For a long time, we have noticed that the water pump doesn't supply any water when the water in the tank gets down to about 1/4 full. It makes funny noises (thunk, thunk, thunk -ish) and might spurt a few drops here and there, at most. We are level, so that isn't an issue. As a result, we have simply gotten in the habit of making sure we have plenty of water over 1/4 full, when necessary.
But why haul all the extra weight around? And why join a LD forum if not to ask questions? Has anyone experienced this? Is there any solution, or is it just something we have to live with?
If that is your original pump it is likely time to replace it. The LD factory has used different pumps over the years, some notoriously bad. I nursed mine when it started acting up just like your pump, but it eventually failed, luckily while parked at home. I called several places near me and they all talked about modifying the LD set up from what the factory originally did in 2007. I became wary of modifications and splices so I called Vince at the factory and set an appointment for him to install a new pump and inspect my roof condition. He gave me a clean bill of health in regards to the roof and expertly installed a new pump. He remarked that my original pump (variable speed) was a bad design and I might have set a record in having it so long before replacement.
Gary
I know that some of us actually carry a replacement water pump in the rig....
topcat, I have a 2003 TK; the original water pump was a Whisper King 2.0 gpm. The current water pump (in my rig) is also a Whisper King; this was the spare pump. The old Whisper King was discontinued some time ago; the current suggested replacement is a 4008 (or a 4048; read the specs); that one is now my spare when the Whisper King fails. It is definitely advisable to carry a spare water pump.
The pump that Gary referred to is probably a Shurflo 5.7; it was, to say the least, "trouble-plagued". Check out the information at this link and consider replacing your water pump.
SHURFLO® Fresh Water Pumps (http://shurflo.com/rv-products/rv-pumps/rv-fresh-water-pumps)
TC,
By what means are you guaging your 1/4 full fresh water tank? Any chance that it is closer to empty than the guage leads you to believe?
Kent
By the way, we carry a spare too.
Hi Tom. The noise you report when low doesn't sound like I would expect. I wonder if something could be floating around in your tank, and bumping up against the outlet, in the tank, going to the pump. I agree with Kent that if you are relying on the standard gauges, they are really un-reliable.
When you can't get anymore water from the pump, does a quarter of the tank still come out of the drain? I'm not familiar with your floorplan. Can you look at the tank near the tank outlet to the pump? RonB
I'm measuring the water level by peering in with a flashlight, so the level is accurate.
That said, my pump is original which makes it 15+ years old. I can't read it precisely, but it definitely says both WhisperKing and ShurFlo. Whether it is near dead or not, getting a replacement to have on hand sounds like the thing to do, so my wife will call LD (I can't hear on the phone) and make sure we get the right model. It is very accessible on the MB and replacing it looks like a breeze.
Thanks everyone, for the quick and sensible responses!
The Whisper King is obsolete and is not available anymore.
Older LDs were equipped with fixtures that used a 2.0 GPM pump, the replacement is the Shurflo Revolution 4028.
Amazon.com: SHURFLO (4028-100-E54 12V 2.3 GPM Water Pump: Automotive (https://www.amazon.com/SHURFLO-4028-100-E54-12V-Water-Pump/dp/B00FEBZBZE?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B00FEBZBZE)
Later model LDs need a bigger, 3.0 GPM pump, the common replacement for the 2003 and later LDs is the Shurflo Revolution 4008.
Amazon.com: SHURFLO 4008-101-E65 3.0 Revolution Water Pump: Automotive (https://www.amazon.com/SHURFLO-4008-101-E65-Revolution-Water-Pump/dp/B002XM5G70/ref=sr_1_2?ie=UTF8&qid=1533605797&sr=8-2&keywords=SHURFLO+4008-101-E65+3.0+Revolution+Water+Pump)
Larry
Hmmm. Just a thought - on my MB, the tank outlet is at floor level. From there, the hose rises to the strainer, about 14" up or so. From the strainer, the line drops down to the pump.
This means the pump is pulling the water over a rise, and the amount of rise increases as the tank level drops. If you had a crack or a leaking connection at or near the strainer with a setup like mine, that part of the line is not under pressure, so water leakage might not happen, but under a vacuum to pull water up from the tank, perhaps air might be getting into the line? Air in these pumps can cause a lot of noise.
Caution - this is nothing more than an unsupported idea.
Ken F in WY
Gary, it looks like I may have the record, then. I still have the original pump in my '06 30' TB. What pump did Vince replace yours with? The Revolution 4008?
thx,
Mike S.
Larry - Thanks for the links. I've ordered a replacement / backup.
Ken - I checked. The line from the tank to the pump is straight out of the bottom to the pump with no rise. So it really is funny that the pump acts up the way it does, but still works fine if there is enough water in the tank. Given the age of the pump, I'll probably go ahead and replace it when the new one arrives. It will be interesting to see if it behaves differently.
Mike - mine is still "working" after 15 years. We're just about to head out for a couple days in the wilderness. We'll see if it holds up for two more days!
Mike S,
Yes, I believe it was the 4008. I recall Vince saying that it was the current pump that they are using...………..
Gary
Ken, I checked out those strainers when we thought we might have to replace our pump. Surflow discourages them - I think they were useful for the older pumps but not required at all for the new pumps.
Tom, you can do all sorts of playing - like disconnect the tubing from your tank to your existing pump and connect it to your new pump and confirm the new pump works to the bottom of the tank (using a pipe from the pump outlet to a bucket or sink (or holding the pump over a bucket or sink - outlet pointed down).
If you do not have flexible hoses (eg have the old grey pipes) this is the time to put those in at least where you are touching. Shurflo sells a set - the difference between these and what you can get at the hardware store is the internal diameter is larger (more flow with less pressure). A little higher cost but the higher internal diameter was worth it for me (it didn't make the pump quieter for us).
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For a long time, we have noticed that the water pump doesn't supply any water when the water in the tank gets down to about 1/4 full. It makes funny noises (thunk, thunk, thunk -ish) and might spurt a few drops here and there, at most. We are level, so that isn't an issue.
In general, as long as there is no air in the intake, the pump should not care what the tank water level is. I.e., you probably have air leaking in. Check the exit fitting-to-tank connection, tubing connections, and if you have an older rig with grey polybutylene tubing and fittings, they are highly suspect - look for cracks in the fittings.
Steve
Steve,
I was thinking that with more water in the tank there would be more pressure and with less water that be less pressure going into the pump. Not a lot of pressure difference but maybe with a failing pump enough to make a difference.
But I was taking a guess with this.
If air was being sucked in at low water tank level, would it not be also sucked in with high tank level?
Tom, a good idea to check for leaks while you are mucking with things. I like to do the touch with fingers method checking for tiny bits of water but others have said they put paper towels down and then come back later looking for evidence water got on it.
We had hard water crystals in our pump (from hard tap water - common in AZ and many western states). That caused a low flow (compared to using city water hookup) at all times - no matter how much water was in the tank. Cleaning the pump brought it back to great working order.
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"...with more water in the tank there would be more pressure and with less water that be less pressure..."
It is the pump itself that provides the pressure, from suction side to output, everything prior is gravity feed. ;)
A weak pump might have trouble priming, but once primed, only leak down due to air intrusion should kill the prime. Where air leaks in is likely to allow water out, too.
Steve
Hi. The pressure at the pump inlet rises about .44 psi. per foot of water in the tank. A defective inlet valve might let the pump appear to be OK, until the level got lower. The reported noise makes me think that the output valve isn't opening, and the backflow preventer valve IS working properly. Water isn't compressible, hence the banging. A new pump sounds like the cure for this.
My first showers in the new motorhome led me to get a different shower head, with smaller holes, to help my original WhisperKing keep up the pressure with a slower flow rate. That pump is still working. The shower head uses less water per minute than the shower head that came from LD. When needed I'll probably get the ShurFlo 4048. RonB
The new pump hasn't arrived, but when it does, I'll check all the fittings and hoses when installing and report the results. It may be a while before I respond, since we have a trip planned and I'm not sure when the pump will arrive. Thanks to everyone for all the suggestions.
My tank has five gallons of water in it when the pump starts sucking air so I figure that's my reserve water. I can drain five gallons into a container after I'm empty at the pump.
Reporting back after installing a new pump (Shurflo 4008) in my 2003 MB, replacing the original, 15 year old pump.
First, I checked the old strainer, fittings and hoses. They all looked shipshape and after much dithering, I decided not to replace them. The new pump has the same footprint as the old, but the in- and out- takes are just about an inch higher than on the old pump. As a result, I had to reposition the pump so the strainer was clear of the sink trap. This wasn't a big deal since there was a fair amount of room to work with. I'd rate the degree of difficulty for the pump replacement about 5 on a scale of 10. It would have been more like a 3 if it were easier to reach into the cabinet.
The results:
- The new pump is much, much quieter. This hints that maybe a bearing was going bad in the old pump.
- The pump simply needs the water tank filled enough to cover the fitting from the tank to the pump. Sawyer says 5 gallons, and that seems about right. The intake on the new pump is much higher than that, but the water in the tank does NOT need to be that high!
- And it is still a mystery as to exactly why the old pump would not pump when the tank got down to 1/4 full, since all the fittings, strainer, etc. are OK and everything works fine with the new pump.
Thanks again to all who responded. I feel a lot better having replaced the pump and NOT encountered additional issues (something that always happens on my home improvement projects!).
I will probably instal the water pump I have been carrying around for 3 years tomorrow. I guess I need to drain the water heater and water tank to avoid to much spilled water?
I put new rubber diaphragm things in almost 4 years ago when I noticed a small leak. Those parts were over $30. I paid around $60 for the whole pump. I don’t know if parts are still available for the current one, which likely is the original from 2003. I figure if it is likely that old it may be worth the small extra cost to replace the whole thing.
Reminds me of a problem I had with my 1996 Dodge van fuel pump. Worked fine until gas tank dropped to something below a half tanks. Then backfired a lot. It may have been destroyed by time I got to first gas 30 miles away. I did not figure our that keeping over half a tank of gas would help till later. Anyway by time I got home 200 miles I needed an expensive intake manifold gasket replacement.
I don’t know how much water might be left when my pump can no longer move it. Less than the 5 gallons that makes the display go from 1/3 to empty. I tested that once and was able to dump 5 gallons from the water tank right at the point the monitor switched to “empty”
Jay, you'll definitely need to empty everything or you'll have a mess. I was hoping I wouldn't need to drain the hw, but the tank is too high relative to the pump (at least on our MB), so it has to be drained.
I will probably instal the water pump I have been carrying around for 3 years tomorrow. I guess I need to drain the water heater and water tank to avoid to much spilled water?
No reason to drain water you can use Hose Pinch Off Pliers (https://www.amazon.com/GearWrench-145-Hose-Pinch-Pliers/dp/B000O3NACS)
It’s not a bad idea to occasionally drain the water tank and so easy to do with the drain valve.
Larry
"I was hoping I wouldn't need to drain the hw, ... so it has to be drained."
Hmmm! Guess the different floor plans are not the same in this regard. I have replaced my water pump three times and not once have I considered draining the hot water tank. ::)
I think there is supposed to be a check valve to prevent the water heater from draining water back into the cold water plumbing, but they may not always work. With my rigs stiff water pipes and advanced age, I would rather just empty the tanks. I wouldn't use that clamp gizmo on anything but soft vinyl or newer rubber hose. RonB.
I got the pump installed (Shurflow 4008). It seams to pulse a lot when running only cold water and low flow. I am wondering if this will cause shower temperature to fluctuate on low flow. It runs smoother with hot or half hot so I am thinking it will be ok and will soon try it. I tried adjusting the pressure switch a 1/4 turn in either direction but that did not make much difference. Perhaps a break in thing? The instructions warn against adjusting the bypass if you are not a pro with proper tools :(
"It seams to pulse a lot when running only cold water and low flow."
Mine does that also and it has been adjusted by the master, Vince, himself. If you know how difficult it is to work on the water pump in a 30' IB you will not wonder that he was somewhat displeased, yet he got the job done, much to his credit. ::)
Give it a reasonable trial period and I think you will be able to live with it! ;)
Good point. I should have thought of that since that is what our washing machine repair guy would do. Anyway, be sure to have two since you'll have to pinch both the in and the out hoses if you drain neither tank.
"It seams to pulse a lot when running only cold water and low flow."
Mine does that also and it has been adjusted by the master, Vince, himself. If you know how difficult it is to work on the water pump in a 30' IB you will not wonder that he was somewhat displeased, yet he got the job done, much to his credit. ::)
Give it a reasonable trial period and I think you will be able to live with it! ;)
Well until I find a new home I will have to live with it! I hope it is at least as good as the model 2093 Whisper King it replaced. That one has worked well for almost four years since I put new rubber diaphragm in. I was able to stop the pump from cycling with low flow in the shower on the old one by increasing the pressure that turns it off. This minimizes the inevitable temperature fluctuations that go with reducing the flow.
I tried adjusting the pressure switch a 1/4 turn in either direction but that did not make much difference. Perhaps a break in thing? The instructions warn against adjusting the bypass if you are not a pro with proper tools :(
It's a bit of witchcraft to adjust the by-pass and pressure switches. Finding the sweet spot can take a bit of time and a few adjustments.
Has anyone tried an accumulator? Not needed but they say it increases pump life.. I don’t care much but some folks may like less cycling (noise). I do like the idea of smoother flow. Hmmm... maybe I would like longer but less frequent pumping.
One is in our RV, put in likely by the original owner. It is an 89 and with pumps at that time it made a difference. The original pump was replaced at some point but the accumulator was left in place.
I researched when we thought we might need a new pump (just needed cleaning) and the concensus seemed to be it is not needed with current pumps.
One thing - it does take up a chunk of space. Ours is a cylinder about a foot across and 1 1/2' long.
At some point we will test with and without it but right now I don't know if it makes any difference.
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Has anyone tried an accumulator? Not needed but they say it increases pump life.. I don’t care much but some folks may like less cycling (noise). I do like the idea of smoother flow. Hmmm... maybe I would like longer but less frequent pumping.
The old Whisper King pumps benefited from an accumulator.
The Factory literature for the newer pumps, such as the 4008, tell not to use accumulators .
So, having an old accumulator on hand, I had to try it with the new pump. The accumulator disrupts the pump's pressure switch and regulator. There is no improvement.
The newer pumps need fiddling with the two control screws to run smoothly.
Larry
I adjusted my bypass switch as well as adjusting the pressure switch some more yesterday and I’ve got it to stay on even with a pretty low flow. The flow is also smoother than it was.