To blow out or not to blow out, that is the question

[TTnewbie]

I am going to winterize my TT soon and wanted to get some insight into whether or not I should blow out the water lines before filling the lines with antifreeze. I was planning on doing so but came across a couple of posts mentioning damage that can result from blowing out the lines.

[Skip12]

You will get a lot of different opinions. You're goal is to get all water out of the plumbing. There are a few ways to accomplish that.

I've seen very few posts regarding damage from blowing out the lines. Seems like damage could happen from too much pressure or not getting all the water out. So, watch your air pressure and since you plan on using antifreeze after, that will give you a second chance to get the water out.

Hope that helps.

[TTnewbie]

Originally Posted by Skip12

You will get a lot of different opinions. You're goal is to get all water out of the plumbing. There are a few ways to accomplish that.

I've seen very few posts regarding damage from blowing out the lines. Seems like damage could happen from too much pressure or not getting all the water out. So, watch your air pressure and since you plan on using antifreeze after, that will give you a second chance to get the water out.

Hope that helps.

Yeah, every question asked on this site gives you a plethora of answers and opinions.

If I blow the system out and then fill it with antifreeze then what is the point of blowing it out in the first place? Am I missing something? Or do people blow out their system and leave it "dry"? This is the first time that I am doing this.

From what I understand, if I open up the drain valve and use the water pump to get the antifreeze in the system it will fill all of the lines. Will the water that is in there already get pushed out of the drain valve in the process? Is it better to blow it out completely and then fill the lines?

I called my local RV dealer and they charge $150 to winterize a TT. I find that to be an astronomical price for the few gallons of antifreeze involved.

[Mr. Dan]

Originally Posted by TTnewbie

Yeah, every question asked on this site gives you a plethora of answers and opinions.

If I blow the system out and then fill it with antifreeze then what is the point of blowing it out in the first place? Am I missing something? Or do people blow out their system and leave it "dry"? This is the first time that I am doing this.

From what I understand, if I open up the drain valve and use the water pump to get the antifreeze in the system it will fill all of the lines. Will the water that is in there already get pushed out of the drain valve in the process? Is it better to blow it out completely and then fill the lines?

I called my local RV dealer and they charge $150 to winterize a TT. I find that to be an astronomical price for the few gallons of antifreeze involved.

What are you calling “the drain valve”? Many/most trailers have two low point drains (one for hot lines and one for cold), a fresh water tank drain, and a water heater tank drain.

[Iwritecode]

Originally Posted by TTnewbie

Yeah, every question asked on this site gives you a plethora of answers and opinions.

If I blow the system out and then fill it with antifreeze then what is the point of blowing it out in the first place? Am I missing something? Or do people blow out their system and leave it "dry"? This is the first time that I am doing this.

From what I understand, if I open up the drain valve and use the water pump to get the antifreeze in the system it will fill all of the lines. Will the water that is in there already get pushed out of the drain valve in the process? Is it better to blow it out completely and then fill the lines?

I called my local RV dealer and they charge $150 to winterize a TT. I find that to be an astronomical price for the few gallons of antifreeze involved.

You blow the air to get the water out first so you aren't diluting the AF. Then you pump the AF in because IMO, it's impossible to get *all* the water out with air only.

Some only do one or the other. Some blow out the AF right afterwards.

You'll now get about 100 replies from everyone else explaining how they do it.

[Sticki]

I'll either blow the lines out or add RV anti-freeze but not both and we're up in the Texas Panhandle where it gets pretty cold. No problems since 2012.

[John Hendrick]

I have been blowing out the lines for years without any real problem. The only place I use the anti-freeze is in the traps, using about one gallon total in five traps. I also take the filter bowl off my water pump as I had it crack one year from residual water.

[bzac1954]

Originally Posted by TTnewbie

I am going to winterize my TT soon and wanted to get some insight into whether or not I should blow out the water lines before filling the lines with antifreeze. I was planning on doing so but came across a couple of posts mentioning damage that can result from blowing out the lines.

Not going to mention all the possibilities but anywhere it may get below freezing for longer than an overnight time frame you run the risk of ruptured pipes. Your choices are: 1. Drain system from low point and take it for a drive to dislodge any residual water 2. Low point drain and blow the system down 3. Pump antifreeze into the system. With all, pour some in the P-trap.

Blowing down your system can rupture piping IF you use too much air pressure (40 - 45 psi) or you forgot to open a faucet somewhere and NEVER clip the air nozzle in place.

[DJohn]

My dealership wanted 190 dollars to winterize our motorhome. 20 bucks worth of antifreeze and about 30 minutes, done, and I did blow the lines out first.

[RussPastuch]

Being located in the frozen north, Canada, I always blow out the lines before putting in the antifreeze, being the cheap bugger I am. It lets me use less anti freeze and doesn't dilute the protection.

[msroll]

I've been blowing out water lines on everything I have owned including cabins, boats, RVs and never had a problem. I set the compressor to 30 psi and open the faucets and run it till the water is out then push the foot pedal on the toilet till only air comes out. Pour anti freeze on the drains and cover it up for a long winters nap.

[Trawlerphil]

I open the petcock on the fresh water tank, empty black and grey water tanks and then blow the lines clean slowly gradually increasing the air pressure. Next, I put some antifreeze in anything that has a trap and the most important thing which is to remove and drain the heads from the galley sink hose and the shower heads.

Lastly, I remove the anode and flush the hot water heater completely. I sand the anode a bit to expose new zinc and wrap it for next year. If the electrode is failing, now in the time to replace it.

[High Country Duramax]

Last couple years I’ve blown out first and then antifreeze. This year I drained using low points and filled with antifreeze. Three gallons get the job done, I always use five though. Opening each faucet a times alternating be between them and dump the extra in the toilet and traps.

[Tundra 2014]

I blow-out at 40 PSI making sure to do outside shower and toilet. Then dumping anti-freeze into drains/p-traps. Blow out can leave water in drains. Since the drains are larger in diameter, low risk of freeze damage. I feel better doing it and it costs $4 for a gallon of anti-freeze.

[TitanMike]

Originally Posted by John Hendrick

I have been blowing out the lines for years without any real problem. The only place I use the anti-freeze is in the traps, using about one gallon total in five traps. I also take the filter bowl off my water pump as I had it crack one year from residual water.

If one blows the lines out, letting air run long enough to really clear lines til there's no " fog" from outlets, lines are freeze proofed.

As for the drain traps take a tip from hot-tub manufacturers and blow sink and shower drains out using the exhaust of a shop vac or even leaf blower.

One can even blow fresh water tank to pump line back into water tank where it will drain through open drain valve.

Even water pump can be cleared of water by blowing it out through antifreeze suction port and running pump for a minute.

If one does a proper air blow out then antifreeze is totally unnecessary.

Nice thing about air blow-out winterizing is no need to flush.

[Chuck_S]

Heck, after I blow the water out of the camper's water lines I blow out the hoses I use in my garden even though they're pretty flexible.

I blow out my lawn irrigation system and don't know of anyone who fills the system with antifreeze. Nothing to freeze means nothing to freeze.

-- Chuck

[TitanMike]

Originally Posted by bzac1954

Not going to mention all the possibilities but anywhere it may get below freezing for longer than an overnight time frame you run the risk of ruptured pipes. Your choices are: 1. Drain system from low point and take it for a drive to dislodge any residual water 2. Low point drain and blow the system down 3. Pump antifreeze into the system. With all, pour some in the P-trap.



Blowing down your system can rupture piping IF you use too much air pressure (40 - 45 psi) or you forgot to open a faucet somewhere and NEVER clip the air nozzle in place.

The water system was pressure tested for most likely 80 psi or more.

Just use a regulator if you have a big enough compressor to keep pressure that high.

[Foothills]

I second IWRITECODE: never can tell in some units if air does the job completely

[kawac14]

After bypassing and draining the hot water tank, I open the low point drains and then the faucets to drain as much water by gravity as possible. Then cap the drains and gently blow out the remaining water in the lines using a portable air tank. I bought an oil-free compressor to fill the tank because I didn't want my larger compressor leaking oil into the air lines. After blowing out the water lines, then I pump about 1.5 gallons into the system until I see pink stuff coming out the faucets. Done. This is much faster since I removed the factory installed water filter from the line.

[TTnewbie]

Originally Posted by John Hendrick

I have been blowing out the lines for years without any real problem. The only place I use the anti-freeze is in the traps, using about one gallon total in five traps. I also take the filter bowl off my water pump as I had it crack one year from residual water.

How would I know if I have a filter bowl on my water pump? I have a Cherokee 26dbh.

I ask because I blow my irrigation system out myself with a 25 gallon air compressor. Its a slow process but I am able to get all of the water out. The first two years I did it the plastic stopper in the backflow preventer cracked due to sitting water that was left in it. Now I remove it so that it doesn't happen again. After reading your comment I can see how it would be possible for something with even a little water left inside a water pump can crack from freezing.