What are the pros and cons of using air pressure to blow out water lines?

[RyanRving]

How do you blow the air out from the traps? Is that done differently than blowing out the lines?

[Crabman]

Originally Posted by RyanRving

How do you blow the air out from the traps? Is that done differently than blowing out the lines?

I would just pour some RV antifreeze in the traps, does not take much.

[dlfeather]

Originally Posted by RyanRving

How do you blow the air out from the traps? Is that done differently than blowing out the lines?

I have a 1.5 inch plastic cap with a hole on the end of the cap. I put it up to the drain and use a rubber tip blow gun and blow it out.

[Ranger431]

I just dump.a few cups of RV anti freeze in them.

[KachFam]

Older thread I know, bit though I would add 2-cents...

To avoid over-pressuring the lines, I start out with the compressor up to pressure and dial the overall pressure to a low setting (maybe 30 PSI or so). I never hook the compressed air up to the trailer unless I have a faucet open. I usually start with the water heater drain open to get a little more of the water out (probably not that important since it gets drained out anyways. This is the path of least resistance for the air so it pretty much all blows out of the water heater drain hole. Next, I go inside and open up a couple of faucets prior to placing the plug back on the water heater. I shut down faucets so only one at a time is open to blow out each line. I'm always careful to always have at least one open to keep from over-pressuring the system. I intermittently run the water pump through this procedure and it seems to get most of the water away from the pump area.

So far this method has worked great for me, although we don't get a lot of very cold weather like the midwest or far northern areas. Make sure not to forget about the outdoor shower nozzle lines also! I also put a couple cups of antifreeze in the drain traps and try to get enough in the gray and black tanks to prevent freezing of any residual fluids down there.

[Seann45]

you do not want to use air to blow out the traps... it will let stink back into the trailer... even if you have empty tanks there is a smell to them... just pour RV antifreeze down them... 1 cup per should do it