Jabsco Par-Max 3 25 psi
#8 in Under 4 GPMFull review
A low-pressure pump for boats and gravity-style systems where gentle 25 psi flow is wanted. Most RVs want a 45 to 55 psi pump instead.
Amazon $121.48$121.48
3 GPM25 psi5.2 A
2.0/5
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.
- 2 GPMFlow
- 30 psiShut-off
- 3.5 AMax draw
- Pressure switchControl
Check price at Amazon$114.80
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Draws just 3.5 A, the lowest here
- Small enough for a boat cabin or van locker
- Runs dry without damage
Cons
- 30 psi shut-off makes for a weak shower
- No bypass, so it cycles at low flow
- Pentair publishes no warranty term for it
The Shurflo Aqua King II family
Every Shurflo Aqua King II model we rank, smallest first. Ratings compare each against its own flow.
| Model | Flow | Rating | Price |
|---|---|---|---|
| Shurflo Aqua King II Junior 2.0 (this one) | 2 GPM | 2.0/5 | $114.80 |
| Shurflo Aqua King II Premium 4.0 | 4 GPM | 2.8/5 | $236.33 |
| Shurflo Aqua King II Supreme 5.0 | 5 GPM | 3.1/5 | $359.09 |
How it scores
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its flow. How we rank explains each one.
Specifications
| Model number | 4128-110-E04 |
|---|---|
| Performance | |
| Rated open flow | 2 GPM |
| Shut-off pressure | 30 psi |
| Max current draw | 3.5 A |
| Price per GPM | $57.40 |
| Features | |
| Control | Pressure switch |
| Internal bypass | No |
| Runs dry | Yes |
Alternatives in this flow
Shurflo Revolution 4028 2.3 GPM
#9 in Under 4 GPMFull review
A low-draw 2.3 GPM pump for a small camper or van with one fixture in use at a time. Larger rigs get more water per dollar from a 3 GPM pump.
Amazon $120.10$120.10
2.3 GPM50 psi5 A
Jabsco Par-Max HD3
#10 in Under 4 GPMFull review
A heavy-duty 3 GPM marine pump with a 3-year warranty. It costs more than lighter pumps with higher pressure.
Amazon $166.06$166.06
3 GPM40 psi8 A
Compare
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