I used my unit all last winter for the first year since buying it and put it away in the spring. I winterized back in September by blowing the air lines. i was careful not to exceed the recommended max. pressure in clearing the lines and followed the owners manual instructions. We are now south for the winter and after filling the fresh water tank immediately found that water would not run smoothly because of air in the lines and the pump would not shut down. I even replaced my Aquajet pump with a brand new spare thinking the diaphram was maybe punctured but both run the same. I checked the debris screen at the pump intake but it was clear and I can see air in the wet bay lines leading to the pump. I cannot trace the intake line fully through the coach back to the fresh water tank (FWT) but the line coming from the FWT does not show air bubbles. There is no water leaking under the coach which would indicate a ruptured line.After 2 weeks on the road, the air is slowly clearing from the lines and the pump is starting to shut down on demand but it has been a really slow process.One thing I have decided is that I will winterize using RV antifreeze next year. Any suggestions and does anyone else have this problem?

just hook up to city water and bleed each faucet one at a time and all the air will purge out. The hot water tank the same way. Been blowing out the line since 1977 this way and it always works. No issues. If you put in antifreeze then you are going to have to really flush it all out prior to use. Trying to use the pump is what cause your issue.

Sounds more like air in the pump intake rather than outtake. 2 weeks? Should be more like 2 minutes.

I use air only every year. Come first use, I just open each faucet (hot then cold) and the toilet to bleed the air from the lines. Never an issue after the few minute procedure.

It normally is not problem to purge air from the lines. You must have something strange going on. I used to have similar problems because of where my pump was located. It was positioned about 12' away from the tank which is too far (pump specs say 10' max but I think that's too far for good operation). Think of the straw trick where you put your finger over the top and hold the fluid in as you lift it out of the glass. Turn that straw on its side and the fluid dribbles out. The supply line has the same issues. In my case the pump was so far away that it had a hard time priming and then after shut the flow off, the pump would lose its prime as the water dribbled back into the tank.My fix was to move the pump to being directly over the tank. This solved all the problems and allowed it to prime immediately.Hope this helps.Scott

Do you use your hot water in the coach? It might take a while to replace 6 gal of air with water. I wouldn't fire the water heater until air is purged. With gas it won't matter as much but an electric element will fry. Just open up a faucet and bleed it. It will take a few minutes depending on gpm. I would agree that it's easier to do this on city water than via the onboard tank and pump.

Air in water lines | Good Sam Community

12 Replies

rgatijnet1
Explorer III
Nov 19, 2014
djbroughton wrote:
rgatijnet1 wrote:
Did you check to see if your fill valve was in the pump position rather than shore water position?

Ok, I was trying to think that one through and tried it both ways with no change. What difference does it make to switch between city water and tank position?

Dave

If the fill valve is left in the shore water position, without shore water connected, my Monaco coach pump will run continuously.
djbroughton
Explorer
Nov 19, 2014
rgatijnet1 wrote:
Did you check to see if your fill valve was in the pump position rather than shore water position?

Ok, I was trying to think that one through and tried it both ways with no change. What difference does it make to switch between city water and tank position?

Dave
wclement1248
Explorer
Nov 18, 2014
If you have a siphon hose for adding antifreeze. check to see if it partially open. The pump may be sucking air.
rgatijnet1
Explorer III
Nov 18, 2014
Did you check to see if your fill valve was in the pump position rather than shore water position?
Hondavalk
Explorer II
Nov 18, 2014
As MountainAir05 said, hook up to city water and open the hot water faucets. That water heater holds a lot of air. Also make sure the valve for your winterizing hose is closed
wa8yxm
Explorer III
Nov 18, 2014
Not so much the lines as the water heater.... Back when I had an ice maker if the thing cycled my water pump would come on 3 times. But if I drained the water heater and then refilled it till the air cusion in the water heater eventually went away the pump would continue to run much longer when it ran, but it would only run one or two times on an ice maker cycle.

This is normal, and not a problem, In fact. Normally the pump starts a bit after you open a faucet and stops a bit after you shut off but if the air cushion is big enough it can take a couple seconds to kick in and around half a minute to 1 full minute to cut off.

Air in the INtake line will make it run longer, but filling the on-board supply tank FULL should clear that on the first pump run.
willald
Explorer II
Nov 18, 2014
We use the air/compressor method for winterizing, always have. Never had the issue described here.

However, here is I think where the difference may be: Even though we blow out all lines with air compressor to winterize, before doing that, I pump just a little bit of antifreeze through the water pump, just enough to fill the pump itself and its input line with antifreeze to protect it from freezing. Once that is done, I hook up compressor and blow out the lines.

I am hesitant to push compressed air through water pump (from input side), so letting it pump a little antifreeze through is only way I know of to get water out of the pump itself and protect it from freezing. Soo, even though we use compressor blow-out method, my procedure has still always been to use just a little antifreeze in the pump, to protect it (as well as in all the drain traps, obviously).

Anyway, might want to try this approach next time, see if that doesn't help. Perhaps the pump having some antifreeze in it will 'prime' it a little better, and allow it to start pulling water through easier when you get it back out in the Spring.
Effy
Explorer II
Nov 18, 2014
Do you use your hot water in the coach? It might take a while to replace 6 gal of air with water. I wouldn't fire the water heater until air is purged. With gas it won't matter as much but an electric element will fry. Just open up a faucet and bleed it. It will take a few minutes depending on gpm. I would agree that it's easier to do this on city water than via the onboard tank and pump.
ScottG
Nomad
Nov 18, 2014
It normally is not problem to purge air from the lines. You must have something strange going on.
I used to have similar problems because of where my pump was located. It was positioned about 12' away from the tank which is too far (pump specs say 10' max but I think that's too far for good operation).
Think of the straw trick where you put your finger over the top and hold the fluid in as you lift it out of the glass. Turn that straw on its side and the fluid dribbles out. The supply line has the same issues. In my case the pump was so far away that it had a hard time priming and then after shut the flow off, the pump would lose its prime as the water dribbled back into the tank.
My fix was to move the pump to being directly over the tank. This solved all the problems and allowed it to prime immediately.

Hope this helps.
Scott
boogie_4wheel
Explorer
Nov 18, 2014
I use air only every year. Come first use, I just open each faucet (hot then cold) and the toilet to bleed the air from the lines. Never an issue after the few minute procedure.

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Air in water lines

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