Since we launched our adventure in late May, we have been dry camping.  Each week we haul 15 miles to a rest area to dump and fill.  Since we are disconnected, we have to rely on the water pump to provide pressure. 

Prior to leaving Denver, we camped a couple nights without water hookup to see if everything worked.  It did.  I did wake up early one morning to hear the water pump running.  Odd.  It seemed that the pump had lost pressure at some point. 

We have replaced the kitchen and bath faucets with residential faucets.  We have replaced the shower faucet with a new RV shower faucet.  We have also replaced the shower head and hose.  These replacements were because we didn't like what was there and we suspected that since they were 3 years old, they may be on their way out.

The pump seemed to come on and just low rumble kind of run without generating any pressure.  We called the dealer a couple times for troubleshooting advice, but without acutally seeing the trailer they aren't much help.  This problem has gotten progressively worse through the summer.  It progressed to losing pressure when the tank indicated 2/3 full and we turn the pump on and off as we need it.  This last week a fuse blew (it was the incorrect fuse).  After we replaced it, the pump fails to generate any pressure at all.  If it does, it won't shut off when the system reaches pressure and the pressure release valve is triggered.  We have ordered a replacement pump as we suspect that the pressure sensor may be shot.  The pump is a Shurflo Extreme 5.7.

When we turn on the water, particularely hot, there is lots of air in the lines.  It seems that by turning on the shower hot water we can help blow out the air and get pressure again.   There doesn't seem to be nearly the problem with air in the lines with the cold water.  We ahve a pre-filter and a sediment filter inline and have checked both of these for tightness.  When we installed the new showered faucet we installed it upside down so that the hose came out of the top.  Tonight we are going to flip it over and see if  that helps any.  However, we were having this probelm before replacing the shower faucet.

Do any of you have some advice on what to look for or have you had this issue yourself?  I think we have two issues - pump and air in the lines - and I'm not sure if they are related or now.

I will check back with you on Monday when I again have internet access.

Thanks so much for your thoughts on this.

I don't know why but when I use our fresh water tank the pump will ocasionally loose prime for no aparent reason. I usually have to open a couple faucets and purge the air then it's ok again. It always bothers me because on my old SunnyBrook the one time that happened I had a leak in the water lines it took a while to discover. I suspect air in the lines is the problem but can't figure out why.

When we switch back and forth from city water to using just the on board water, we will get air in the lines. I just open all faucets, cold and hot, for a minute or so to bleed the water (use a plastic bowl to catch the water to use to clean dishes). This gets rid of the air and then the pump can function properly. Air in the lines will cause the pump to act up. Another common problem is the check valve on the inlet for city water sometimes sticks open. This will cause the pump to run. If it's leaking just a little, the pump my cycle on and off as the pressure bleeds off through the check valve. This is a one way valve. You can clean it but usually a few pushes will clear whatever is keeping it open. once in a while the valve will need to be replaced. Another common problem is the pump will leak internally. Pressure will bleed off into the lines. This will also cause low water pressure and the pump to stay on or cycle. The pump needs to be replaced or rebuilt. Id say your pump is shot. I think this is what you have been experiencing. I couldn't tell from your post if you have already installed a new pump and are still having a problem or have ordered a pump and was just checking to see if there are other possible causes for your problem. If you haven't installed the new pump, I'm betting the new pump will fix everything. If you have installed the pump and are still having problems, the check valve would be suspect. Or there's a leak some where and it's not showing up. You'll need to follow all lines and check each connection. Our bathroom sink faucet hot line will leak and the water dribbles down the backside of the line so I can't see it. It follows the line down into my basement storage area and drips on the carpet in a spot that isn't readily seen. After a few days I finally begin to see signs of moisture and realize the connection is leaking again. Maybe you have a bigger hidden area where water is collecting and it evaporates before you see any signs of a leak.

When you first put water in an empty tank and then pump up the plumbing system you should be able to bleed off the air in the system at that point. You may have to open the faucet two or three times to get it all out but that should be it. Occasionally you might get a sputter of air but nothing like you described. If air gets in the system after that then there is an opening somewhere in the system. If there is an opening in the system there will be water leaking out. If you thoroughly check the system for leaks, on the ground below the trailer--in all storage compartments under all sinks around the water heater, around the pump make sure all drain caps are on tightly stuff like that and you don't find any wet spots then the pump head is probably shot and won't hold a prime. Some pumps, if the motor is still good (it runs) you can order and replace just the pump head. It generally is almost as expensive as replacing the whole pump. You may want to look at the check valve it should keep the water from running back thru the pump into the holding tank causing a vacuum and sucking air into the system. In my opinion it would pretty much have to be a combination of problems to be anything other than your pump. Like Bear II said I'm betting its the pump.

Good Luck
Flyone

All I know is that the sur-flo 5.7 is not the greatest pump. You will be able to find lots of threads on its short comings. I'm on my third since 2007 (all warranty) but I think next time I'll get a 4008 (replacement for 2088).

Thank you all for the feedback. I think the new pump will fix the problem, but I we are still going to check the system for leaks as suggested. We would bleed the lines and sometimes it would take about a minute to get the air out and the pump running again. igotjam confirms a surprise that we had when we studied the labeling on the pump. It was manufactured in Feb 2009. We got the new pump installed on Friday morning and oh what a difference. The old pump was very noisy which we thought was normal. This pump is much quieter and currently seems to be holding it's prime and we have much greater water pressure. One thing we did find when we removed the old pump was that there was a broken O ring on the connector between the pump and hose. We are following the recommendation on the manufacturer's instructions and turn the pump off when we leave or go to bed. Hopefully this will help extend the life of this pump.

One thing I do to avoid air in the plumbing is to let the water fill the hose before I get it in the rig.  This way, I never get air bubles.  Just one of my tricks and it works great!  If one day I get lots of air, I will know that something is not normal.

It's always a good idea to flush out the hose and see that clear water comes from the pedestal before hooking up to your rig. For some reason or other it's not uncommon for some sediment to come out when you first turn it on. It's also a good idea to put a sediment filter on the hose before it comes in the rig. they are only about $15 and last a long time.

Curiosity question since I'm not an RV owner yet. If at a campground, why not just keep the tanks filled and run off those vice running off of city water? Wouldn't this alleviate any pressure differences?

Gary.....After 3 pumps in 3 years, using city water vs a pump that wears out is more cost effective though what you suggest will work. In my case the 5.7 puts out 65psi which is too much for my plumbing to take. (it springs leaks when using the pump so I try to minimize its use) I use city water with a regulator set at 35psi most of the time.

The other "problem" is the pump is not exactly quiet. Much depends on how they are mounted, but they all make noise to some extent. Not really a problem when the neighbors are not parked right next door (as in Q-Town LTVA), but in an RV park type setting it would be annoying to anyone parked close.

Also, if you end up with an almost full tank when you want to leave, you have to carry another 3-400 pounds around, or wait for it all to drain. It's really much simpler to just hook up to their water.

Thanks for the education. Ya learn something new every day. Yet another item to place in the research spreadsheet. Once again, thanks.