major install is not required. These unit are required to be professionally installed according to the manufacturer.

?     Asked on 4/17/2017 by Jhon

Que cantidad. De gas y e le electricidad WK/H consume por hora este calentador.

A  Answered on 4/18/2017 by InyoPools Product Specialist Scott W.

Here is some information on the cost of running a pool heater.

?     Asked on 12/24/2016 by RAY WILKES

I have a pentair master temp 400 natural gas pool heater and I need to replace the lower sensor on the left side and it is copper colored .Can you supply ?

A  Answered on 12/28/2016 by InyoPools Product Specialist Adam Y.

Good morning Ray, I would need to know what kind of sensor or a part#. You can contact Pentair at 1-800-831-7133 and they can assist you in finding the correct part number.

?     Asked on 12/6/2016 by Jennifer Williams

I am considering purchasing a pool heater model number 460736 Mastertemp . I am wanting to know about any warranty the product comes with and the details. I will be installing in a home in Texas also would like to know how warranty issues will be dealt with if my client has a problem. Any warranty documentation and all details you can send me would be greatly appreciated. Jennifer Williams 432-349-4984

A  Answered on 12/6/2016 by InyoPools Product Specialist Scott W.

That is going to have a 2 year manufacturer's warranty. Any issues you can either give us a call if any issues occur or give Pentair a call for a representative in your area.

?     Asked on 10/13/2016 by

I have a 12,300 gallon pool in San Antonio, TX. What size heater do I need for water temp between 80-85 degrees during our winter months? Thank you.

A  Answered on 10/13/2016 by InyoPools Product Specialist Scott W.

The 400,000 BTU model is definitely going to be the most efficient due to the fact that you will not have to run it as long to get to your desired temperature. You would also be good with the 300,000 BTU model as well, 460734, you would just have to run it longer to get to your desired temperature.

?     Asked on 8/19/2016 by Pete

I am installing a Pentair 460775 MasterTemp. Which 2" half union do you recommend? Thank you.

A  Answered on 8/20/2016 by InyoPools Product Specialist Alex V.

Pete, I am not sure I understand your question. The heater comes with unions.

?     Asked on 8/16/2016 by Chris

I have a 37'x17' 5 1/2' deep pool with a 9' diameter spa connected. What size heater do I need? I currently have a Haywood 400k heater that just went out. Do I need a special kind of heater? Thanks

A  Answered on 8/16/2016 by InyoPools Product Specialist Scott W.

If you currently have a heater that is natural gas, that is what I'd go with. As far as the size, I'd recommend sticking with the 400,000 BTU unit for the size of pool you have. The Master Temp would be a good replacement for your current heater. Another good heater to look at would be the RayPak, part number 009219. They also have reinforced heat exchangers on specific models for people with saltwater pools, it makes it less corrosive. The heat exchanger is usually what goes first on heaters due to corrosion. The part number for the reinforced heat exchanger is 014941.

?     Asked on 6/26/2016 by John Paul

I am installing a used Pentair Master Temp 400 Pool heater and i need to know the part numbers for the items i need to install the heater inlet and outlet pvc water connections. I know they originally come with the heater, but i do not have them.

A  Answered on 7/2/2016 by InyoPools Product Specialist Lennox H.

Hi John, The Half Union 2" Slip (42001-0402) are the unions used with the MasterTemp Heaters.

?     Asked on 6/21/2016 by leeroy

master temp 400,000 what size gas line on the heater

A  Answered on 6/26/2016 by InyoPools Product Specialist Alex V.

Leeroy, The size of the gas line will depend on the distance from the meter. Page 20 of the manual illustrates this:

?     Asked on 6/15/2016 by Ralph

On line you do not show a Pentair Mastertemp 400k btu with cupro nickel. If you have it what is the cost

A  Answered on 6/16/2016 by InyoPools Product Specialist Lennox H.

Hi Ralph, The MasterTemp Heater-460805 is the equivalent with the cupro nickel heat exchanger.

?     Asked on 6/8/2016 by henry

if I have a 325,000 BTU I CANINSTALLED A 400,000 BTU IN SAME GAS LINE

A  Answered on 6/10/2016 by InyoPools Product Specialist Scott W.

I believe the gas piping is the same but I'd recommend giving Pentair a call to confirm. That number is 1-800-831-7133.

?     Asked on 9/11/2015 by Ange

What is the warranty from pentair for the mastertemp 400000 btu #460736? Does the warranty begin on installation date after registration?

A  Answered on 9/11/2015 by InyoPools Product Specialist Joe S.

The MasterTemp pool heater is sold with a limited factory warranty. Specific details are described on the warrantyregistration card which is included with the product. Return the warranty registration card after filling in the serialnumber from the rating plate inside the heate

?     Asked on 9/7/2015 by RAY WILKES

I have a MasterTemp 400 (natural gas) that was installed 21/2 years ago .It seems to have quit working.All of the electronics are working fine but it just won't come on and start heating.

A  Answered on 9/11/2015 by InyoPools Product Specialist Lennox H.

Hi Ray, You can have a service technician come out to inspect the unit or use the MasterTemp Installation & User Guide to self troubleshoot your unit.

?     Asked on 6/11/2015 by

I have a 40,000 gallon in ground pool. We are looking at a new pump and heater. Only have 1.5 inch plumbing, but can be replaced. 20ft of heading between intake and pump. Any recommendations on an ideal pump size (hp), plumbing diamter, and heater size (btu) for my pool? Thanks

A  Answered on 6/12/2015 by InyoPools Product Specialist Patrick P.

We would suggest a pump which can turn your pool over in an 8 hour period which would mean a pump which can output 85 Gallons Per Minute (GPM). One of my favorite pumps is the Jacuzzi Magnum and you would need the 1-1/2 HP Jacuzzi Magnum Pump. I would strongly suggest re-plumbing as much as you can with 2" pipe and make sure that you have at least 12 inches of straight pipe going into the inlet of the pipe, no 90's within 12 inches of the inlet. If you are replacing a heater you will want to double check the size of your current gas line as this determines how large of a heater you can use. If this is a new heater installation I would suggest a 400,000 BTU heater.

?     Asked on 6/10/2015 by Rohb

I have a 36,000 gal pool. What is the min BTU and Max BTU I need to have to heat this pool comfortably.

A  Answered on 6/10/2015 by InyoPools Product Specialist Patrick P.

For a 36,000 gallon pool I would suggest between a 300,000 - 400,000 BTU heater. If you are replacing a heater you would want to make sure your current gas line can handle the BTU size of the heater you select.

?     Asked on 5/28/2015 by Johnny

My pool is 16 x 37 with average depth of 5 feet. Do I need a 400k unit?

A  Answered on 5/29/2015 by InyoPools Product Specialist Patrick P.

Hi Johnny, normally we suggest a 1-1/2 degree temperature raise per hour and with your size pool this would be a 250,000 BTU Pool Heater. You could go with the 400,000 BTU heater if you want to heat your pool faster as the 400,000 BTU unit will give you a 2-1/4 degree temperature raiser per hour. The other thing you will want to consider is the size gas line you have to the heater as the 400,000 BTU unit requires a larger gas line than the 250,000. You can view a Pool Heater Gas Line Size Chart here (refer to 266 for the 250K BTU and 406 for the 400K BTU).

?     Asked on 4/22/2015 by Sandra Zurawski

Is the ventilation for this heater on the top or sides or both? Our pool components are housed behind a cabana and the roof results in rainwater pouring down….I'd prefer not have install a gutter (metal roof and expense) but I also don't want the water surging down on top of the heater and rusting it out. That is why our existing heater is not functioning. If the heater is bought on-line, is there any kind of warranty after our pool person installs it?

A  Answered on 4/24/2015 by InyoPools Product Specialist Wes B.

Hi Sandra, This Pentair Mastertemp ventilation system runs up from the side with the exhaust fan traveling  upward. Pentair makes a vent cover to protect it from the elements. The vent cover part number is (42002-0005s).

?     Asked on 2/28/2015 by David Jervis

How much does a MasterTemp 400,000 BTU NG weigh?

A  Answered on 3/2/2015 by InyoPools Product Specialist Robert M.

Hello David - The MasterTemp 400, 000 BTU heater weighs 136 pounds.

?     Asked on 2/13/2015 by Unknown

Voltage and amperage specs Master Temp 400,000 BTU

A  Answered on 2/16/2015 by InyoPools Product Specialist Hector F.

This heater can use either a 240 or a 120 volt power supply and a 15 amp circuit. Please refer to the manual here.

?     Asked on 2/7/2015 by Greg Rup

I have a 18' Round 54" deep pool. what pool heater would I need

A  Answered on 2/9/2015 by InyoPools Product Specialist Robert M.

Hello Greg - The 200k BTU MasterTemp would be sufficient for your pool size.

?     Asked on 1/6/2015 by Guest

What is the elevation rating for the Pentair MasterTemp heater?

A  Answered on 1/6/2015 by InyoPools Product Specialist Robert M.

This heater will work up to an elevation of 8,000 feet.

?     Asked on 10/24/2014 by JV

This unit will be enought for a 25 K gallons of water pool ?

A  Answered on 10/25/2014 by InyoPools Product Specialist Patrick P.

Hi JV - Yes this heater would be sufficient for a 25,000 gallon pool.

?     Asked on 1/16/2012 by Guest

Will a gas heater operate at the low speed of a dual speed motor?

A  Answered on 1/16/2012 by InyoPools Product Specialist Patrick P.

Probably not - Most gas heater will shut off at low GPM levels (20-40) to keep the heater cores from overheating - 20 for 200 BTUs, 40 for 400 BTUs. Depending on your pool system you might get these GPM levels at the low speed but generally these heaters must be run at the motor's high speed.


Est. Repair Time

Less than 1 hr

Tools Needed

Adjustable Wrench

Needed a new heater.

Written on 3/20/2021 by Guest

When I had my pool installed I also had the gas line installed so when I was able to purchase the gas heater I choose the 400 BTUI had it installed by a professional. heats up my spa within 20 minutes. it’s great and keeps the whole pool and a spa heated.

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