Water Pump Questions

Question: I have not used my fresh water pump since purchasing my 1993 in Granville Motorhome last June 2011. I filled up the water tank and followed the instructions. I hear the pump when I turn the switch on, but no water flows through the lines.

When I am hooked up to city water there is no problem at all. What am I doing wrong? I have to empty that tank to winterize.

Without getting into anything that may be specific to your particular motorhome, here are some general comments on the subject. You should be able to drain your fresh water tank without the pump — it will just take longer. You need to trace the fresh water system to identify the drain.

On our motorhome the fresh water tank and water pump is visible through my plumbing bay. Our drain is easily accessed and by a few turns of a valve drains the tank. We have never used our water pump to drain the fresh water tank. When we drain the tank we attach a water hose to the drain and route it back to the sewer connection – it takes about 4 hours to drain our 100 gallon fresh water tank.

As for your water pump operation, if it were our rig, there are a few things we would try before taking it to a repair facility. We would check for a bypass of the water pump, kinked or pinched waterlines, put in a new water filter (if equipped), and make sure that the water pump is actually functioning.

Checking your water lines:

  • Disconnect your RV from your city water supply
  • Turn on the water pump switch and leave it on
  • Open any faucet
  • Locate your water pump by the sound
  • Turn off your water pump every few minutes to prevent overheating the pump
  • Look at the water lines going into and out of the water pump – you are looking for kicked or pinched lines or a valve that bypasses the water pump
  • Locate the line that comes out of the water tank and feeds into the water pump – make sure that it is not pinched or kinked
  • Turn off your water pump
  • If the lines look good then located your water filter

Water filter:

  • If you have one replace it with a new filter. Make sure to turn off your water pump first or you will get wet
  • If your filter is fine or you do not have one then you will have to go back to your water pump

Water Pump test:

  • To test the water pump you will need a bucket of water and 2 short pieces of flexible water lines and a few clamps
  • Fill the bucket with water
  • Examine which line come into the water pump and which goes towards the motorhome – when you are sure mark them accordingly so you can reconnect them properly
  • Disconnect your RV from your city water supply
  • Turn off the water pump open all your faucets and let them drain, leave the faucets open
  • Remove the pre marked water line from the pump inlet
  • Attach one of the flexible hoses to the water pump inlet and tighten the clamp – make sure that the hose fits the water pump inlet, then take the other end of the hose you just attached to the pump and put it into a full bucket of water
  • Remove the pre-marked water line that connects to the water pump outlet
  • Attach the other flexible hose to the water pump outlet, tighten the clamp and point it at the ground
  • Finally, have someone turn on the water pump and observe if water comes out:

    * If the water pump makes a sound but no water comes out or if the steam of water is weak then the pump is defective or it could have a plugged up filter/screen. Depending on the pump model and manufacturer it my be possible to rebuild the pump.

    * If water comes out but and the stream is strong, then it would seem that the water pump is okay and something else is causing the lack of water flow through the lines. At this point, we can’t suggest any further trouble shooting ideas, and suggest that you seek some professional assistance.

We hope this helps.

Comments for Water Pump

May 04, 2016 Check your check valve
by: Jose

Our best guess is that you have a bad check valve in your fresh water supply line. You can do one of two things to fix this:
One, replace the city water supply port or
Two, replace the check valve that resides behind the city water supply port. Either should fix the problem. Another solution is to cap off the city water supply port while using the water pump.

May 04, 2016 water problem
by: Anonymous

I got the trailer ready for camping and filled the water tank and turned on the pump – and it’s pumping it back out the city spout. Can you help me find out whats wrong?

Mar 11, 2014 Question on use of water pump
by: ron

Question: I am new to RV world. I am told when hooked up with city water I should not use my water pump. Yet if I do not use water pump, there is no pressure and water stops coming our of shower, faucet etc…Is it mandatory to use water pump when hooked up to city water?

Answer: The simple answer is no, you do not need to have the water pump on. When you have the water pump on it draws water from your on board fresh water tank and feeds it to the fresh water system. However, while connected to city water you can leave the pump on since it will not cause any harm.

Now back to your problem. First make sure that you have water at the external fresh water supply and that the supply is on fully, then make sure that your hose is clear of obstructions and is not kinked.

Second make sure that you do not have any water shutoff valve turned to the off position. We have a shutoff located just before the water goes into the RV and I can’t tell you how many times I’ve left it in the off position.

After you have checked all the obvious stuff it is time to check the fresh water connection to the RV. If the only way to get water out to the faucets while connected to city water is with the water pump on then you will need to check your fresh/city water access. Behind the female garden hose’s threaded connection for the city water supply you will find a check valve. To get at the check valve you may have to remove the surrounding hatch. This check valve, if malfunctioning, will prevent city water from flowing into the RV. This valve is the most likely cause for you having to have the water pump on to get water out to the faucets.

If you have a water pressure regulator it may also cause a similar problem if it goes bad or is incorrectly adjusted (if it is an adjustable type). Regards, Jose and Jill


Water Pump May be Broken

by Robert (Harrisburg PA)

Question: We have a 2006 Jayco Jay Feather travel trailer, and the water pump does not work. Can you tell me what to replace it with?

Answer: First make sure that the water pump is actually not working. Check to make sure you have power (12-volt) to the water pump.

If the water pump is actually inoperative, and you have access to the water pump, try to find the label on the existing unit and replace it with the same brand and type.

You can also contact the RV manufacturer and ask them what brand and model water pump they suggest as a replacement. They may also be able to offer some tips for doing the repair.

Comments for Water Pump May be Broken

Sep 29, 2012 RE water pump replace
by: Anonymous

Once you confirm it is actually the pump as the issue, then after removal look at the label. There should be a gph rating. Just try to match the rating or model# as close as possible.

Noise can also be an issue as the pump cycles. You may want to opt for a better pump that is less noisy. Shurflo or Flojet make just about all RV water pumps. Camping World has them all.


Water Pump

by Cynthia (Black Hawk, Colorado)

Question: Where do you find the water pump on a 1999 Catalina Sport by Coachman?

Answer: We suggest you contact the manufacturer or your owners manuals for diagrams. You can turn on the water pump and listen and try to find it that way, but if that doesn’t work, contact Coachman.

Water Pump for Fleetwood Jamboree

by Orlin (Peoria, AZ)

Question: I left the water pump on while traveling and now it won’t run. Where should I start in determining the issue?

Answer: We have always traveled with our water pump on as long was we have water in the fresh water tank. A few things come to mind: a burned out water pump fuse, a broken wire to the water pump, a bad water pump switch or associated wiring or a bad water pump.

If you traveled with the pump on and no fresh water in the fresh water tank, then there would be no water pressure and the pump would run continuously.

So you could have burned out the pump or caused the fuse associated with power to the pump to overload and burn out. If it is not the fuse then make sure that you have power at the pump, switch and associated wiring before you replace the water pump with a new one.

Other input welcome.

Water Pump Switch

Question: I left the RV water pump switch ‘ON’ while driving down the road. Will that damage the pump? The switch does not light anymore – is there a fix?

Answer: We have always traveled with our water pump on with no problems. The only time the water pump is activated is when it senses a drop in water pressure, like when a faucet is open or a toilet is flushed or if there is a leak in the fresh water system. So driving with the water pump on should not present any problems under normal circumstances.

If you traveled with the pump on and no fresh water in the fresh water tank, then there would be no water pressure. In that case, the pump would run continuously, trying to pressurize the system, until one of the following happens: the water pump fuse blows, the water pump burns out or the water pump switch burns out.

If the preceding was not cause of the problem, then another problem could be a bad connection somewhere between the power source and the pump (this also includes the water pump switch).

The fix is to determine if the water pump still works, regardless that the light on the water pump switch does not light. If it does not work, then look for a blown water pump fuse. If it is not the fuse then make sure that you have power at the pump, switch and associated wiring before you replace the water pump with a new one.

Comments for Water Pump Switch

Jan 14, 2016 water pump location?
by: Anonymous

I have a 1987 31′ Pace Arrow and the water pump is not working and I need to know the location of the water switch center.

Jul 13, 2015 water pump wiring
by: Anonymous

Since your pump works it seems it was connected properly. Conventional wiring calls for the red pump wire to be connected to the positive terminal (+ battery) and the other wire whatever color to the negative (- battery or ground).

Jul 12, 2015 water pump wiring
by: Anonymous

My pump was not working I checked on it and the wires are not connected , pump has red wire and black camper has orange and white. I connected the red and orange and black and white. The pump worked but is this the correct way ?