Jabsco Par-Max HD4
#8 in 4 GPM and upFull review
A heavy-duty 4 GPM, 60 psi pump with a 3-year warranty at a fair price, for boats and RVs with two fixtures.
Amazon $165.60$165.60
The Jabsco Par-Max HD4 is the better RV water pump overall, rated 3.2 to 2.8. The Jabsco Par-Max HD4 leads on pressure and features. The Jabsco Par-Max HD4 costs $19.49 less ($165.60 vs $185.09).
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.
Johnson Pump Aqua Jet WPS 4.0
#12 in 4 GPM and upFull review
A marine pressure pump with a 3-year warranty, for boats where 41 psi is plenty. RV owners after a firmer shower should look at 55 psi pumps.
Amazon $185.09$185.09
Which should you buy?
- Choose the Jabsco Par-Max HD4 for pressure (60 psi shut-off vs 41 psi shut-off) and features (runs dry without damage, thermal protection vs none of the listed features).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 4 GPM and up RV water pump; a clear win is highlighted. How we rank explains each one.
| Factor weight | Jabsco Par-Max HD4 | Johnson Pump Aqua Jet WPS 4.0 |
|---|---|---|
| Overall rating | 3.2/5 | 2.8/5 |
| Value 25% | 34 $41.40 per GPM ($165.60, 4 GPM) | 27 $46.27 per GPM ($185.09, 4 GPM) |
| Flow 20% | 50 4 GPM rated open flow | 50 4 GPM rated open flow |
| Pressure 15% | 86 60 psi shut-off | 31 41 psi shut-off |
| Efficiency 10% | 28 0.35 GPM per amp (11.5 A max) | 50 maximum current draw not published (neutral score used) |
| Features 15% | 35 runs dry without damage, thermal protection | 0 none of the listed features |
| Warranty 15% | 67 3-year warranty | 67 3-year warranty |
Specifications
| Jabsco Par-Max HD4 | Johnson Pump Aqua Jet WPS 4.0 | |
|---|---|---|
| Performance | ||
| Rated open flow | 4 GPM | 4 GPM |
| Shut-off pressure | 60 psi | 41 psi |
| Max current draw | 11.5 A | - |
| Price per GPM | $41.40 | $46.27 |
| Self-priming lift | 8 ft | - |
| Features | ||
| Control | Pressure switch | Pressure switch |
| Diaphragm chambers | 4 | - |
| Runs dry | Yes | - |
| Thermal protection | Yes | - |
| Build | ||
| Weight | 5.6 lb | 4.5 lb |
| Warranty | 3 years | 3 years |