MasterTemp Heater 400,000 BTU - NG w/ Electric Ignition Low NOx HD ASME - 461021


Model # 461021

By Pentair Pool Products



Model # 461021

Warranty 2 YEARS & LABOR

Alternate Part #'s PEN461021

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. 

Heavy-Duty (HD) unit with cupro-nickel exchanger stands up to the harshest of applications, like low pH, high flow or heavy use.


  • 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.


?     Asked on 12/9/2020 by david b fernald

How long to warm pool from 60 to 80 degrees? Pool is 30x16 6ft at deep end. thanks, d

A  Answered on 12/9/2020 by InyoPools Product Specialist Joe S.

One of the most frequently asked questions we hear from pool owners is, “How long does it take to heat a pool?” This is an important question because it helps pool owners determine what size pool heater they need to purchase for their pool and how long in advance they need to start their heater so that it is warm enough to swim. Here is a blog to help answer your question.

?     Asked on 7/2/2020 by

Does this run on propane?

A  Answered on 7/2/2020 by InyoPools Product Specialist Lennox H.

Hi. This is a natural gas unit. The propane unit model number is 460776