How To Prime An RV Water Pump (5 Step Guide)

Whether you have just installed a new water pump in your RV, or taking your RV out of storage from the winter, you will most likely have to prime that RV water pump. If you do it the correct way then it’s a really simple and fast process, here is everything you need to know on how to prime an RV water pump (the right way).

As you are about to see, this is easily done in a few simple steps. We’re also going to provide you with some RV water pump troubleshooting issues in the event that it won’t prime. 

how to prime an RV water pump

How To Prime An RV Water Pump

Priming an RV water pump only takes 5 easy steps, so let’s get to it.

Step 1: Fill The Freshwater Tank & Check The Valves

Using your water gauge to pay close attention to the water level, start by filling the freshwater tank with fresh water. At this time, you also want to check to see that all of the valves are in the right position.

For instance, this means that the winterization valve needs to be closed, while the fill tank valve needs to be in the normal position.

Step 2: Turn On The Tap

You now want to turn on one single cold water tap in the RV. Make sure that you only turn on one tap. All other taps should be turned off.

Step 3: Activate The Water Pump

On the water pump, you should see some kind of monitor or display panel, complete with an on and off switch. However, if you cannot find the on-off switch, you will need to consult the owner’s manual of your RV to find it. 

Either way, you now want to turn that switch into the on position to turn the pump on. Generally speaking, if you have a decent RV, at this point, the pump should actually prime itself. 

It’s going to take water out of the freshwater tank, send it through the pump, and push it out of the tap that you have open.

Step 4: Let The Pump Run

When you turn the pump on, if everything is functioning properly, you should notice water and air sputtering out of the tap that you have on. 

Water can take quite a while to make its way through the water lines and to the faucet, so don’t fret if it takes a few seconds or even a minute. 

When water does start flowing through the open faucet, let it continue flowing until it stops sputtering. you want only water to be coming out, not air.

Step 5: Open All Faucets

You now need to repeat this air purging process for every water line in the RV. This is going to include all of your water faucets. Therefore, open up all of the faucets one at a time. 

When one of them has only water flowing through and does not have any air sputtering out, close it, and then open up the next one, until all faucets have been taken care of in this manner.

Troubleshooting An RV Water Pump That Won’t Prime

In case your RV water pump won’t prime, there are a few troubleshooting steps for you to follow, as listed below.
Follow the troubleshooting steps in the order listed below;

  1. If your RV water pump is not pumping, the first thing to do is to check the freshwater tank. Although quite unlikely, you might have forgotten to fill the freshwater tank. If the tank has no water in it, then the pump obviously can’t pump any water.
  1. The next step here is to check all of the water lines. For instance, make sure that everything is plugged into the proper outlets. It does happen that you could plug your water hose into the black tank flush inlet. You then want to inspect all of the lines that are connected to the water pump, starting with the main line leading to the pump. You are going to look for any signs of leakage, damage, or loose connections. Make sure that everything is in proper order and connected.
  1. You will now want to check all of the valves. Make sure that all of the valves are in the proper position. For instance, the water intake and outlet valve should be open, while the winterization valves should be closed.
  1. Your water pump requires electricity to function, which means that it uses a fuse. If your pump is not making any sound at all, it could be a blown fuse. Therefore, try inspecting and changing the fuse. It happens to run on a breaker panel, see if the breaker has been tripped. If this does not work, and your pump still doesn’t make a sound, it may have other electronic issues or issues with the motor that you will unfortunately not be able to fix on your own.
  1. You then want to check the inlet strainer to see that it is clean and not clogged with any debris. These pump strainers tend to be made out of fine mesh and they can clog rather quickly. You also want to see if the lines have any kinks in them.
  1. What you then need to try doing is manually priming the pump. Most pumps are self-priming, however, they might not always work, especially if they’ve been sitting around for a long time. Different pumps require different manual priming methods, so you will need to check your owner’s manual.
  1. If all else fails, you are going to need to get a professional to take care of the issue for you.

How Long Does It Take To Prime An RV Water Pump?

If you follow the process above properly, it should not take you longer than five or 10 minutes at the very most to prime an RV water pump.

All you really have to do is turn on the pump, turn a faucet on, and wait until water flows out without any air sputter. Realistically, a few minutes is all you should need here.

Madeline Cooper
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