PER THE MANUFACTURER: THIS ITEM IS NOT AVAILABLE FOR SALE ONLINE
Model # SR400NA
Your Pool Heater Just Got a Whole Lot Smarter
Save money and energy with the Max-E-Therm High-Performance Heater. Long known for dependable, efficient heating, the latest Max-E-Therm adds smart connectivity, advanced ignition control, and an optional energy-saving automatic bypass to keep your pool ready whenever you are.
Key Features
Smart connectivity with automation systems for remote monitoring and control
Alerts pushed to smart devices for real-time heater status
Advanced ignition control module with flame strength sensor
Full-text digital display with intuitive diagnostics menu
Optional Smart Heater Bypass valve can reduce operating cost up to 35%*
Compact footprint — ideal for tight equipment pads
Polymer header design for superior corrosion resistance
Quiet operation and high thermal efficiency
Smart Connectivity & Control
The Max-E-Therm integrates seamlessly with modern pool automation. When paired with compatible control systems, you can:
Monitor heater status from anywhere
Receive performance alerts and diagnostics
Control pool temperature remotely
Optimize heater runtime for energy savings
Advanced Ignition & Performance Monitoring
An upgraded ignition control module continuously monitors flame strength and combustion performance, helping ensure:
Reliable startups
Cleaner combustion
Improved efficiency
Early fault detection before major issues occur
Optional Smart Heater Bypass (Major Energy Saver)
When the heater is not actively heating, the optional automatic bypass valve diverts water flow around the heat exchanger. This:
Reduces unnecessary heat exchanger wear
Improves overall system flow efficiency
Lowers pump workload
Can save up to 35% in annual operating costs* depending on runtime
User-Friendly Digital Display
Full-text interface (no codes to decipher)
On-screen diagnostics and status
Simple menu navigation
Faster troubleshooting for service techs and homeowners
Technical Specifications (Typical)
| Specification | Details |
|---|---|
| Fuel Type | Natural Gas or Propane |
| Heat Output Options | 200,000 / 250,000 / 333,000 / 400,000 BTU |
| Thermal Efficiency | Up to 84% |
| Heat Exchanger | Cupro-Nickel |
| Header Material | Polymer (corrosion resistant) |
| Ignition | Electronic with flame strength sensor |
| Venting | Category I |
| Plumbing | 2" PVC unions |
| Display | Full-text digital display |
| Automation Ready | Yes |
| Bypass Valve | Optional Smart Heater Bypass |
Tech Tips (From the Field)
Tip #1 — Use the Bypass
If you run a variable speed pump, the Smart Bypass dramatically improves system efficiency when heating is not required.
Tip #2 — Ideal for Salt Pools
Polymer headers and cupro-nickel exchanger make this heater highly resistant to salt and chemical corrosion.
Tip #3 — Tight Pad Friendly
The compact footprint makes this a favorite replacement for older heaters without replumbing the pad.
Tip #4 — Faster Diagnostics = Lower Service Cost
The full-text display helps identify issues quickly, reducing service time and guesswork.
Tip #5 — Pair with Automation
Maximum benefit comes when integrated with pool automation for alerts, monitoring, and remote control.
Commercial Sale Restriction
This item is restricted by the manufacturer for sale to pool professionals and service businesses only.
Is the sta-rite heater Max E Therm low NOx rated for Texas?
Reply
Yes the Sta Rite Max E Therm heaters are LoNox rated for Texas and California.
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Will a gas heater operate at the low speed of a dual speed motor?
Reply
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.
Reply
What is the Conversion from natural to propane?
Reply
Here is the Sta Rite MaxeTherm 400,000 BTU Natural Gas to Propane Conversion Kit.
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I am trying to hook the Max-E-Therm heater to a Jandy Aqualink controler. Need to know how to wire. Do I use 3 or 4 wire connection?
Reply
Hi Bart, The Max-E-Therm Owner's Manual does not indicate a 4 wire connection so it will be the 3 wire connection.
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I have ne of these for ten years and the exchanger is cracked well after ten years thats fine and I am sure it was a free at some point for this issue. Anyway, I want to purchase from your site as price is same everywhere join internet at $1999 but a local outfit out hear wants 3,250, are you kidding. I should be able to swap out the unit. And that is my question can you recommend an outfit out hear or is it simple. now mind ya I am quite capable and have hooked gas lines before, send email.
Reply
Hello Richard, We would recommend that the Max-E-Therm Heater 400000 BTU be installed by a licensed service technician. In the event you need to utilize the 1 year manufacturer's warranty, they may require receipt information of who it was installed by. We suggest you contact a local pool part/supply company that performs installations.
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The Most Helpful Review
2 0
(3 out of 5 stars) Good heater, BUT...
Reviewed By: Ronald R. from Clifton, VA ()
Pros: efficiency
Cons: durability
I purchased this heater from Inyopools approximately 5 years ago. It has been great, but I learned something this spring, do not buy this version, only purchase the Cupro Nickel version. The heat exchanger in this model is not long lasting. I just replaced this heater with a Raypak Professional B-R408A-EN-X.
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The Most Recent Reviews
1 0
(5 out of 5 stars) sta-rite pool heater
Reviewed By: Franz R. from Oakton, VA ()
this is my third pool heater and my last. Small and powerful, this heater is fantastic. all external parts are plastic covered, so it can't rust. It heats the spa in about 10 minutes to 90 degrees. I love it.
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1 1
(5 out of 5 stars) SR400NA Great Pool Heater
Reviewed By: William H. from Northern, CA ()
Pros: All pro
Cons: No cons
Great product, great service and friendly assistance.
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