Guide to the Best 12v DC Water Pump for Your RV

If you need a steady supply of water, a pump is a necessity. This is true whether you’re watering your plants, or whether you’re trying to take a shower. For home applications on a water line, the pump is a large commercial one, run by the water company. For homes with a well system, this is a 230 or 120-volt well pump. For an RV, this means a 12-volt DC water pump. A 12-volt pump will run on your RV’s built-in 12-volt power system, so it won’t require any adapters.

That said, not all 12-volt pumps are equally well-engineered. For instance, some are self-priming while others are not. Similarly, others can pump water to higher levels, or with higher pressure. As a result, it’s important to do your research before you go out and buy any old 12-volt pump.

We’re about to review three of the best 12-volt DC water pumps on today’s market. We’ll begin with the Shurflo 2088-554-144 Fresh Water Pump. This is a thermally-protected pump with a three-chamber diaphragm design. Next, we’ll check out the Seaflo Water Diaphragm Self Priming Pump. This pump allows for high vertical applications, and is also suitable for marine use. Finally, we’ll examine the Lippert Components 12V Flow Max Water Pump. This pump provides an impressive 50 PSI, which is more in line with normal residential water pressure. Which one is the best for your needs? To find out, we’ll have to dig a little deeper, and consider all of their benefits and potential drawbacks. Only then can we render a fair verdict. Let’s get started!

Features to Look for in a Quality RV Pump

Beyond the basics, like quality construction, vibration resistance, and a quiet motor, what else should you look for? The first is to make sure the pump actually runs on electrical power. In particular, you should avoid gas-powered or solar-powered pumps. These are great solutions for an off-grid hunting cabin. But they’re not suitable for an RV, which is what we’re looking at today.

Standard RV pumps run on 12 volts of power, which is the voltage of an overall RV power system. For this reason, it’s essential that an electrical RV pump runs on 12 volts. If you find a 110 or 120-volt pump you really like, don’t buy it. It’s not going to work in your RV. Those pumps are designed for residential use, and generally provide higher pressure. This is needed for residential purposes, particularly where water has to be pumped up to the second floor. A 12-volt pump, on the other hand, will be easy to install and replace your existing RV pump.

So, you need a 12-volt electrical pump. But this is a common specification, and you’ll find a dozen or more at any RV supply store. How do you narrow that down to a more reasonable number? There are plenty of things to look for, but three factors are far more important than others. These are: gallons per minute (GPM), pressure (PSI), and amperage (motor power).

GPM is a measurement of how much water flows through the pipe. For example, if a pump puts out 2.5 GPM, it will provide 2 ½ gallons of water every minute. Most showers and faucets will work just fine around 2 GPM. Keep in mind, though, that you might want to use multiple taps at once. With a low-pressure pump, this can lead to a slow in the flow.

Water pressure is measured in pounds per square inch, or PSI. Residential water systems vary widely, anywhere from 30 to 80 PSI. RV water systems are more standardized, and are designed to handle 40 to 60 PSI. More pressure is good, but more than 60 is very, very bad since it can damage your RV’s plumbing. Steer clear of pumps that advertise high pressure ratings for your RV. It’s not worth the marginally stronger flow.

Amperage measures the strength of the motor itself. Most RV water pumps are designed to draw as little power as possible, since this is a limited resource. However, some high-volume pumps can draw as much as 15 amps. This isn’t nearly as much as a residential pump, but it’s something you should be aware of.

How to Replace a 12-Volt Water Pump

Modern RVs come with their own water pumps, so if you’re buying one, it’s either a refit or a replacement. Either way, you’re going to have to roll up your sleeves and get to work. Alternatively, you could hire a qualified RV technician, but they charge a lot, and the replacement is fairly easy. 12-volt DC pumps have a standardized design, so there shouldn’t be a lot of finagling involved.

The first step is to turn off your water supply valve and disconnect your RV’s power system. This means shutting off all of your breakers to ensure all the wires are dead. Now that you’re dry and there’s no current, find your RV’s water pump. Removal should be fairly straightforward. The input and output hoses attach with a pair of hose clamps, which will need to be loosened. Thankfully, a simple screwdriver or adjustable wrench — depending on the screws — will make quick work of this task. Once the hoses are disconnected, unscrew the pump from its mount.

The final step in the removal is to cut the old wires. Make sure to remember which wires went to which connection. The best way to do this is to snap a picture, so you don’t get anything mixed up. Once that’s done, you simply lift out the old pump, set the new one in place, and reverse the steps. It’s a good idea to inspect the old hose clamps for rust, and replace them if necessary. They only cost a few pennies, and an old, failed hose clamp can really ruin your day. Once the new pump is installed, restore your power, turn the water back on, and test it out. Assuming everything is connected properly, you should be good to go!

Shurflo 2088-554-144 Fresh Water Pump

The Shurflo 2088-554-144 Fresh Water Pump is designed to run as quietly as possible. Its standout feature is its large, stainless steel base with fat rubber shock-absorbing bushings. When the pump is screwed down, these bushings will compress, providing excellent vibration absorption. As a result, noise transfer is kept to a minimum, and remains in the pump compartment, where it belongs. The overall size of the Shurflo pump is 10.3 inches long, 6 inches high, and 4.7 inches thick. It weighs 5.1 pounds, surprisingly light for the size and power.

The internal pump is a positive displacement three-chamber design. We’re not going to dig too deeply into the technical aspects of this pump, but suffice it to say it’s effective. You get 3.5GPM of flow at 45 PSI. The motor uses a permanent magnet to provide a continuous flow of water, and is thermally protected to prevent damage. Like the other pumps on our list, the Shurflo can run on any 12-volt power supply. That said, it’s designed to be wired in, not to use a 12-volt plug. If you want to run it off of a power station, you’re going to need an adapter.

The Shurflo pump has a built-in check valve, which prevents reverse flow. This means it’s safe to use with a plumbed toilet, since no tank water will return through the valve. Not only that, but it’s available in a one-pack, a two-pack, or a four-pack. This isn’t helpful for RVs, but it has its own applications. For instance, if you want to supply an off-grid house, you can run four pumps simultaneously.

Seaflo Water Diaphragm Self Priming Pump

The Seaflo Water Diaphragm Self Priming Pump has a similar diaphragm design to the Shurflo pump. This means it’s capable of continuous flow, which is what you want from an RV pump. The overall size of the unit is a bit smaller, though. It’s a bit shorter, at 7.84 inches, and the 5-inch height is less, as well, although the thickness is basically the same. At 4.62 pounds, the weight is very similar, and it has a standard mounting configuration. After the Shurflo pump’s sturdy base, the plastic mounting base was a bit disappointing. It won’t absorb vibration quite as well as the Shurflo.

That said, the Seaflo has some distinct advantages. For one thing, it’s self-priming, and can support a 6-foot vertical run. It can also run dry without getting damaged, which is a huge concern when you’re priming. The water capacity is 3 GPM, which is quite reasonable, and the pressure is a respectable 45 PSI.

The main attraction of the Seaflo pump is its ability to support marine applications. To this end, the kit includes a pair of ½-inch barbed hose adapters, as well as a mesh inlet strainer. Simply install these adapters and you’re ready to hook into your boat. This is all protected by a four-year manufacturer’s warranty, one of the best in the business. If there are any failures during that time period, you’ll receive a refund or a replacement.

Lippert Components 12V Flow Max Water Pump

The Lippert Components 12V Flow Max Water Pump is designed for maximum pressure. It outputs at an impressive 50 PSI, while maintaining 3 GPM of water flow. This means more powerful showers that feel like you’re in a full-sized house. Not only that, but it’s capable of self-priming, and can run dry without burning out. This makes it suitable for non-RV applications where water supply may be intermittent.

Despite all this, the size of the Flow Max isn’t overly large. It measures 10.5 inches long, six inches tall, and 5.5 inches thick. At 4.5 pounds, it’s reasonably lightweight and easy to install. To be fair, the plastic base doesn’t do the best job of absorbing vibration. There are no rubber bushings, but it’s still better than metal-on-metal.

The motor draws 9.5 amps, so it’s reasonably powerful without drawing an excessive load. It’s also corrosion-resistant, so a little leakage isn’t the end of the world. Finally, the pump itself is rated to sustain multiple freeze-thaw cycles. Obviously, you shouldn’t intentionally let the pump freeze with water inside. But accidents happen. When they do, it’s good to know your housing hasn’t been cracked.

Final Verdict

Clearly, any one of these pumps would make a suitable replacement for most RVs. That said, there are still some important differences to take into consideration. For instance, we started out by reviewing the Shurflo 2088-554-144 Fresh Water Pump. This pump’s main advantage is its high rate of water delivery. At 3.5 GPM, you can run two faucets simultaneously without any significant drop in pressure. Even with this large delivery capacity, the Shurflo pump runs quietly. Rubber bushings prevent it from transferring a lot of vibration to the rest of your vehicle. It’s also available in a two or four-pack if you want to run multiple pumps simultaneously.

The Seaflo Water Diaphragm Self Priming Pump, as its name implies, is a solid choice for marine applications. Because it can self-prime over a six-foot vertical, it’s great for boats and other similar uses. The barbed connection adapters are easy to attach, as is the mesh inlet strainer. Admittedly, the Seaflo is a bit louder than the Shurflo. But if you need self-priming performance and a marine rating, it’s a great choice. Not only that, but the four-year manufacturer’s warranty provides an excellent added value.

The Lippert Components 12V Flow Max Water Pump has two things that set it apart from the others. First, it supplies water at 50 PSI. This gives it more of a residential feel, despite the average 3.0 GPM flow rate. Second, it’s resistant to freezing and thawing. This makes it suitable for extreme environments, where accidental freezing is a concern. Combine that with a powerful, self-priming 9.5-amp motor, and you’ve got an excellent pump.