Pentair MasterTemp 400
A strong pick for in-ground pools already on Pentair automation, though online buyers get only a short warranty.
Amazon $4,079$4,079
The Pentair MasterTemp 400 is the better gas pool heater overall, rated 3.9 to 3.5. The Pentair MasterTemp 400 leads on value. The Pentair MasterTemp 400 costs $1,020 less ($4,079 vs $5,099).
Hayward H-Series H400FD
A low NOx, salt tolerant in-ground pool heater for owners who buy online and can live with a short warranty.
Amazon $5,099$5,099
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Pentair MasterTemp 400 for value ($10.20 per 1,000 BTU/h ($4,079, 400,000 BTU/h) vs $12.75 per 1,000 BTU/h ($5,099, 399,900 BTU/h)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 250,000 BTU and up gas pool heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Pentair MasterTemp 400 | Hayward H-Series H400FD |
|---|---|---|
| Overall rating | 3.9/5 | 3.5/5 |
| Value 35% | 84 $10.20 per 1,000 BTU/h ($4,079, 400,000 BTU/h) | 56 $12.75 per 1,000 BTU/h ($5,099, 399,900 BTU/h) |
| Heating input 25% | 100 400,000 BTU/h | 100 399,900 BTU/h |
| Efficiency 20% | 67 84% thermal efficiency | 67 84% thermal efficiency |
| Warranty 20% | 0 1-year warranty | 0 1-year warranty |
Specifications
| Pentair MasterTemp 400 | Hayward H-Series H400FD | |
|---|---|---|
| Heating | ||
| Gas input | 400,000 BTU/h | 399,900 BTU/h |
| Gas type | Natural gas or propane | Natural gas or propane |
| Thermal efficiency | 84% | 84% |
| Condensing | No | No |
| Low NOx | Yes | Yes |
| Heat exchanger | Copper | Cupro-nickel |
| Max water flow | 120 GPM | 125 GPM |
| Installation and controls | ||
| Ignition | Electronic | Electronic |
| Venting | Both | Both |
| Digital controls | Yes | Yes |
| Automation or app | Yes | Yes |
| Weight | 136 lb | 195 lb |
| Warranty | 1 year | 1 year |