Water pump runs continuously unless water heater is on

[bickp]

Hi all, I have a situation that I cannot figure out. Trailer is at home and I am checking out systems before a trip that is about 30 days out. About a month ago I sanitized fresh water tank and faucets then flushed and filled fw tank.

When I turned on the pump it just kept running. Inlet cap was tight, water was swirling in the clear view screen filter, no water leaks apparent below the pump area or incoming water lines that I can see. No water leaks around the outside.

The weird part: I turned on the water heater using propane, not electric. Water heater fires up and runs for 3 or 4 minutes.

Go back in the trailer and turn on the water pump and it does not run. Go to the kitchen sink, turn on hot water and pump runs exactly as expected and turns off as soon as I turn off the spicket. Same in the bathroom. In the bathroom I feel the hot water and it's getting hot as you would expect. In both kitchen and bath I run pure hot, then turn it off and pump stops. Then run pure cold and a mix of hot cold. All with same result, pump stops as soon as the spicket is closed, it works perfectly.

This was last months scenario, which matches exactly what happened today. Last month I walked away shaking my head because I could not figure it out and had more pressing matters to deal with outside of the trailer.

As we get closer to trip time, I walked through the process again today with the exact same result.

Why would the system (the pump) work exactly as it should when the water heater is on, and pump continuously when it is not?

[uncle_bob]

Hi

You have air in your lines. That air heats up (expands) with the water heater on. The expansion raises the pressure. Higher pressure shuts off the pump. Best guess would be air in the hot water heater tank.

Spend some time on city water. Run each line for several minutes. Exercise all the faucets and valves. Do them one at a time. Eventually you will find one that spurts a bunch of air.

After all the playing with city water, go back to the fresh water tank. Dump any air in that line the same way.

Bob

[GCinSC2]

If you can get a simple water pressure test gauge and connect to the trailer exterior hose spigot (assumption 1 is that you have one) and add the pressure to your list of observation inputs. Home centers have them just a gauge and fitting combined.

Assumption 2 is that the pump is not building pressure easily to tell pressure switch OK turn off now. Hot water tank is bolstering system pressure fooling the pressure switch.

Did you notice the declared assumptions?

Gary

[bickp]

Originally Posted by uncle_bob

Hi

You have air in your lines. That air heats up (expands) with the water heater on. The expansion raises the pressure. Higher pressure shuts off the pump. Best guess would be air in the hot water heater tank.

Spend some time on city water. Run each line for several minutes. Exercise all the faucets and valves. Do them one at a time. Eventually you will find one that spurts a bunch of air.

After all the playing with city water, go back to the fresh water tank. Dump any air in that line the same way.

Bob

OK, thanks for the quick responses. I've hooked up to city and run each of the faucets, hot and cold for a long time. Also turned of the hwh and will drain some more hot water to rid the system of all of the hot water, then start the process again with the fw tank.

Question about the outside shower. Are all of the standard models pretty much worthless? By that I mean there is no pressure on either how or cold or both. It pretty much just dribbles out. And once you stuff the cord and head back into the compartment you've got to be very sure to turn H&C completely off. I'm wondering if the horrible flow is typical or if it might be an indication of something askew in those lines.

[bickp]

Originally Posted by GCinSC2

If you can get a simple water pressure test gauge and connect to the trailer exterior hose spigot (assumption 1 is that you have one) and add the pressure to your list of observation inputs. Home centers have them just a gauge and fitting combined.

Assumption 2 is that the pump is not building pressure easily to tell pressure switch OK turn off now. Hot water tank is bolstering system pressure fooling the pressure switch.

Did you notice the declared assumptions?

Gary

Hi Gary: thanks for the quick reply. I've got a pressure gauge. Going to run the uncle bob solution to the end to see if that works.

[JonDNC]

Originally Posted by bickp

Question about the outside shower. Are all of the standard models pretty much worthless? By that I mean there is no pressure on either how or cold or both. It pretty much just dribbles out. And once you stuff the cord and head back into the compartment you've got to be very sure to turn H&C completely off. I'm wondering if the horrible flow is typical or if it might be an indication of something askew in those lines.

Yes they. Are fair at best, but should be more than a trickle. Have you moved the little silver handle to the other position. It’s a water saver valve. You should have some flow but I’ve never had any real pressure

[Rich W]

Originally Posted by bickp

Question about the outside shower. Are all of the standard models pretty much worthless? By that I mean there is no pressure on either how or cold or both. It pretty much just dribbles out. And once you stuff the cord and head back into the compartment you've got to be very sure to turn H&C completely off. I'm wondering if the horrible flow is typical or if it might be an indication of something askew in those lines.

Keep the line attached to the connection but disconnect the shower head. Turn on the water and see if you have pressure. Test hot and cold. Your shower head may be clogged with deposits or you have the slide in the hold position.

[bickp]

Originally Posted by JonDNC

Yes they. Are fair at best, but should be more than a trickle. Have you moved the little silver handle to the other position. It’s a water saver valve. You should have some flow but I’ve never had any real pressure

Thanks for suggestion. I did know about the silver handle. Even when in the open position the flow would not be adequate to remove sand on someone's feet. I saw a recommendation for another but it was out of stock with no expected replacement date. Will keep looking.

[bickp]

Originally Posted by bickp

OK, thanks for the quick responses. I've hooked up to city and run each of the faucets, hot and cold for a long time. Also turned of the hwh and will drain some more hot water to rid the system of all of the hot water, then start the process again with the fw tank.
.

While on city water made sure that hot water had turned cold after turning of the hwh. Removed city water and turned on kitchen faucet to reduce pressure. Then turned on the water pump and it pumped for a short period then shut off as expected.

Thanks uncleBob. After sanitizing the system I ran the faucets for a very long time and could get no more air spitting in any faucet. But apparently there was some air somewhere. Good for now.

[uncle_bob]

Originally Posted by bickp

While on city water made sure that hot water had turned cold after turning of the hwh. Removed city water and turned on kitchen faucet to reduce pressure. Then turned on the water pump and it pumped for a short period then shut off as expected.

Thanks uncleBob. After sanitizing the system I ran the faucets for a very long time and could get no more air spitting in any faucet. But apparently there was some air somewhere. Good for now.

Hi

Glad it worked !!!!

There's also the chance that it just was crud in the pressure switch. Same flush flush flush usually fixes that as well. The strainer basket on the input to the pump that you clean out every year only catches some of the crud from the inside of the fresh water tank.

Bob

[JCWDCW]

Suggest you open the pressure relief valve and bleed air off the tank till you get a bit of water. Then close the relief
Worth a try
JCW

[PatLee]

bickp - you reminded me of something when you wrote about your outside shower. I have sometimes pulled out the hose to find that it is dribbling a little because the faucet doesn't tighten very well in the OFF position. I think traveling down the road loosens it as well. I've made a note to myself to duct tape the faucet so it stays in the OFF position. I can see how a loose shower faucet could make me think I had a leak. BTW - my outside shower hose actually works well - not a "fierce" flow but good enough for rinsing sand off my feet and the pup. Turning on your water pump could also improve the flow. One more BTW - I had it replaced during one of my JC visits with a nice stainless steel one and the fixture seems to be of higher quality and wraps up more easily when storing.

[djbar]

PatLee: What make/model replacement did you use for the outside shower faucet/hose?
Thanks!

[PatLee]

debar - I got the one that they sell in the Airstream Store at Jackson Center, OH during one of my warranty visits. It seems to have been specifically designed to fit our Airstreams. Warning: it added yet another key to my AS key ring. Ha!