Blowing out plumbing - How to hook up system?

[101mph]

Hi Guys,

I have a cottage that is on a crawlspace and is a single floor (around 900 sq. ft.). I would like to blow out the plumbing in the cottage when we shut the place down for the winter. I’d like to install an air fitting somehow so that I can use an air compressor to blow out the water in the system.

We are on a well. The well goes into a holding/pressure tank and from there into the rest of the house plumbing (hot water tank, faucets, shower etc.).

Where in the plumbing should I put the fitting to hook the air compressor to when I want to do this?

What type of fitting should I use and how much air pressure do I need so I can size the air compressor properly? I would imagine a small one would most likely do the job but I’m not sure.

I was thinking the procedure to do this would be as follows:
- Shut off well pump
- Open faucets to let water out and de-pressurize the system/holding tank
- Hook up air line/compressor and blow out remaining water in system

Sound about right?

Thanks.

 

[Stuart in MN]

If you can adjust how the water lines so they are sloped down to a tap at the lowest point, you can drain the system by gravity - we had a lake cabin when I was a kid and that's how we drained the water every fall, never had any problems with freezing. Also, don't forget to put some RV antifreeze in the sink traps and toilet.

 

[jkwilson]

^^Gravity is best. If the system is already there, you are going to need a valve at the water source so you can drain all of the lines anyway.

I gravity drain mine, then attach a shop vac blower port to a stub on a valve at the shower head, and open all of the faucets and start the air flowing. The high volume low pressure of the shop vac is better than a compressor that could damage plumbing if you don't throttle the pressure down. When nothing is spitting water, I start closing faucets until only the shower and the drain are open.

Don't forget to replace the water in your traps and toilets with antifreeze.

 

[gordo9742000]

I do the same thing every year. My procedure is to shut of the main. drain the water heater and pressure holding tank through the spigot at the bottom. I shut off the valve right after the pressure tank. I tapped into the line right after that valve and put in an air fitting. Shut off the toilet valves and drain the toilets. Turn on compressor and set the pressure at 45 psi. Let it run till system is pressurized and then start cracking all the faucets one at a time. Fill traps and toilets with antifreeze and call it good. Whole process takes two beers at the most. I am sure other people will tell me I am doing it wrong but it works for me.

 

[yeldogt]

I do as gordo.

To have everything open requires a large (very) compressor to provide a huge amount of 50psi air. That is what they use on my pool and lawn sprinkler system - the kind that you see on construction sites -- towed behind a truck. It takes about 10 seconds per leg with one of those.

You should have a drain around the pump. When you do as gordo - the hot water tank becomes a second air tank --- that volume of air is what clears out each run. In my house I have to "fill" up the water heater with air more then once.

If you have a dishwasher or clothes washer make sure you cycle it so the valve opens -- they will/can freeze and crack.


I do the RV antifreeze in the toilets and other drains -- some people do the dishwasher.

 

[sberry]

Use a silcock to hook on if there is outdoor water. It doesn't take a huge amount of air and you can let it build and give it a couple shots, you can aso take a section of rubber hose and slip fit over a faucet. Don't worry about blowing it up, with a hydrant open it will never reach full pressure.
I like a valve at the end so I can whoosh it, give it a couple blasts.

 

[RECox286]

Blowing out the pipes is how we winterized all the houses that we took

care of, here at the Jersey Shore. We started out with a 1hp twin

cylinder compressor and ended up with a street compressor. (It just

made it easier and quicker to blow out irrigation systems.) Volume and

not pressure is the trick, as you don't want more than 90psi b/c of

plastic piping and plumbing parts. I made up an adapter that I could

attach to an outside spigot and then plug an air hose quick disconnect

fitting to the other side. Turn off the water supply at the street, or

turn the water pump breaker off, hook a garden hose to the drain fitting

at the bottom of the water heater and start by adding air to the cold

or hot side of the plumbing, it makes no difference. Once the w/h is

empty, you can use the w/h as an air reservoir to blow out the rest

of the pipes via the faucets and toilet supply valves. When the pipes

are empty, use a small bilge pump to empty the toilet bowl(s) and

tank(s). If you have a dishwasher, and clothes washer you will want

to blow out the supply piping and related valves before removing the

air pressure, then run the appliances thru their drain cycle. If you have

a refrigeratior with water in the door and icemaker features, then you

will want to run the water out of the related supply valves and piping

before you remove the air pressure. If you have a hydronic heater

(boiler and radiation) you will want to either have it filled with boiler

antifreeze, or have it blown out, which you can do with your compressor.

If you have hot air heat, with a humidifier, then you will need to evacuate

the water out of its' piping and fill valve. If you have a well, the last thing

to do is drain the pressure tank, and recheck all spigots and drain fittings

to make sure that you have all the water out of the system. The first go

round will be the hardest, until you have the drill down to a system. I use

to start at the top of the home, and work my way down to the ground level.

Then when the water was completely drained, I would go back with the

antifreeze to do traps, toilets, showers, spas, dishwashers, clothes washers,

and any other water filled devices that we couldn't guarantee w/o freeze

protection.

Any other questions ? If so, then give me a hoot.

Uncle Bob


BTW: No, we never lost any plumbing or appliance to cold wx, and never

had to "fix" anything in the spring. (Other than the ususal odd faucet

washer or the like.) If you are diligent and thorough, then you too should

have no problems either.

 

[101mph]

Thanks guys.

I do have a couple valves in the crawlspace that I can use to gravity drain from there. I'm just concerned that there may still be some water left in the lines as I don't know for sure if the original owner had all the lines pitched correctly to them.

I also am concerned that there will still be some water left in the holding tank (or elsewhere) that could possibly freeze (that's why I'm thinking about using compressed air to evacuate the system completely).

There is a spigot at the bottom of the holding tank that I can drain from.

I haven't looked into any compressors yet but I would think that you can control the pressure that you're putting into the system (at least I hope this is the case).

Would it be safe to say that I can have the air fitting after the pressure tank and let the spigot at the bottom of the tank take care of draining that or should I use compressed air to get rid of the water in the tank too?

Could I possibly use the spigot outside of the house to hook the air compressor to? I'd have to come up with some sort of connector/adapter.

Sorry about all the dumb questions Just trying to find the easiest way to do this. I'm relatively handy, but not much of a plumber and frozen/cracked pipes scares the **** out of me.

 

[abachman]

Just go to a mobile home (trailer) dealer and get a fitting that goes on to the Hose outlet and it is made to add air, like tire valve. That's how travel trailers and mobile homes are winterized.

 

[gordo9742000]

its safe to put the air fitting after the tank. The spigot is at the lowest point of the tank so it should drain it completely. I leave my compressor hooked up year round in my crawl space. Got it set up with the valves and a switch under kitchen sink. Flip a couple valves and a switch and the process begins. I only use a small pancake compressor. Sure a bigger one would be quicker but I am in no hurry.

 

[Milton Shaw]

Nobody has mentioned this in any of the post.. Make sure the water heater is turned off at the breaker or gas valve, otherwise you are going to ruin it. In the spring make sure the water heater is full before you turn it back on too. It's easy to forget in the rush of winterizing especially if you waited until its freezing outside.

 

[101mph]

Nobody has mentioned this in any of the post.. Make sure the water heater is turned off at the breaker or gas valve, otherwise you are going to ruin it. In the spring make sure the water heater is full before you turn it back on too.

Yes, thanks for the tip. We are all electric there.

Definitely already doing this

 

[Lippyp]

I drain my holiday home each fall for the winter. Its three stories and I have an outside tap that is the lowest point in the cold water system in the house so I drain the cold from there, the water heater has a drain at its bottom so the hot water system is drained back through that. A little water in the pipes is OK as long as theres space for it to expand if it does freeze. I just turn the mains supply off and then open the lowest tap and then open the rest and run until nothing else comes out. The only damage we've had was one shower mixer that froze and cracked as it wouldn't drain properly but I use the cheapest ones I can get now so if it does freeze it's no big deal. I've seen -16C there so it does get pretty cold at times. We don't seem to be able to get RV anti-freeze here easily so I just dump a pound of salt in the toilet trap andwedge a plastic bottle in the trap which apparently should stop it cracking the pan if it does freeze despite the salt.

 

[Sureshot]

Blow it out with air then chase a gallon or two of RV antifreeze through it. Any water left will be diluted with the antifreeze and cause no problems.

 

[smokem2020]

I blew mine out last year. I had two problems. One 45 degree fitting that was the lowest point and the tub leg on the shower faucet that was capped. Water couldn't drain from that and split the cap. I'd put some antifreeze in minimize freezing the low points and pockets that can't drain. If anyone has a water softner they need tipped to drain. I screwed an air spud to my hot water heater pressure relief valve. I thought I did a good job till I turned on my well pump. Had to clean all my screens on my kitchen and bath fausets. I also unhooked my toilet supply line so the fill false wouldn't freeze. Any filters or RO need removed and drained. Hope this helps