How To Diagnose Water Pump Problems Before Repairing Or Replacing RV Water Pumps
Okay, you've filled up the RV water tank and hit the switch to pump the last of the antifreeze out of the plumbing lines.
The only problem is... the RV water pump just keeps running and won’t shut off. The water flow is only a matter of a few drips at best.
Now what?
How To Diagnose A Water Pump Problem
The first step is to eliminate the obvious.
Are you absolutely sure there is a supply of water getting to the pump? Silly things like "you left the drain open when you thought you were filling the tank" have fooled more then one person into thinking their RV water pumps were bad.
If you disconnected the line from the tank to the water pump when you pumped RV antifreeze through the water lines last fall, has everything been reconnected correctly?
Is there a shut-off valve you forgot to open?
If your pump never made any noise at all when you hit the switch, lack of electricity may be a concern. Check the fuse in the 12-volt panel. If it’s good, check for power at the fuse with a volt meter or a test light.
Next check for power at the pump itself. If 12 volts are present at the pump, one last check should be made before you declare the pump bad: Check the ground for the pump motor. If the pump isn’t grounded, the presence of 12 volts will mean nothing. It takes a good ground to make the circuit.
Replacing An RV Water Pump
Once you have determined that yes, indeed, there is a water pump problem:
1. Drain the fresh water tank.
2. Disconnect the water lines. (But have a couple of towels handy, as there will still be a bit of water in the lines that may run out.)
3. Disconnect the electrical connections.4. Unbolt the RV water pump from its mounting
5. Bring the water pump itself out to the work bench.
All of this sounds very easy, and in theory it is. There may be one tiny problem: If your RV water pump is mounted like the one in my travel trailer, you may have to be a 60 lb skinny-as-a-rail contortionist to physically reach all the connections required to remove the RV water pump. There may be a removable access panel that will help you get at it, but most likely, it’s just going to be awkward and a bit of a pain.
How To Install A New RV Water Pump
There are 3 or 4 different brands of RV water pumps on the market.
Some have rebuild kits available, though most would be considered throw away items. With a wide selection of models available from $60 to about $150, it may be wise to just install a new pump and be done with it.
Installing a new RV water pump is as simple as remounting the pump, and reinstalling the water lines.
Be sure to use teflon tape on any pipe thread connections.
Pay attention to arrows on the water pump housing indicating which port is the "in" or "out". (They may be labeled as well.)
Carefully read the instructions supplied with the new pump and you’ll be up and running in no time.
Why Do RV Water Pumps Fail?
For the most part, 12-volt electric water pumps have proven to be quite reliable and long lasting.
The main reason for RV water pump failure (as with all RV water system components) is being left for the winter with water in the system. Extensive periods of storage in hot summer weather down south may also shorten the life span of an RV water pump.
Hi John, It sounds like the pump is becoming air locked or loosing its prime. Though (as is the case with my trailer) the pump should be able to draw water from a tank that is lower then the pump. If the pump is sucking air such as through a leaking fitting it may not be able to draw the water up. Otherwise the internal components of the pump may be warn and it isn't as effective as it once was about sucking water.
Here's a newbie question...
I recently bought a 1975 Mercedes Van which was transformed into a lovely camper by a very handy man from the south of the Netherlands. The water tank/pump was working just fine until the tank became empty and I had to refill it. In fact, the first time I filled it, the water didn't actually come out of the tap for a few hours after I had the pump on. However, this time, I left it for a couple days, and still nothing is coming out of the tap. Any suggestions? Everything seems to be working and nothing has changed since a few days ago when it was working fine.
Any suggestions greatly appreciated.
Bob, Those small 12v air compressors don't build up enough air fast enough. You'll need one with it's own air tank. Red lead to the red wire and black lead to the black wire or ground terminal. If you get it backwards it won't read the voltage, just swap the leads and you'll get a reading. No damage done. Can't help you on rehabing the pump, I've never had one apart. With 40 years owning RV's and 30 yrs as a heavy equipment mechanic just never had a problem with one that required taking it apart.
Curtis, I think I will purchase an air compressor and a blow out plug and at least blow out the water so our rv 28.5 foot Sunnybrook has dry lines. Your article is very convincing. My little question now is this: I had a friend that had an air compressor that was 12 volt and it worked off of the cigarette lighter plug in a vehicle. Would one of these do the trick? He used it for putting more air into tires. And finally I still want to do some more work on rehabilitating my Shurflo water pump (2nd one in 9 yrs) where on the pump do I place the red and black clips from my handy multimeter?.
Based on your other good comments from the website I would be willing to follow your instructions to rehab the pump or if it is not the pump pinpoint the problem of the pump not being able to take up water, even for a fee if permitted Curtis? I see my situation as a learning experience. Bob.
Bob, The key to my method of winterizing is to use an air compressor and blow enough air through the lines to push all the water through them. This article covers the process for you:
http://rv-roadtrips.thefuntimesguide.com/2008/10/winterizing_rv_water.php
Curtis I am responding to you mainly because you live in Minnesota, I do too. I noticed that upon testing my Shurflo 2088 water pump it would not pull or draw out water from a gal. plastic jug. So I contacted Shurflo on the web, they suggested that I buy a valve kit so I did. I will go to the lake shortly where we have our Sunnybrook 5th wheel and put the valve kit in. Test the pump to see if it draws water. We have the bypass system. Now Curtis if this does not work perhaps I could do as you say in one of your comments, here it is: I pour antifreeze down each drain, but I never put it in the water lines. I live in Northern Minnesota and over 30 years have never had a problem doing it this way and I've seen a lot of -20 degree weather. I plan on winterizing around Sept 20th. Using the bypass uses only 4 gals but I may have to do it your way, I do not mind using more antifreeze just so my rig gets properly winterized. I guess when you use the electric water pump it fills all the water lines (transparent lines going and coming into the hot water tank and the fresh water tank with pink antifreeze)? If I can not solve the 5 yr old water pump problem, perhaps besides considering your method, maybe I can just get a hand pump and then try to get the pump to work next spring.Or maybe just pour the antifreeze down the fresh water tank? Please advise and detail your procedure for me if possible. Bob from Duluth, MN Thanks loads.
Curtis thank you so much for the info. I located the water pump and looked at it I moved some wires and vola it started working. I will be a happy camper now. As far as the fridge it is now making a little noise so hopefully it will work also. I have it plugged into the house right now. If it works on the house electric then we will try the lp. Thanks for responding
Mary, the water pump is probably somewhere under the kitchen cabinets. There might be a removable panel hiding it. The refrigerator may be a plugged cooling unit. Though this is only a guess. One that old may have a lot of sediment built up in it. I say cooling unit because both LP and Elec are not working. If one or the other functions the cooling unit is fine. Replacing the cooling unit on an old fridge isn't worth the expense. Probably time for a new fridge.
I have a 1972 fleetwood travel trailer with no manual. Does anyone know where the water pump might be? The water pump was working fine then it quit. When we hit the switch there's nothing. Also the refrig. will not work on ac or lp. it was working 2 years ago which was the last time it was used. can someone help me please?
Chad, If the pump is building pressure and shutting off then I'm wondering if you have a shut off valve closed somewhere. Example would be a water heater bypass.
I have primed my pump, now when I hook it back up to the main water tank it will not pull the water up. The pump does turn off once preassurized so I do not want to go buy another pump. Please help me.
Bill, by runs normally and can't cut off power to the pump I'm reading that when pressure builds up it shuts off ok, but if your meaning the power switch on the wall won't shut it off the problem is likely in the switch on the wall. If the pump is running continually and won't shut off on it's own the pressure switch in the pump is bad or your leaking water someplace and t can't build up enough pressure to shut off.
My water pump runs normally but I cannot turn off the power to the pump. I think it may have gotten splashed with some water. Have tried drying the terminals but it will not power down with the switch. Any ideas?
thank you. Bill
br, there may be trash plugging the filter screen on the inlet to the pump. If not you may have a hole in the rubber diaphragm in the pump.
Pump runs but very little water reaches taps.
Solution?
Art, sounds likes it's time to consider a new pump.
My sureflow 2.8GPM pump will know work it does have 12volts to it and it tries to come on but stops turning. I disasembled it and can't find any thing wrong with it. I think it is a occilating type motor there is only room for the pump to turn aprox 3/8 of an inch in eather direction. it does and cant rotate becaus of the internal lugs in the housing. I think it might be the pump switch. any help.
Art
Richard, the best I can suggest is to fill your tank all the way. I don't really understand where this air your referring to is coming from. You might check the "City Water" port on the side of your RV as it includes a check valve that may be allowing air to get into the water line. I know I tend to be cautious myself, so I never leave my pump switch on unless I'm in the RV and awake. Things always seem to go south when your not there.
water pump is replaced and it is stell pumping air with water, the pump will not shout off, it is like it will not pick up water with out air, that is why I put a new own on, it ran all the time, I had 1/3 water left in my water tank, came home parked in the street, It was on angel, so all the water ran to one side, I got up the next day and the pump was runing all night, that is how it all started, I just don't know how to get the air out of the pump. thanks
Keep in mind, some pick-up lines in the fresh water tank don't pick-up at the bottom of the tank. In my Dutchmen 31K-DSL the pick-up line is on the right side of the trailer and attaches to the right side of the fresh water tank, about 1 & 1/2 inches from the bottom. I drained the fresh water, per the winterizing instructions and was not able to get the pump to pull any anti-freeze from the fresh water tank until:
1. The trailer was level or low on the right side.
2. Put 7 gallons of anti-freeze in the fresh water tank.
I could actually see the pink anti-freeze in the bottom of the tank.
7 gallons was enough to get the lines filled, but just barely. It was still sucking some air and the pump never really stopped. 8 or 9 gallons probably would have been optimum.
Russ, Your on the right track, the only other suggestion would be if your water tank is mounted at a higher level then the pump by hooking the pump back to the water tank and filling with water you will be flooding the pump assuring the best possible priming which will let you confirm if the pump is bad or not. I would think the pump should be able to suck the antifreeze out of the jug as most RV's have the water tank mounted underneath requiring the pumps to be self priming.
I am trying to winterize my travel trailer. I have always run a hose from the inlet side of the pump to the gallon of antifreeze, turned on the pump and pumped the antifreeze thru the lines with no issues. Today, the pump would not pull the antifreeze thru the lines. The pump is on but not pumbing. Wondering if I could have lost prime or if I have a bad pump. How would I re-prime the pump. Water hose won't fit..... and tried pouring water thru the 3/8" hose, but no luck.
Bruce, There are two possible problems. First, is there a filter of any kind on the inlet side. If it's plugged up you might get that reaction. Though the more likely cause would be a damaged diaphragm in the pump allowing air to get into it. I guess its a question of are you getting more water then air, or mostly air. If it's mostly air I think your pump may be going south.
Curtis,
I have a question, what would cause my system to spit air between spurts of water. It's not just the typical pulsation but it actually spits air/water when getting water from the fresh water tank. Any suggestions?
Hi Russ, If you want to pump antifreeze through the lines you will have to find the water pump and disconnect the waterline coming from the tank. Then place a hose from the antifreeze bottle to the pump and you can pump it through. Personally I've never used this method myself. I hook up a low pressure air line (5 psi)to the city water inlet and pressurize the system with air. Opening one faucet at a time until all the water is pumped out. I pour antifreeze down each drain, but I never put it in the water lines. I live in Northern Minnesota and over 30 years have never had a problem doing it this way and I've seen a lot of -20 degree weather.
Got a question about winterizing, I have a 1991 Terry Tauras and am wondering how I go about pumping antifreeze through the system. I am not sure where the water pump is and then how I would go about pumping antifreeze from the antifreeze bottle through the system. What we have done in the past was take my outside water line that ran to the trailer and put antifreeze in it and then pushed it through via an air compressor, this is very time consuming and I have heard that you can somehow just stick the water pump hose in the bottle and pump it through that way, but I am not sure how to do that. Any help would be appreciated.
Thanks
Russ