Air in water lines

[hoop1252]

I went on my first camping trip this week with my new to me 2018 Cruiser stryker 2313. Used the bathroom a few times, everything seemed fine when i flushed the toilet. Then later on during the day had no water pressure. Check kitchen, bathroom faucets , all the same. Could hear pump running. My son was with me and said he used the bathroom sink earlier to wash his hands and everything seemed fine. Since it was a used trailer, I decided when I bought it , I would get a spare water pump since I have no idea how often it was used. I boondock only and I wouldn't want to be without water. I also got a $40.00 parts voucher from dealer. Before I got started switching out pump tried it again and worked fine. Only thing was on the hot water side it wouldn't stop surging, cold side seemed fine. Just so you know I didn't have hot water tank turned on to heat water. Today I decided to install new pump to see if anything changed. I checked inlet filter when I did the swap and it was clean. When I first turned on pump to check for leaks, pump run for a awhile to fill up lines and then stopped, just like it supposed to. No leaks . turned on hot water, water heater still off, still a lot of air in lines, run it for over 5 minuets still a lot of air, now cold side has air in it. When I was swapping the pumps out I noticed the valve from the line coming from tank to inlet side of pump. then other line off the valve is not connected to anything just an open ended line. Figured this was to winterized water line and the open end would go into antifreeze jug, rotate valve and pump would suck out antifreeze. I decided to put the open end line in a bowl of water and with the valve in line with fresh water line and if the level in bowl went down then the valve would be bad, plus with open ended line in water if the valve was leaking, it would stop surging. Water level remained same in bowl, but still a lot of air in system. Shut of faucets, went outside to hot water tank and opened up relief valve. A little bit of air came out then water, could here pump running. Went back inside turned on hot water , no air for first few seconds then started with the air again, same on cold water side. Any body have idea what else to check. I've had other rv's and when I fill fresh water tank, turn on pump, usually within a couple of minutes air is all out of lines, both hot and cold. Thanks for any ideas on this. .

 

[rvkev]

Sounds like a puzzle to me. You are possibly drawing air from before the pump? Maybe one freshwater tank is empty? Cracked diptube in tank? Poor connection prior to the pump? Pump housing cracked?

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You are correct to purge the top of the hot water tank with the pressure relief.

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Follow up here when you solve the mystery.

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GOOD LUCK

 

[hoop1252]

Sounds like a puzzle to me. You are possibly drawing air from before the pump? Maybe one freshwater tank is empty? Cracked diptube in tank? Poor connection prior to the pump? Pump housing cracked?

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You are correct to purge the top of the hot water tank with the pressure relief.

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Follow up here when you solve the mystery.

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GOOD LUCK

I see no leaks by pump so I don't think it would be a cracked housing. I'll see if I can get to where lines connect to tank, there's a hole in floor right by pump where lines go to tank. thanks for the ideas.

 

[TheLooks]

The line and valve are for winterization and is great. I definitely think the problem is on the suction side of the pump or you would have a leak somewhere and then the pump would not shut off. Check each clamp carefully. IF you have the lines that are braided in any color, they don't clamp worth a s*&$. We replace many of them on new rigs.

 

[hoop1252]

On the section line where the diverter valve and swivel elbow connect to hose, found that hose would spin on fittings. The clamps on these connections are the crimp type, going to change them to radiator hose clamp type.

 

[TheLooks]

Don't like radiator hose clamps, but not much choice here as the stainless ring clamps don't seem to crimp hard enough. The hose is 2 pieces and larger in diameter then the barb. Just a poor material they use because it bends in curves.

 

[BGMAC]

If you were winterized and air was blown into the system, it could take a while to get the air out. I have a large hot water tank and I will not get anything for a while, then spit and sputter.

 

[hoop1252]

Fixed! Put on new clamps. Also removed inlet filter. with the new pump installed no more air. Pump worked as advertised. Decided to remove new pump and install old pump without inlet filter. Same results, no air and pump worked fine. Installed inlet filter, tried again air in lines and pump wont shut off, it slows down put keeps on running. removed filter again and all is fine. Just ordered new filter. Can't see any cracks in filter housing or bowl, seal looks good, but must have something wrong with it. Thanks for all suggestions

 

[tdkkart]

The stainless band clamps are OK, in their place. Their place is on the exact hose and fitting combination THAT clamp was designed for. They are not universal for just any size line. The clamp was designed to only squeeze so far, once you need more squeeze than that you need a different clamp.
The plumbing I've seen in most RVs I've looked at is an absolute disgrace. Just saw a YT video last night where the guy was struggling to work on his RV because the plumbing was just a disaster. One thing I noticed was that while it had "lo point drains", the plumbing was in no way routed towards those drains, all kinds of low spots throughout the system for water to get trapped in.
I can already see that when I finally get done researching and finally buy an RV, one of my first projects will be a refit of the entire plumbing system, probably followed by electrical.

 

[rvkev]

Purchase the better quality "Constant torque hose clamp" There is clamp on the inside and a spring for torque.

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BREEZE Constant Torque Worm Drive Hose Clamp | Stainless Steel Clamp