Troubleshooting: Electric Water Pump

[Kya]

I have an 08' FWC Eagle. It has the standard 12 gallon non-pressureized water tank. The issue I'm having is that the pump works fine when the tank is full, and half full. However, when there is only about 1/3 water remaining (anywhere from 4 gallons and less), the water pump stops working. It still makes noise and I can see water traveling through the hose, but it is not reaching all the way to the sink. The unit also has a manual hand pump at the faucet, but even that does not work under the same scenario.

I can see water entering the pump from the tank (clear tube on the right), and flowing through the pump, up the clear tube on the left. But it only reaches about 2/3 of the way up.

Is this normal operating proceedure for when a water tank level gets lower? I don't think so, but I have only owned the camper since late April. I did a brief kind of half assed search and did not find anything similar.

Any input would be great.

 

[tanglefoot]

The pump does have to work harder when the tank gets low as there isn't as much gravity pressure at the tank outlet.

I was having the same problem when using the little centrifugal pump that was in the camper when I got it. I replaced it with a little diaphragm (I love sounding that out) pump and it does much better. It even has an auto pressure-switch...I love it.

You could trace along the tubing to make sure there aren't any kinks or restrictions that are limiting flow. That vinyl tubing likes to twist and kink on me.

I really liked the pictures of your San Juan tour.

Eric

 

[pods8]

I think you issue is the pump is laid out wrong, in the picture the suction is coming from above, I'm guessing that means the tubing is going up and over the dividing wall between the compartments? That means the pump is having to suck the water over the top and it's burning up it's ability to generate pressure by doing so. That pump is meant for a "flooded prime" which means its really not rated to suck water up hill much.

The fact it works fine with a fuller tank sort of confirms this in my mind. You should redo the suction to go through that dividing wall in a straight run to the tank suction and also mount the pump head lower down. Or move the pump into the other compartment. Or change the style of pump.

 

[MakersTeleMark]

I think you issue is the pump is laid out wrong, in the picture the suction is coming from above, I'm guessing that means the tubing is going up and over the dividing wall between the compartments? That means the pump is having to suck the water over the top and it's burning up it's ability to generate pressure by doing so. That pump is meant for a "flooded prime" which means its really not rated to suck water up hill much.

The fact it works fine with a fuller tank sort of confirms this in my mind. You should redo the suction to go through that dividing wall in a straight run to the tank suction and also mount the pump head lower down. Or move the pump into the other compartment. Or change the style of pump.

This. Your plumbing is routed too vertical. Also, instal a small in-line check valve.

http://www.amazon.com/SHURflo-340-001-In-Line-Check-Valve/dp/B000BGJWF2

What you can do in the meantime, although not glamorous, is to suck on your hand pump faucet to get the water to start flowing.

 

[Stan@FourWheel]

I can't see exactly what is happening the the upper cabniet from the pictures, but do you think you have room to cut a little slack out of the clear plastic water hose and move the water pump up higher on that side wall ?

Just a thought.


Feel free to call Terry in our service dept if you like.

He might be able to give you some helpful tips & tricks.


FWC SERVICE

800-242-1442

ASK FOR TERRY



Thanks


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[Kya]

Excellent. Thanks you guys! I think the easiest would be to move the pump up the wall (easiest = within my skill level). I think I will try that first, then look into the other suggestions if I don't see an improvement. I love this forum.

 

[MakersTeleMark]

I'd be glad to help out. I just installed running water in my camper a couple of months ago. You want to watch out for where you place the pump in relation to the bottom of the tank.

 

[pods8]

Excellent. Thanks you guys! I think the easiest would be to move the pump up the wall (easiest = within my skill level). I think I will try that first, then look into the other suggestions if I don't see an improvement. I love this forum.

Unfortunately I'm going to have to contradict stan on this one. It doesn't do anything to address the fact the pump is having to suck the water out of the tank. Going over that wall is really hurting you, but in general the higher the pump head is off the bottom of the tank the worse it's going to perform for you with this type of pump (flooded inlet design, mini centrifugal pump).

 

[Stan@FourWheel]

Pods could be right.

We installed the water pumps like your for years and years without any problems.

Having the water pump low (like the pictures you posted) were never a problem in the past. So moving it "up" might not help.

You could just have a water pump that is failing and doesn't have the "pumping power" it used to.

The other thing I thought of when I first read your post ... << maybe the water tank is empty and the customers doesn't know it ? >>

If you are looking at the small water monitor on the front of the cabinets and it is only showing one light (1/3 full) there is a chance that the water tank is empty. If this is the case the water pump would be sucking mostly air and not pumping water out the faucet. The water monitor panel is just a general indicator of how much water is in the tank, not a totally accurate reading.

Just call our service shop.

Terry and Chicali have a good common sense approach and might be able to shead some light on the subject for you.

Thanks !





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[pods8]

Pods could be right.

We installed the water pumps like your for years and years without any problems.

Having the water pump low (like the pictures you posted) were never a problem in the past. So moving it "up" might not help.

You could just have a water pump that is failing and doesn't have the "pumping power" it used to.

Manufacturer on that pump recommends 4" of suction lift max and ideally a flooded inlet. Pumps may have been able to eak out a bit more to perform over time for you (or folks never ran their tanks low) I suppose. Pump might now just be falling in line with its original design and can't take the extra suction distance it's not designed for.

In reality the pump is much better suited for the way pvstoy set it up (I've copied the same setup in my FWC). You get the suction lower/closer to the tank outlet and have the added bonus of being able to drain the lines backwards to the tank when draining it for the winter. http://www.wanderthewest.com/forum/index.php?/topic/1260/page__view__findpost__p__12975

 

[Stan@FourWheel]

The older Eagle Models usually had a hand pump at the sink, as well as the electric water pump if the customer ordered it.

So you could "pump" the hand pump a few times to get water flowing and that would prime the electric water pump.

My guess is that the tank is almost empty when this is happening, or the pump is going bad.

Pods suggestions are very good.


But most customers don't want to open up the cabinets to relocate the water line.






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[Prybry]

That's a pump that shouldn't run dry...

My guess would be that the pump is wore out... since that is not a "run dry" type of pump it is likely in need of a rebuild or replacement.

One other thing to check is the feed line... if it was replaced with a thin wall rather than reinforced hose it might be sucking the hose flat... this would also go for the hand pump as well. When the water level is high it doesn't have to suck as hard due to natural head pressure. Once it drops low enough the draw becomes high enough to suck the line flat or nearly so.

Either way the pump is probably seen better days...:snorkel:

 

[Kya]

No way the water tank is empty. When this first happened, that's what I thought. But when I got home I pretty much filled a 5 gallon water bucket from the tank drain valve on the outside of the camper. That was when I knew something was not right. Not even the hand pump will work when in the scenario explained in my original post. Besides my electric monitor only reeds 3/3 or 2/3. So I haven't been able to go by that monitor anyway. Any way to fix that too?

Maybe just upgrading the pump to a new or slightly different style might be the best/quickest solution. The previous owner used the camper and water pump a lot he admitted. I haven't had time do anything with it yet.

 

[pods8]

One other thing to check is the feed line... if it was replaced with a thin wall rather than reinforced hose it might be sucking the hose flat...

That mini centrifugal pump isn't going to suck those lines flat (looks like basic PVC tubing in the picture). A more robust pump that could pull more suction (and thus wouldn't require a flooded prime) could do something like that though if the line got plugged.

Not even the hand pump will work when in the scenario explained in my original post.

This statement throws be for a curve ball though (assuming your hand pump isn't wore out and works at other times). It should be rated to pull enough suction... Off the top of my head I'm not coming up with much that would work in one scenario but not the other except the remote chance someone reworked the suction connection to a higher point on the tank but I find that doubtful. Hmmm.

 

[wannaby]

Hi I may be off base here but do you have a outside connection that you can attatch a city water line to also if so I think that line needs to be capped of when not in use.