Raypak Digital 406A
Good value for in-ground pools outside low NOx areas, provided it comes from an authorized dealer so the warranty holds.
Amazon $4,421.17$4,421.17
The Raypak Digital 406A is the better gas pool heater overall, rated 3.9 to 3.5. The Raypak Digital 406A leads on warranty and value. The Hayward H-Series H400FD wins on efficiency. The Raypak Digital 406A costs $677.83 less ($4,421.17 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 Raypak Digital 406A for warranty (2-year warranty vs 1-year warranty) and value ($11.08 per 1,000 BTU/h ($4,421.17, 399,000 BTU/h) vs $12.75 per 1,000 BTU/h ($5,099, 399,900 BTU/h)).
- Choose the Hayward H-Series H400FD for efficiency (84% thermal efficiency vs 82% thermal efficiency).
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 | Raypak Digital 406A | Hayward H-Series H400FD |
|---|---|---|
| Overall rating | 3.9/5 | 3.5/5 |
| Value 35% | 74 $11.08 per 1,000 BTU/h ($4,421.17, 399,000 BTU/h) | 56 $12.75 per 1,000 BTU/h ($5,099, 399,900 BTU/h) |
| Heating input 25% | 99 399,000 BTU/h | 100 399,900 BTU/h |
| Efficiency 20% | 33 82% thermal efficiency | 67 84% thermal efficiency |
| Warranty 20% | 50 2-year warranty | 0 1-year warranty |
Specifications
| Raypak Digital 406A | Hayward H-Series H400FD | |
|---|---|---|
| Heating | ||
| Gas input | 399,000 BTU/h | 399,900 BTU/h |
| Gas type | Natural gas or propane | Natural gas or propane |
| Thermal efficiency | 82% | 84% |
| Condensing | No | No |
| Low NOx | No | Yes |
| Heat exchanger | Copper | Cupro-nickel |
| Max water flow | 100 GPM | 125 GPM |
| Installation and controls | ||
| Ignition | Electronic | Electronic |
| Venting | Both | Both |
| Digital controls | Yes | Yes |
| Automation or app | Yes | Yes |
| Weight | - | 195 lb |
| Warranty | 2 years | 1 year |