Air compressor for blowing out lines

[MNtraveler]

Anyone have thoughts on the size/capacity and duty cycle needed for a compressor that will be adequate to blow out the water lines in a 25' motorhome? I know the small one we have now won't do it. It shuts off in 2 mins or so as it has a small duty cycle.

Thanks!


Land of 10,000 Lakes
2016 Forester MBS 2401R
Nights camped 2016: 29; RV to date: 32

[RedLdr1]

A smaller sized compressor works fine for winterizing. Just keep the air pressure around 30PSI to avoid damaging your plumbing. I use this one from Home Despot with a pressure regulator to protect my plumbing.

[donniedu]

My 135PSI Porter Cable pancake does a fine job. You do not need nor want high pressure. You want 25PSI max.

[raptor]

I'm using my craftsman 15 gallons compressor. It has moisture collector and adjusted air pressure to 30 psi or less. It's huge, but I have long hose to reach the side of my house. Want to spend money for portable one, but it seems to work. It's also my first winterize.

[Orion]

I just got a small tank and regulator. Fill it up set the regulator and go


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[gfarmcafe]

I have a Dewalt, 3 gal air compressor from Lowe's that goes with us anytime we take the camper out. It's 110 V, capable to 155 lbs. I always fill it before we leave and check tires every day. Tool pressures can be turned down so I can blow out lines at around 30-35lbs without worrying about blowing apart fittings.

[TARVIDSON]

You only need a small tank because you pressurize the lines and only open one at a time so there is a fast squirt of air to clear it out. Open the hot water heater to drain, set the water valves for winter, drain your lines and hook up your compressor and set it for about 30#. I always used 40 with no problems but 30 is safer and works fine. Don't forget the outside shower and the toilet etc. Hang the shower hoses so they will drain and remove the heads. I broke the threads on my outside shower head because it was not removed. The other caveat is to use an oilless compressor. Not sure of the exact reasons but I would assume it has something to do with oil getting in your water lines. Be sure to pour antifreeze in your drains and gray and black tank. Turn on your water pump for about 30 seconds once early in the process and once at the end to make sure it is clear. If you are sucking antifreeze through the system a lot of this is not necessary, but I prefer not having the antifreeze in the lines, other people quite successfully use no air or use both. I go back around releasing air at least twice until there seems to be only a tiny mist at the most when you crack a valve. The whole process only takes about 15 minutes once you know the drill.

[Teamfour]

I'm able to blow out the lines using a good quality bicycle air pump.

[lakejumper]

I have this small compressor that I also carry with me. It is a one gallon Campbell Hausfeld FP2028 that I bought from Ace Hardware (all stores don't carry it). It goes up to 100psi but you only need a few lbs of psi for blowing out your lines. This can be adjusted on the compressor. I have a larger Porter Cable compressor that I keep at home that can also be used.

[camaraderie]

Harbor Freight has a 1/3 HP 100PSI pump for $59.99...and this weekend they have a 20% off on line coupon. For an adjustable occasional use pump that is pretty hard to beat.

3 gal. 1/3 HP 100 PSI Oilless Pancake Air Compressor

[gfarmcafe]

This may be "overkill", but I will drain the lines and water heater, blow the lines of any excess water, then suck anti-freeze though out, drain it again and blow out everything. This will insure no water left in any low points and I won't have any aftertest of anti-freeze next Spring. So far no problems! I do this because of a very costly replacement of a Aquahot system we had in a Beaver diesel pusher a few years ago that wasn't properly winterized.

[lakejumper]

The Campbell Hausfeld compressor I mentioned above is small and compact and is also available at Lowe's.
Shop Campbell Hausfeld 0.2-HP 1-Gallon 110-PSI 120-Volt Pancake Portable Electric Air Compressor at Lowes.com

[RamblerGuy]

I bought an oil free Porter-Cable 150 psig compressor with a 6 gallon tank at Home Depot on sale for $99. 150 psig is great for pumping up the coach tires and it drives my impact wrench very well, although not for long. My old shop compressor didn’t get it since it doesn't restart until it's down to 80 psig.

[pmsherman]

I blow out my water lines using a 125psi Sears tankless compressor that is kept in the RV. There's a pressure regulator built into the hose which I set to 30psi when doing this.

I tried using one of the small HF pancake compressors in the RV but gave up on it when I discovered that he compressor didn't come on until the tank pressure dropped to 80psi. Unfortunately, this isn't high enough to top off the RV tires.

Phil

[thundrr1]

What about using a Shop Vac to blow out the lines? The pressure is not really that high and the volume of air should move the water out. Thoughts???? Yes, I'm a newbie.
.
Thanks,

George

[ScottBrownstein]

I don't think a Shop Vac will work. First of all, if you connect it to the city water connection, which is where compressor blow out is normally done, it will not have enough pressure to open the check valve. If you connect somewhere else, I would worry that the small lines (reefer and icemaker which are 1/4) won't clear at all.

Stick with a real compressor and set it to 20 or 25 pounds of air pressure.

[noslofivoh]

Originally Posted by camaraderie

Harbor Freight has a 1/3 HP 100PSI pump for $59.99...and this weekend they have a 20% off on line coupon. For an adjustable occasional use pump that is pretty hard to beat.

3 gal. 1/3 HP 100 PSI Oilless Pancake Air Compressor

I use the oil less 150 psi version of this with a regulator. I leave this compressorbin my basement also. It is great other small repairs including airing the tires in my TV and fiver. I also use it with a blower nozzle to clean off my roof, slides, and clean my gutters out.

[RedLdr1]

Originally Posted by thundrr1

What about using a Shop Vac to blow out the lines? The pressure is not really that high and the volume of air should move the water out. Thoughts???? Yes, I'm a newbie.

My old Sears shop vacuum blows out a ton of dust, and other "stuff", when I set it up for blower mode. I would not want that "stuff" getting in my water lines! A newer, cleaner vac might not be as bad as my oldie but I would be very hesitant to try it...

[jgourlie]

Everyone is using 30psi. That is good to know. I set my compressor to 40 to blow out the lines. Time to turn it down a bit. Good tip

[RamblerGuy]

Originally Posted by jgourlie

Everyone is using 30psi. That is good to know. I set my compressor to 40 to blow out the lines. Time to turn it down a bit. Good tip

What's the problem with 40 psig? The system is rated for at least 150 psig and is protected at 150 psig by the water heater pressure relief valve. You won't hurt the system with any pressure up to 150 psig, you'll just blow water all over if you leave a faucet open or when you open it. If you're comfortable with 40 psig, use it. If you like 30 psig and it clears your lines, use it.

Consider the argument that you need a pressure regulator on the incoming city water line or you'll have leaks. Why? You can get high pressure on the system anyway. If you use hot water and the water heater then heats water with no faucets open, the expansion of the water will cause the pressure to rise. If there's not enough air in the water heater to absorb this expansion, the pressure can cause the relief valve to weep until the pressure drops. I have that happen often and it's never caused a problem with the plumbing. It can make it hard to open the toilet water valve, but I just reach over and open the hot water on the sink for a second.