Required change to the winterization instructions?

[paulk-ESC]

ETI has made a recent change by adding a check valve to the cold water intake of the water heater as described here:

http://www.escapeforum.org/forums/f38/leaking-toilet-8746-3.html#21

My 2017 17b has this check valve. I think this requires a change to the winterization instructions. If you follow the instructions posted on ETI’s website and in the manual ( Winterizing Your Trailer ), then I believe the section of pipe between the lower bypass valve and the check valve on the water heater would be filled with water and could burst if frozen. This happens because the water in that section of pipe would no longer be able to drain into the water heater. The check valve requires pressure to open itself, if I understand it correctly.

The best solution that I’ve come up with is:
1) Bypass the water heater
2) Drain the water heater
3) Clear as much water from the pipes as possible using the interior pump. Eventually there should be a lot of air in the system
4) un-bypass the water heater. Assuming there is enough air in the pipes, this allows water in the problematic section of pipe to drain into the water system’s low point. You should be able to see if there is air by looking at the clear pipe coming from the pump.
5) Wait a while to allow the pipe to drain completely
6) bypass the water heater again

Thankfully, on my trailer this section of pipe is sloped in such a way that this will work. If that wasn’t the case, then I would need to remove the water heater’s anode and run the interior pump until only air was coming through the water heater’s check valve.

I'm making an assumption here that check valves don't allow water through if there is zero pressure on both sides of the check valve, which has been my experience with the check valve at the city water inlet. Anyone know if this is true?

Here are some pictures showing the area of concern:

 

[wetzk]

That valve I suspect is why you need to pop the pressure valve before you remove the anode.
I was surprised how much water came out.

 

[paulk-ESC]

That valve I suspect is why you need to pop the pressure valve before you remove the anode.
I was surprised how much water came out.

I believe you do that to allow air into the water heater as water exits the anode opening. I don't believe this would clear the water on the other side of the cold water intake check valve since that section of pipe isn't under pressure with the water heater bypassed.

 

[cpaharley2008]

I just checked my 2016 Escape 19 and it appears to have that valve. I did not do anything special last year during winterization but now that I see it, I'm concerned? I flushed the water out and already put antifreeze in the lines via the e-z winterization and bypass.The system is "Charged" and under pressure.
I'm thinking now to open the lower bypass which should push the antifreeze thru the pressure valve and into the water heater. Then I'll just have to flush out the heater a little in the spring.
Anyone else have any ideas to winterize that piece of pex pipe from the bypass to the water heater supply side with the pressure valve?

 

[War Eagle]

... Anyone else have any ideas to winterize that piece of pex pipe from the bypass to the water heater supply side with the pressure valve?

Unless I'm missing something, can't you just loosen that black plastic nut on the Pex from the check valve and let the water drain out of the Pex section there? Maybe use a shallow pan to collect the water or have some paper towels handy to wipe it off the floor. Then be sure to reconnect.

 

[rubicon327]

I'm thinking now to open the lower bypass which should push the antifreeze thru the pressure valve and into the water heater. Then I'll just have to flush out the heater a little in the spring.

That is what I would do. Just cycle the valve quickly and you will push just a small amount of antifreeze through the piping leg and into the water heater. No big deal. Not sure what the cracking pressure is on that check valve, but you will need a little bit of system pressure to open it.

I find it interesting that this check valve was needed. Older trailers don’t have them. Suburban manual specifically states that they don’t recommend check valve on cold water inlet as PT safety relief valve will weep.

 

[paulk-ESC]

First, a strong disclaimer: The procedure below is FOR EDUCATIONAL PURPOSES ONLY and was not written as a set of instructions for you to follow. I have not tested this procedure, and there are likely errors and omissions in it. This procedure was created ONLY for my particular trailer, and yours may be different. I assume no resonsibility if you follow these instructions and something is damaged. I have never been a plumber.

Here is what I plan to do next year when it comes time to winterize my trailer. I designed this to minimize the amount of RV antifreeze required in cases where I didn't have a dump station nearby. I was able to winterize my trailer with a similar procedure using about 1 gallon of RV antifreeze this year.

- park the trailer with the passenger side slightly elevated
- buy 1-2 gallons of pink propylene glycol RV antifreeze that does not contain any ethyl alcohol
- start draining the fresh water tank using the ball valve on the tank
- raise all stabilizers
- use the front jack to make the trailer as close to level as possible (exactly level isn't required)
- turn off the water heater gas switch
- add a piece of gaffer tape over the water heater gas switch
- turn off the water heater electrical switch
- remove the water heater anode [step aside while doing so]
- set bypass valves to NOT bypassed (levers must face AWAY from each other)
- turn on the interior water pump. Keep following the steps below, but turn off the pump after it has been spitting air for 30 seconds through the cold water inlet of the water heater
- open all hot taps
- either replace the anode OR use a nylon brush, dental pick, or copper toothbrush sized brush to clean the existing anode threads
- apply 1.5 wraps of Teflon tape COUNTERCLOCKWISE (when the threaded side of the anode is closest to us) and ONLY on the threads closest to the outside of the tank
- wait until the interior pump can be turned off (when air has been sputtering for 30 seconds), then turn off the pump
- open all cold taps
- wait 30 seconds for the cold water system to drain backwards to the low point via gravity
- close all taps
- turn on the interior pump for 30 seconds, then turn it off. This should push any water in the system out the water heater anode opening
- set bypass valves to bypassed (levers must face TOWARDS each other)
- turn on the water pump
- open and close each tap until air comes out at each one for 30 seconds
- turn off the water pump
- use a nylon brush, dental pick, or copper toothbrush sized brush to clean the water heater's threads
- flush the water heater FOR 15 MINUTES to remove sediment with the water heater cleanout wand
- set bypass valves to NOT bypassed (levers must face AWAY from each other)
- run the pump until there is 30 seconds of air coming out of the water heater anode
- re-insert the water heater anode. Either snug it OR set the torque wrench to 7-8 foot pounds
- if we are somewhere that we can dump, clear the black tank individually, then clear the gray tank individually, then open and leave both black and gray dump valves open
- shake the trailer by pushing it from the side a few times
- wait several hours to allow everything to settle
- verify that the hose between the pump and the first junction inside the fresh water system has air near the junction -> this can be done in my trailer because this hose is clear.
- set bypass valves to bypassed (levers must face TOWARDS each other)
- turn on the pump
- open and close each tap one at a time until air comes out for 30 seconds
- turn off the pump
- shake the trailer again a few times
- lower the front of the trailer as far as it can go
- if we were somewhere that we could dump, close black and gray tank dump valves, and reattach the dumping cap
- close the ball valve on the fresh water tank
- pour 1 gallon of RV antifreeze into the fresh water tank
- remove the sink plug
- remove the shower plug
- turn on the pump
- open and then close each tap until pink RV antifreeze comes out consistently
- turn off the pump
- use squeegee to move RV antifreeze from shower and sink into their traps
- verify that enough RV antifreeze is in the toilet trap, shower drain, and sink drain, and if not then fill them more
- place the sink plug in the sink drain
- place the shower plug in the shower drain
- close the toilet lid

 

[paulk-ESC]

I'm thinking now to open the lower bypass which should push the antifreeze thru the pressure valve and into the water heater. Then I'll just have to flush out the heater a little in the spring.
Anyone else have any ideas to winterize that piece of pex pipe from the bypass to the water heater supply side with the pressure valve?

Supposedly, propylene glycol is 4.5 times more corrosive than water, whatever that means. Perhaps a little isn't too bad though. I'd flush the water heater afterwards in future years.

One source:
Proper Use Of Propylene Glycol

In your current situation, you might consider relieving the pressure by opening a tap while the pump is off, then opening the lower bypass valve to allow water and antifreeze to mix, then re-bypassing it again before you turn on the pump. I think as long as there isn't pressure in the system, that one way valve should prevent antifreeze from entering the water heater until you pressurize it in the spring.

 

[paulk-ESC]

I find it interesting that this check valve was needed. Older trailers don’t have them. Suburban manual specifically states that they don’t recommend check valve on cold water inlet as PT safety relief valve will weep.

I find it interesting too. This is touched on in the thread that I linked to in my first post in that ETI seems to have made this change to resolve the leaking toilet issue. I would much prefer though that the toilet connection be made able to withstand pressures over 150 PSI, since that is the pressure that the pressure relief valve leaks at, but perhaps that isn't feasible for some reason. I don't see a benefit to any of the other sinks and showers as they all need hot water pipes which would still be pressurized to 150 PSI when the water in the water heater expands under higher temperatures.

 

[cpaharley2008]

I sent an email to Reace on Thursday, but they were closed Friday, maybe he can provide some insight next week?

 

[thoer]

I sent an email to Reace on Thursday, but they were closed Friday, maybe he can provide some insight next week?

Good idea.

I am wondering if this has proved to be an actual problem for freezing, or a potential problem. Has anyone confirmed that water is actually being retained in this pipe section by disconnecting it from the hot water heater?

 

[cpaharley2008]

I got to thinking about this water heater pressure valve on the inlet supply side and it dawned on me that any freezing in that supply line from any residual liquid will release the pressure and enter the heater. Exactly opposite of the fresh water line where the water is held captive by the vacuum created, here there is no vacuum as the water heater is empty! So there should not be any freezing issue. Just my thoughts at 6:15 in the am.

 

[War Eagle]

Good idea. I am wondering if this has proved to be an actual problem for freezing, or a potential problem. Has anyone confirmed that water is actually being retained in this pipe section by disconnecting it from the hot water heater?

I blew out the water lines on our 21' last week, but part of my blow-out procedure included blowing out that section of cold water line while the water heater anode was removed and the two valves were set back to the normal water flow position - specifically to blow out that little section of line that is isolated when in bypass mode. Afterward, I disconnected the water line from the check valve, and as expected after the blow-out, there was no water remaining in that section of line.
On another note, I noticed a screw cap on the bottom of our galley sink P-trap. Unscrew the cap, let the water in the P-trap drain into a small container, and wallah, the sink drain is empty and winterized.

 

[cpaharley2008]

Yes, there is one on my 19 also, something new.

 

[paulk-ESC]

There seems to be a lot of confusion as to why I think there would be water in that section of pipe. Let me go step by step to explain why there should logically be water in there.

Let’s start conceptually with a water system that is fully pressurized, and that has water in every pipe and inside the water heater. If your first step in the winterization process is to isolate the water heater by turning the bypass valves, then the water sitting in the pipe that goes from the lower bypass valve to the water heater can’t go back through the bypass valve, since the bypass valve is closed in that direction. The only direction that the water could potentially go is into the water heater, but there is a check valve in that direction now. Check valves have a spring that holds the valve closed unless there is some pressure applied to open the check valve. For more details, here is a post which shows the internals of check valves http://www.escapeforum.org/forums/f9/repairing-the-city-water-check-valve-2864.html . Since the bypass valve has isolated this section of pipe from the pump, even if the pump is later turned on, there is no pressure applied to the water within that section of pipe, therefore the check valve is never opened, and the water has no way to escape.

Later, when that pipe freezes, a little bit of water should go through the check valve as the water in the pipe expands creating pressure in the pipe, however the freezing process tends to start by forming ice at the walls of the pipe before the interior, so the check valve could freeze shut before the water at the interor of the pipe transitions to solid form.

Here is a graph of the density vs temperature of water:
https://qph.ec.quoracdn.net/main-qimg-1fabd774667da19359098da4687526f3

 

[War Eagle]

For those who haven't noticed it, here's a photo of the screw cap drain on the bottom of the galley sink P-trap in our 2017 21'. Easy way to winterize that one.

 

[rubicon327]

For those who haven't noticed it, here's a photo of the screw cap drain on the bottom of the galley sink P-trap in our 2017 21'. Easy way to winterize that one.

Great to point this out. I suspect the use of this screw cap drain goes back many years across all models. We have one on our 2010 19. Just used it the other day when taking apart the plumbing to fix a small leak at the sink drain collar. You should have seen the crud that came out of that trap. The winterizing would double as preventative maintenance to get any of the heavier bits of stuff out that sit in the trap. Probably would never cause a problem, but can't hurt to get it out when winterizing.

 

[cpaharley2008]

Suppose one turns on the pump, opens a spigot, and runs it until the pipes are empty and spitting air? Then isolates the water heater for winterization by turning the valves and fill the water lines with antifreeze via the pump?
Also it would appear that valve is open when there is no pressure, thus when hot water is drawn, the pressure drops and then cold water is allowed to enter?

 

[gmchamplin]

Any answer from Reace yet?

 

[cpaharley2008]

Just got off the phone with Escape, Jeff Busch, parts manager called me back in response to my email. The brass valve is a one way valve to prevent higher pressure escaping the hot water tank and damaging the pump. When you open the water heater pressure valve and remove the anode, any water in that line will siphon out into the water heater, it is one way only to prevent backwash and pressure into the water system from the water heater. So in reality there is no change to the winterization, the water heater anode removal takes care of this valve and any residual liquid left.