Winterizing using water pressure regulator

**DaveBo** · 09-04-2019, 09:34 PM

I have a Viair compressor that does not have a pressure regulator. Can I avoid buying an air pressure regulator and a bunch of fittings by putting a water pressure regulator between the blow out plug and the water connection on the trailer? I’ve seen this recommended in a couple of places on the internet but don’t know if it’s is a valid approach to restrict the pressure.

**boyscout** · 09-05-2019, 08:17 AM

Originally Posted by DaveBo

I have a Viair compressor that does not have a pressure regulator. Can I avoid buying an air pressure regulator and a bunch of fittings by putting a water pressure regulator between the blow out plug and the water connection on the trailer? I’ve seen this recommended in a couple of places on the internet but don’t know if it’s is a valid approach to restrict the pressure.

I'm going to *guess* that this will not work and flag @Cate&Rob with this post since he probably *knows* the answer.

However while you're waiting for him why don't you price out the air system regulator if you haven't done that? I remember paying about US$20 for it at a Home Depot in Florida and have used it several times in less than two years with the satisfaction that I was properly protecting the system. Also consider something that Rob has told me: while your water system can handle 40-50 psi of water pressure, 40-50 psi of air is much harder on it and might damage it. I've dialed my air regulator down to 20 psi and it seems to blow the lines out just fine.

Good luck. We had a temp of three degrees C last night... pisses me off that we Canadians have to be thinking about winterizing already.

**Cate&Rob** · 09-05-2019, 08:27 AM

Originally Posted by DaveBo

I have a Viair compressor that does not have a pressure regulator. Can I avoid buying an air pressure regulator and a bunch of fittings by putting a water pressure regulator between the blow out plug and the water connection on the trailer? I’ve seen this recommended in a couple of places on the internet but don’t know if it’s is a valid approach to restrict the pressure.

Hi Dave,

To "blow out" a plumbing system with air, you need a high volume of air at a relatively low pressure. As Mark mentions, 20 psi is more than enough. But . . . a small compressor (like a Viair) does not have enough air volume at any pressure, to do this effectively.

When I rebuilt my plumbing system, I blew out the lines before disassembly (with my high volume shop compressor). I was amazed at how much water was still in the system when I took it apart. Particularly in the pump and adjacent lines (which blowing out the city feed system does not reach). Some get away with "winterizing" with air because Pex tubing and the soft hose will tolerate freezing with water inside. Other components may not.

Antifreeze is what the factory and the dealers use . . . it is the only completely safe way to winterize. This is cheap, easy and assures complete freeze protection of all lines and components.

Rob

**DaveBo** · 09-05-2019, 10:18 AM

Originally Posted by Cate&Rob

Hi Dave,

To "blow out" a plumbing system with air, you need a high volume of air at a relatively low pressure. As Mark mentions, 20 psi is more than enough. But . . . a small compressor (like a Viair) does not have enough air volume at any pressure, to do this effectively.

When I rebuilt my plumbing system, I blew out the lines before disassembly (with my high volume shop compressor). I was amazed at how much water was still in the system when I took it apart. Particularly in the pump and adjacent lines (which blowing out the city feed system does not reach). Some get away with "winterizing" with air because Pex tubing and the soft hose will tolerate freezing with water inside. Other components may not.

Antifreeze is what the factory and the dealers use . . . it is the only completely safe way to winterize. This is cheap, easy and assures complete freeze protection of all lines and components.

Rob

Thanks. I am planning to use anti-freeze. I only want to use air to blow out the fresh water fill and black tank rinse lines. I’d rather not buy and carry another compressor just for this unless necessary - would a hand pump work for this?

**Cate&Rob** · 09-05-2019, 10:47 AM

Originally Posted by DaveBo

Thanks. I am planning to use anti-freeze. I only want to use air to blow out the fresh water fill and black tank rinse lines. I’d rather not buy and carry another compressor just for this unless necessary - would a hand pump work for this?

Hi Dave,

There are several different antifreeze hand pumps, exactly for what you describe. Attached is the "Canadian Tire" link (for us Canadians

)
https://www.canadiantire.ca/en/pdp/a..._wcB#store=460

Rob

**DaveBo** · 09-05-2019, 07:57 PM

Originally Posted by Cate&Rob

Hi Dave,

There are several different antifreeze hand pumps, exactly for what you describe. Attached is the "Canadian Tire" link (for us Canadians

)
https://www.canadiantire.ca/en/pdp/a..._wcB#store=460

Rob

Since I don’t need to hand pump anti-freeze, just air, I think I will try using an air mattress pump with a water bandit fitting. I tried it on a garden hose, seemed to work okay. I wouldn’t want to do all the lines this way, but for the fresh fill line and the black flush line, I hope it’s good enough.

**Cate&Rob** · 09-05-2019, 08:13 PM

Originally Posted by DaveBo

Since I don’t need to hand pump anti-freeze, just air, I think I will try using an air mattress pump with a water bandit fitting. I tried it on a garden hose, seemed to work okay. I wouldn’t want to do all the lines this way, but for the fresh fill line and the black flush line, I hope it’s good enough.

Hi Dave,

The black flush line is “self draining” by design. When you remove flush water pressure, the high mounted vacuum break opens, allowing the flush water on the tank side to drop into the tank and the water on the supply side to drop back out the hose connection.

Rob

**iproff1** · 09-22-2019, 02:22 PM

Originally Posted by DaveBo

I have a Viair compressor that does not have a pressure regulator. Can I avoid buying an air pressure regulator and a bunch of fittings by putting a water pressure regulator between the blow out plug and the water connection on the trailer? I’ve seen this recommended in a couple of places on the internet but don’t know if it’s is a valid approach to restrict the pressure.

If you don't have an oil less compressor you need a filter to avoid putting compressor oil into your water system. I bought one with a pressure regulator on it. I blow out my sprinkler system at home with it also.

Sent from my SM-G960W using Tapatalk

**warsw1** · 09-22-2019, 06:51 PM

Originally Posted by DaveBo

I have a Viair compressor that does not have a pressure regulator. Can I avoid buying an air pressure regulator and a bunch of fittings by putting a water pressure regulator between the blow out plug and the water connection on the trailer? I’ve seen this recommended in a couple of places on the internet but don’t know if it’s is a valid approach to restrict the pressure.

I do just that. I use an adjustable water pressure regulator (set at 30 psi) and it works really well. I do agree that the Viair compressor will not put out enough volume to do a very good job of blowing out your water lines.

**powerscol** · 09-22-2019, 09:21 PM

I blow my system out with air and then add the antifreeze. Did it today. While using the air I was surprised how much water was in the line to the hot water heater that the air blew out after using the bypass. I do the initial blow out on winterize, and then do a bit on city water set up so the line to the HW tank is blown free. Was able to get the pump to prime easily withe antifreeze too. Filled the suction hose and held it high and cycled the pump. I have the compressor set to about 30 - 35psi - it has a storage tank and regulator.

Even after blowing out with air there was still a lot of water pockets that came out of the faucets as I cycled them imputing the antifreeze. Even the low point drains had a lot of water before the antifreeze cam out.

Its ready for winter - just need to get the awning arms attached correctly. Its currently bowed a bit - but that is another tail for later.