3-way heater bypass valve replacement

[roscott]

Has anyone had to replace one of these (see pics). Got caught up in the Texas freeze, lost power and all that good stuff. Needless to say, this valve broke. I've ordered a replacement but not sure if I need the special 'pex' tool to replace or does it simply use the pressure from being 'screwed' on to make a water-tight seal. Any advice is appreciated.

[chin_k]

I think the valve itself can be replaced without any tool, assume that the PEX pipe is not cracked or damaged. If any of the tubing needs replacement, you will need the PEX crimper.

[BobW9]

This Flair-It type of valve will screw on water tight, it works well.

*** Make sure you bought the correct new valve ***
The old one on your tank has the valve knob with the airgap, the one in your lower picture from some website has a solid knob and looks to me like the 16914 drain valve.
You want: 16910 Flair-It Supply Fresh Water By-Pass Valve Water Heater By-Pass
Not: 16914 Flair-It 180 Degree Center Drain Valve (this allows water flow a-b 90-degree angle, a-c straight through, 3-way open), it is the one with the 2-piece handle. You might be able to use this one if you're careful to never turn it to the 3-way setting, but it kind of invites making mistakes.

When you have the old one off, look into it as you turn the valve and see how it opens up inside (you can see when it goes from one side to the other). and verify that the new valve has the same openings for the same valve setting (left, right, center).
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1) Unscrew the end caps and pull them out of the way, down the tubing.
2) Heat up the tubing end over the valve's barbs to loosen it (PEX expands and becomes more flexible as it gets warmer). Not hot, just warm should be fine (heat gun, hair dryer).
3) Carefully pull the valve out of the tubing. If its too hard, just heat it a bit more (warm, not too hot!).
4) Repeat 2 & 3 for the other side.

Do not try to pull the old caps off the tubing. The end of the tubing that went over the valve's barbed end will have expanded a bit and will not go all the way down again - even if you can pull the old cap off, you may not be able to get the new cap back on. It is far easier to reuse the caps, since you're getting the same valve as a replacement.

5) Slide the tubing on one side over the barbed end of the new valve. If it is too tight to get on, you can just warm it up a bit again until it slides all the way on the barb.
6) do the other side.
7) Wait 10-15 minutes to let the tubing cool down and tighten up by itself. Then screw on the caps on each side. It doesn't have to be massively tight - I just hand-tighten. Maybe use a wrench to turn it just a tiny fraction more if you want.

Bob

[roscott]

Thanks Bob. I'll double-check the valve type and really appreciate the detail in your post.

[roscott]

Just double checked my order. I neglected to mention I ordered 2 of the valves from the website since I wasn't sure which one I needed. Turns out I ordered both the 6910 and the 6914, so I should be good...assuming I don't get them mixed up.

[BobW9]

Just pay attention to the handles and you'll be good.

Never hurts to have a few spares. The 6914 Flair-It 180 Degree Center Drain Valve is used coming out of the fresh water tank for draining it, at least in my Concourse (though the tubing there is so short and tight that the only way I was able to replace it was to pull apart most of the tubing and connections in that entire area, including the PEX ring connection to the tank itself, which forced me to buy one of those tools to put a new ring back on after - total pain).

[chin_k]

Just pay attention to the handles and you'll be good.

Never hurts to have a few spares. The 6914 Flair-It 180 Degree Center Drain Valve is used coming out of the fresh water tank for draining it, at least in my Concourse (though the tubing there is so short and tight that the only way I was able to replace it was to pull apart most of the tubing and connections in that entire area, including the PEX ring connection to the tank itself, which forced me to buy one of those tools to put a new ring back on after - total pain).

Now I know who to beg to borrow the crimp tool if I need to work on PEX.

[Roly]

I used Sharkbite PEX fittings successfully in my house. They're not cheap, but reusable. Home Depot has an equivalent that is a little cheaper.

Roly

[Jlfchinook]

The wrench is called a flare it tool, about $10.00 to $15.00 deplending where you get it. Not required to change valve, but they work real well in tight area where you can’t get plyers. It is used to tighten fittings not to crimp tubing.

[roscott]

Problem 1 resolved. Valve installed. Bob, your advice was invaluable and made short work of what otherwise, I'm certain, would have been a headache.

However, after turning on the pump, problem 2 appeared. Apparently the back flow prevention for the city water hook up froze/cracked/broke and water started shooting out of the inlet. Anyone know the part number for that (have not yet done a search for one)? I assume the short tube that connects the pex to the city inlet hosts the back-flow as I took apart the shelving under the sink in order to get a good view of everything and didn't see any back-flow inline....unless it is on the pump. FYI....I hate plumbing.