Seaflo 42 Series 3.0 GPM 55 psi
#1 in Under 4 GPMFull review
A strong-value 3 GPM replacement: 55 psi, a bypass and a 4-year warranty for about half the price of the name-brand equivalent.
Amazon $59.32$59.32
The Seaflo 42 Series 3.0 GPM 55 psi is the better RV water pump overall, rated 3.7 to 2.0. The Seaflo 42 Series 3.0 GPM 55 psi leads on value, pressure and flow. The Shurflo Aqua King II Junior 2.0 wins on efficiency. The Seaflo 42 Series 3.0 GPM 55 psi costs $55.48 less ($59.32 vs $114.80).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Shurflo Aqua King II Junior 2.0
#11 in Under 4 GPMFull review
A small, low-draw pump for a single galley tap on a boat or van. Its 2 GPM at 30 psi is too little for an RV with a shower.
Amazon $114.80$114.80
Which should you buy?
- Choose the Seaflo 42 Series 3.0 GPM 55 psi for value ($19.77 per GPM ($59.32, 3 GPM) vs $57.40 per GPM ($114.80, 2 GPM)), pressure (55 psi shut-off vs 30 psi shut-off) and flow (3 GPM rated open flow vs 2 GPM rated open flow).
- Choose the Shurflo Aqua King II Junior 2.0 for efficiency (0.57 GPM per amp (3.5 A max) vs 0.43 GPM per amp (7 A max)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every under 4 GPM RV water pump; a clear win is highlighted. How we rank explains each one.
| Factor weight | Seaflo 42 Series 3.0 GPM 55 psi | Shurflo Aqua King II Junior 2.0 |
|---|---|---|
| Overall rating | 3.7/5 | 2.0/5 |
| Value 25% | 82 $19.77 per GPM ($59.32, 3 GPM) | 13 $57.40 per GPM ($114.80, 2 GPM) |
| Flow 20% | 25 3 GPM rated open flow | 0 2 GPM rated open flow |
| Pressure 15% | 71 55 psi shut-off | 0 30 psi shut-off |
| Efficiency 10% | 51 0.43 GPM per amp (7 A max) | 92 0.57 GPM per amp (3.5 A max) |
| Features 15% | 40 internal bypass, runs dry without damage | 20 runs dry without damage |
| Warranty 15% | 100 4-year warranty | 0 warranty not published, scored as none |
Specifications
| Seaflo 42 Series 3.0 GPM 55 psi | Shurflo Aqua King II Junior 2.0 | |
|---|---|---|
| Performance | ||
| Rated open flow | 3 GPM | 2 GPM |
| Shut-off pressure | 55 psi | 30 psi |
| Max current draw | 7 A | 3.5 A |
| Price per GPM | $19.77 | $57.40 |
| Self-priming lift | 6 ft | - |
| Features | ||
| Control | Pressure switch | Pressure switch |
| Internal bypass | Yes | No |
| Runs dry | Yes | Yes |
| Build | ||
| Warranty | 4 years | - |