A low NOx, salt tolerant spa or small pool heater for owners who buy online and can live with a short warranty.
Amazon $3,699The Hayward H-Series H200FD rates 3.2 among under 250,000 BTU gas pool heaters; the Pentair MasterTemp 250 rates 2.7 among 250,000 BTU and up ones. The Pentair MasterTemp 250 costs $601 less ($3,098 vs $3,699).

A strong pick for in-ground pools already on Pentair automation, though online buyers get only a short warranty.
Amazon $3,098Prices 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.
Scores side by side
These two sit in different size classes (under 250,000 BTU and 250,000 BTU and up), and each is scored against the reference points for its own class, so a rating says how well each does among its own size peers. How we rank explains each factor.
| Factor weight | Hayward H-Series H200FD | Pentair MasterTemp 250 |
|---|---|---|
| Overall rating | 3.2/5 | 2.7/5 |
| Value 35% | 38 $18.50 per 1,000 BTU/h ($3,699, 199,900 BTU/h) | 60 $12.39 per 1,000 BTU/h ($3,098, 250,000 BTU/h) |
| Heating input 25% | 100 199,900 BTU/h | 0 250,000 BTU/h |
| Efficiency 20% | 50 83% thermal efficiency | 67 84% thermal efficiency |
| Warranty 20% | 0 1-year warranty | 0 1-year warranty |
Specifications
| Hayward H-Series H200FD | Pentair MasterTemp 250 | |
|---|---|---|
| Heating | ||
| Gas input | 199,900 BTU/h | 250,000 BTU/h |
| Gas type | Natural gas or propane | Natural gas or propane |
| Thermal efficiency | 83% | 84% |
| Condensing | No | No |
| Low NOx | Yes | Yes |
| Heat exchanger | Cupro-nickel | Copper |
| Max water flow | 125 GPM | 120 GPM |
| Installation and controls | ||
| Ignition | Electronic | Electronic |
| Venting | Both | Both |
| Digital controls | Yes | Yes |
| Automation or app | Yes | Yes |
| Weight | 140 lb | 133 lb |
| Warranty | 1 year | 1 year |