No water flow when dry camping

[Chargerzuk]

I just bought a 1999 Coachman Mirada and we took it dry camping and we had no water flow. So when we came back I hooked up to city water hose and the flow was fine. So I bought a direct replacement Shur flow water pump and installed it and flow is still a dribble. I have checked for in line water filter and I cant find one. I have cleaned all the ariators in the fixtures. I am puzzled. I have good pressure when hooked up to city water so I know my water lines aren't blocked. I even turned on the pump for a minute while hooked up to city water lines and it increased the flow. What would you guys suggest I check next?

[Chargerzuk]

I am going to try it with the fill valve closed like Pkunk suggested. I don't think there is any line blockage because when I hook it up to city water I have good flow and then if I turn on the pump for a minute it increases the flow. If the valve doesn't work I am going to attach a hose to the pump to see if it is pumping with good pressure and if it doesn't work at the pump then the line must be blocked or a valve closed.

[chainegang]

A partially blocked aerator or other blocking sources in the lines AFTER the pump would cause the pump to cycle on and off as the preasure reached maximum and then fell below minimum as water is drawn. If the flow is unusually slow AND with little preasure and constantly running pump, then my vote would be a partial blockage BEFORE the pump's preasure head. Sediment or some other foreign matter is impeading a full water flow to the pump. Some units have a screen at the discharge point inside the water tank that with age gets plugged. Hard to believe that a 2010 model would already need maintenance, but it's possible. A white film (scum) does build up in a water tank even with regular disinfecting. That film can work it's way to the discharge point and cause the symtom you describe. The scum floats and or clings to the side of the tank. When you draw down the water in the tank to empty it or to use it all up for use, the scum collects and is drawn to the screen by the pumps action. The screen is part of the fitting that is the same diameter as the hole that penetrates the tank and is easily removed for cleaning and or inspection. The other possibilty with the same sympton would be a partially blocked filter on the water pump, if there is one. Then as others have suggested, foreign matter inside the pump, but that for me is the least llikely culprit given the symtom you describe.

[pkunk]

On your Mirada, the water control panel in the rear compartment can be a bit confusing. If you stare at the pictogram long enough it will be evident. The valve orientation for 'use' has only one valve open. It is just the opposite from 'fill'. Every thing else should be closed which on that panel is vertical on the oval knobs. If you don't solve it, PM me and I'll take a pic for you.

[westernrvparkow]

Two simple tests. One, loosen the line from the intake on the pump and see if water flows out. If it doesn't the line from the tank to the pump is plugged, either at a filter or at a fitting. If it flows, hook it back up and disconnect the outlet line from the pump and connect a hose to it and see if it pumps water out. If it does, you have an obstruction between the pump line and where it connects to the house plumbing. If it doesn't, the problem is at the pump and the most likely problem since you changed pumps is the connection at the intake. If it does not seal up airtight, the pump will suck air and not pump efficiently. This problem happened on my diesel pusher. The shop that winterized it, cross-threaded the connector. It didn't leak water, but didn't create a complete suction so the pump wouldn't pump water. Simple fix was to put in a new washer, make sure it threaded correctly and tightened up. Worked like a charm.

[enblethen]

Yes, turn off the "fill" valve.

[Chargerzuk]

Thanks for the imput I will check the valves. The water tank was full it is under the bed right next to the water pump so I could see it full as I changed the pump. I had both valves open the one that says "fill" and the one that says "use". Should I have closed one to use the onboard pump? I tried closing and opening the valves when camping and it made no difference in water flow. Also I made sure all the winterizing valves were closed. I had a toyhauler trailer before I sold to buy this motorhome but it had a separate fill valve for city water and for filling the water tank so I am still learning how to work this thing.

[riven1950]

As folks suggested check all your valves / switches first. If not that then it could be the problem I just had last week:

My problem was two fold. 1- filter from tank to pump needed cleaning. 2- The fitting on the tank ( outlet to pump ) itself was clogged somehow inside the tank...must be a screen on the inside. Mine was glued not screwed into the tank, so rather than risk messing the tank up I kept back flushing the connection with a water hose. Also put in clorox, filled tank, and let it sit for a couple of hours, back flushed some more and now the system works as it should.

Also, you can hook a hose to the pump outlet. If it pumps out ok you know the problem is after the pump. If you still get a dribble your problem is between the tank and pump.

[WyoTraveler]

Also, each manufacturer is a little different. My MH has a valve in the wet bay for selection of city water, tank water, winterizing, normal etc. Make sure the valve is in the correct position for what you want to do.

[Artum_Snowbird]

I think enblethen nailed it.. On mine, there is a valve that I have to open to allow pressurized water from the city to fill the tank as opposed to allowing the water into the taps directly. If I forget to close that valve, the pump runs like crazy, but not much happens as it is just recirculating.

[enblethen]

How do you fill the fresh water tank? Do you have a valve that says "fill" tank? If you have such a valve it could be in the wrong position. If your fresh water tanks fills by gravity fill only this is not your problem.
Check between the pump and the fresh water tank for water. Disconnect line from tank at pump and see how much water you get. Does your pump have a screen filter on the tank side? is it clean/

[Old-Biscuit]

Basic RV water system......



Pump discharge and city water connect and feed the same plumbing system so it everything works on city water than everything works using pump......provided

You have fresh water in the tank for pump to suck up
The pump is turned on and all air is removed from system by opening faucets while pump is running
You wait long enough for water heater tank to get filled (6 to 10 gallons depending on size of WH)
The pump inlet strainer is not clogged
There are no air leaks on pump suction side
The 'winterizing kit' valve (if equipped with one) on suction side of pump is closed
The pump actually runs.......no blown 12V DC fuse

And it being a MH.........do you have valves/switches on a water panel that have to be set to 'normal' or 'pump' vs having the valves/switches set to 'fill' or 'city water' etc.??


So.......
Go out to your trailer.
Turn pump on and see if you have water flow. IF not check the above listed items.

ON EDIT:
Save that pump you replaced.....you will probably be able to use it as a spare or as a water transfer pump or as a anti-freeze pump.
It was probably still working OK........you just need to find YOUR issue.

[mbopp]

Any chance the valves on the pump intake are set in the winterizing position?

[sodajerk]

Mine has a little filter in the tank where the pump input is. It unscrews from the tank. A little scrub with a toothbrush cleans it up. Look for obstructions in the line from the tank to the pump.

[2oldman]

Yes, start with the basics. Do you have water in the tank?