Clarify by-passing the water heater to winterize

[BicenTw]

When I bypassed the WH and removed the drain plug I did not see that much water exit the WH drain plug. Was it that I created a vacuum at the top of the WH tank thus keeping the water inside? I tried blowing air into the WH drain plug but only a little mist emerged. I followed some of the winterizing posts which gave the order of events as bypassing the WH, then blow out the system and add anti-freeze. Do I need to re do this procedure by draining the whole system again WITH the by pass valves open to the WH?. I understand the importance of not getting antifreeze into the WH.

[paiceman]

Actually the reason for the WH bypass is so that you do not waste money putting an extra six gallons of anti freeze in your system. I blow the whole system out including the WH then bypass the water heater and really blow out the lines.

It's worked for years, only started adding anti freeze to the system last year, before that just blew out the lines and added anti freeze to the traps.

Make sure you've blown out the outside shower.

Bud

[HowieE]

When the bypass valve or valves are set to the bypass position and you open the heater drain plug you should get about 4 gallons of water draining out of the heater. The water will gurgle out not flow out because of the partial vacuum in the tank, but it will come out. Only 4 gallons because there is some air at the top of the tank and some water remains in the bottom of the tank.

Possible problems.

The drain hole is blocked by scale. Put something, screw driver or stick, in it to ensure the hole is clear.

The heater never was full of water. While the bypass valve is in the summer position and the drain is open on the heater turn on the city water and make sure water is flowing into the heater and out the drain. This will test the valves for correct installation.

While it is not necessary I like to put a short length of hose, 1/4 in, into the bottom of the heater while draining it. This will siphon the water below the drain hole out of the tank. That water does not pose a freezing problem because of the shape of the tank.

[Protagonist]

Originally Posted by HowieE

When the bypass valve or valves are set to the bypass position and you open the heater drain plug you should get about 4 gallons of water draining out of the heater. The water will gurgle out not flow out because of the partial vacuum in the tank, but it will come out.

Handy hint, manually open the pressure relief valve at the top of the water heater first, then open the drain. Water will pour out quickly since air can get in through the pressure relief valve. Then close the pressure relief valve again after the heater has been drained.

[Rokitman]

[QUOTE=BicenTw;1720291]When I bypassed the WH and removed the drain plug I did not see that much water exit the WH drain plug. [QUOTE]

I get the same result from the water heater drain plug on my 2012 FC23FB. I open the low-point drain valves (interior under the pantry; exterior under the fresh water tank), the fresh water tank white petcock valve, and a faucet. I let them drain overnight. Next morning, I open the pressure relief valve and then pull the water heater plug...mostly, I just get a damp plug...that is, no water at all. Then, I blow out the entire system with compressed air, close the water heater bypass, replace the plug and close the relief valve. Then, close the low-point drains and continue with the antifreeze portion of the winterization process. Hope this helps.

[JCWDCW]

If you opened the drain valve at the back of the trailer that drains the piping around the water heater, it may have drained the WH if not on By-pass, since the cold water enters the bottom of the tank, and could therefore drain back out. I only just discovered the drain this year (2nd year winterizing on this unit just using antifreeze flush) I blew the system out with Air Pressure last year. Apparently a bit of water in the low point didn't do any damage.
JCW

[HowieE]

Originally Posted by JCWDCW

If you opened the drain valve at the back of the trailer that drains the piping around the water heater, it may have drained the WH if not on By-pass, since the cold water enters the bottom of the tank, and could therefore drain back out. I only just discovered the drain this year (2nd year winterizing on this unit just using antifreeze flush) I blew the system out with Air Pressure last year. Apparently a bit of water in the low point didn't do any damage.
JCW

Yes If you have drained the trailer with a low point drain and Opened at least one hot water faucet the heater will drain back through the cold water line. The important consideration here is that you have to have Opened a hot water faucet to release the vacuum on the system.

This is not a common way of draining the heater, and not an effective way to drain the trailer, but may be a third explanation as to why the original poster did not get any water out of the heater when he removed the drain plug if this was the case.

Please don't make winterizing this difficult.
Set the bypass valves.
Blow out the lines opening every faucet while applying air pressure.
Drain the hot water heater.
Pump in antifreeze through the water pump.
Put a cup or so of antifreeze in each trap
Drain the freshwater tank.

This should not take more than 15 minutes and I use less than a gallon of antifreeze in a large trailer.

[TopGeorge]

Originally Posted by Protagonist

Handy hint, manually open the pressure relief valve at the top of the water heater first, then open the drain. Water will pour out quickly since air can get in through the pressure relief valve. Then close the pressure relief valve again after the heater has been drained.

Be careful while the PRV lever is open/extended. Mine sticks out far enough that it interferes with the closing of the wh door. It could cause a dent from the inside out, if the door accidentally drops or is forced closed prior to the PRV lever being returned to closed position.

[BicenTw]

[QUOTE=Rokitman;1720360][QUOTE=BicenTw;1720291]When I bypassed the WH and removed the drain plug I did not see that much water exit the WH drain plug.

I get the same result from the water heater drain plug on my 2012 FC23FB. I open the low-point drain valves (interior under the pantry; exterior under the fresh water tank), the fresh water tank white petcock valve, and a faucet. I let them drain overnight. Next morning, I open the pressure relief valve and then pull the water heater plug...mostly, I just get a damp plug...that is, no water at all. Then, I blow out the entire system with compressed air, close the water heater bypass, replace the plug and close the relief valve. Then, close the low-point drains and continue with the antifreeze portion of the winterization process. Hope this helps.

[BicenTw]

Satisfied that there isn’t any measurable amount of water in the water heater and the system, pump and traps have ample anti freeze I can now settle down to a long winter’s nap. (not in the AS ) Thanks to all for adding comments. I believe I’ve got a systematic way of doing this next November.

[Eberheld]

Where is the bypass valve on the hot water heater in 2016 Airstream Grand Tour Ext.? I have removed the cup holder to look under the driver side under the lounge/bed and could not see or feel it. Thanks.

[Protagonist]

Originally Posted by Eberheld

Where is the bypass valve on the hot water heater in 2016 Airstream Grand Tour Ext.? I have removed the cup holder to look under the driver side under the lounge/bed and could not see or feel it. Thanks.

On the other Interstates, you access it by opening up the rear doors to reach under the bed from the rear. You will have to pull away some fabric, which is only Velcroed in place, then reach in between the water heater and the inverter enclosure.

Removing the cup holder is how you access low point drains.