Water Heater Question

[Breakin Away]

Thanks for the suggestions, and the great pics. I'm going to have to look over this design carefully. Unfortunately, I have a more cramped space because your tubing at the top of your first picture is right where PO installed a charger/inverter. I'm going to figure out whether I can add some elbows to maneuver around it.

[Ron Hill]

Guys : Hard for me to understand why someone would want to bypass the WH except for an emergency!!
If you have ever done extensive sailing in a boat that does NOT have a water heater, it is a "Luxury" to have a C34 with a WH. 
Screwing around with a "Sun Shower" Blatter is a real pain or having to get used to a COLD shower is even worse!! 

My 1st Mate and I found that there is nothing like a nice warm shower just before hitting the Vberth in the evening!! 

A thought

[Breakin Away]

Guys : Hard for me to understand why someone would want to bypass the WH except for an emergency!!
If you have ever done extensive sailing in a boat that does NOT have a water heater, it is a "Luxury" to have a C34 with a WH. 
Screwing around with a "Sun Shower" Blatter is a real pain or having to get used to a COLD shower is even worse!! 

My 1st Mate and I found that there is nothing like a nice warm shower just before hitting the Vberth in the evening!! 

A thought

Looks like you don't understand the context here. Winterizing the potable water system is much faster, and requires much less antifreeze, if you bypass the heater. Then you un-bypass it during the season

Also, OP needed to bypass his due to a leak.

[Breakin Away]

I ordered the Camco 2-valve bypass kit from Amazon, so I may have additional questions after it comes in. In the meantime, here's my WTF moment from today. What's wrong with this picture?

[Stu Jackson]

I ordered the Camco 2-valve bypass kit from Amazon, so I may have additional questions after it comes in. In the meantime, here's my WTF moment from today. What's wrong with this picture?

Dunno, could that simply be the check valve?

[Breakin Away]

Yes, that is the check valve. I am trying to remove the hose from it, but finding it rather difficult. Look closely at the picture and you will see why.

[KWKloeber]

Just a heads up that (I've posted it before), according to an email from ShurFlo that CV is NOT supposed to be used on a WH.
It can explode.
There's an older version black ShurFlo CV with the halves bolted together ( not plastic welded ) that was approved for WH use.

[Breakin Away]

Just a heads up that (I've posted it before), according to an email from ShurFlo that CV is NOT supposed to be used on a WH.
It can explode.
There's an older version black ShurFlo CV with the halves bolted together ( not plastic welded ) that was approved for WH use.

Sorry, I haven't seen that email from ShurFlo.

I assume that CV means check valve. WTF? Isn't a check valve installed on EVERY Catalina 34? It's in the plumbing schematic. Isn't it in a few million RVs in the world? It's pretty standard to prevent hot water from siphoning into the cold water via Venturi/Bernoulli effect.

Could they, perhaps, have said not to put one on the hot water side, but the cold water side is OK?

As for yesterday's WTF moment, here's a closeup of my picture. I had to cut a wrench down to make it small enough to get to the hose clamp screw. Clearly this installation was done without any thought to how it might need to be taken apart for winterization.

[Ron Hill]

Breaking : It takes me less than 15 minutes to winterize the WH - rather than screwing around with new plumbing!! 

As Stu says "your boat- your choice" !!

A thought

[KWKloeber]

BA,

It's not that a CV doesn't belong there - it does (on the cold water supply to the WH.) It's simply that THAT particular CV isn't (according to ShurFlo) designed to withstand the pressure that could develop.

Jabsco makes an RV/marine Cv that is approved for WH use.

I bought a SharkBite hot water Cv (home depot online) to adapt to the 1/2" hose.

Be sure to get a bypass that doesn't restrict the flow. Many do.
I had posted earlier this year about that (with pcs.)

[Breakin Away]

BA,

It's not that a CV doesn't belong there - it does (on the cold water supply to the WH.) It's simply that THAT particular CV isn't (according to ShurFlo) designed to withstand the pressure that could develop.

Jabsco makes an RV/marine Cv that is approved for WH use.

I bought a SharkBite hot water Cv (home depot online) to adapt to the 1/2" hose.

Be sure to get a bypass that doesn't restrict the flow. Many do.
I had posted earlier this year about that (with pcs.)

Hi Ken, thanks for the clarification, and especially for pointing out the hazardous check valve. You are right, I misinterpreted your post to mean that check valves in general were not permitted. I'm a little surprised because the check valve in my picture was apparently installed by Catalina. I went through PO's service records and the heater and associated plumbing have not been replaced. Is there a history of Catalina putting in a sub-par CV? Maybe something that should be in the "Do this or else" topics for MkII vintage boats? I'll plan on replacing the CV that's in there while I'm "screwing around with new plumbing".

The camco kits Jim shows can be had from a discount RV place for about half the floating RV sources. 
One consideration is to make sure you're getting a full flow ball valve.  See pic for what you DON'T want.

I couldn't tell from your picture what brand/model of undesirable valve you were showing, but since you recommended the Camco kit that Jim had in his picture, I ordered that. I found it at Amazon for under $12, so it's no great loss. It still hasn't shipped yet, so I could cancel it if I move quickly. Let me know if I should do that.

Breaking : It takes me less than 15 minutes to winterize the WH - rather than screwing around with new plumbing!! 

As Stu says "your boat- your choice" !!

A thought

I'm very happy for you. Some of us have our heaters in different locations and/or different aftermarket accessories that restrict easy access to the plumbing. You can see in my picture that one of the struggles that has slowed me down greatly is a hose clamp that was installed upside down, making it virtually impossible to release without significant reconfiguration. After all this hassle, my choice for my boat is to follow Mainesail's advice and install a bypass.

[Breakin Away]

Ken, I've had a chance now to look over some of the prior posts about the Shurflo check valve. I'm a little curious about a couple of things.

First, I'm puzzled about just how a 100-150 psi pressure could build up in the heater. As an engineer, I'm sure that you realize that 212°F water has a vapor pressure of 14.7 psi, by definition. Ignoring that, are the little plastic hose barbs rated for 100-150 psi? If not, wouldn't that blow first due to the pressure coming out the hot water outlet (which does not have a check valve) and propagating through the whole system? Are the pump and its fittings rated for such pressures? By the way, it looks like the heater hose that WM sells is rated for 250 psi, but it's only rated for up to 150F. Go figure...

Jim's very nice picture shows a white plastic coupler on his hot water outlet. Is that just a F-F NPT coupler, or could it perhaps have a pressure regulator built in, which would render the CV safe for use? I have similar couplers on both cold and hot water sides, but can't get eyeballs at the right angle to see whether they are actually pressure regulators. If not, could I possibly replace them with pressure regulators, which could protect all the barbs, water pump, etc. against the effects of high pressure?

Finally, I thought I'd mention that I have to return the bypass kit to Amazon. It was from Amazon Warehouse, which I've used for a couple years to score great deals on "used" items that were merely in blemished packaging. This time they were really used, and the valve internals had a dark oily residue. (gross!) It appears that the original purchaser used it for oil extraction or some other toxic application, then returned it. I think it's nearly criminal for Amazon to resell something like that for potable water use. Long story short: I'm open to your suggestions for a model of valve that has low resistance to flow. Frankly, I'd love to find a four-way criss-cross (or "x port") valve that could accomplish the bypass in one device, if a small, affordable version exists in plastic or other low-cost safe material.

[KWKloeber]

ba

You have (some) good questions - I don't design the valves or any fittings so, unfortunately, you're asking the wrong source.  You might want to contact ShurFlo on the CV or Seaward (Whale) for the WH.

I didn't recommend the Camco kit -- in the context of the original message, I simply pointed to a reasonable-cost seller of the kit that he found at West Marine.  I don't have a bypass (I do not need one as I use a different set up.)

I see no reason why you couldn't buy quality ball valves and make your own (available space may be a limitation.)  But, you don't need to necessarily locate the bypass at the tank (so long as the hoses/WH will still drain.)

Was the Camco kit suitable or restricted flow?

CTY has never installed anything sub-standard (like PVC fittings below the waterline?; or on my boat, a npt threaded, schedule 40, PVC cap on the straight-thread thru hull [on the unused head waste direct discharge]?) 
In defense, I doubt that anyone knew that the ShurFlo cv is not rated for WH use.



Sent: Tue Feb 7, 2012
To: Ken Kloeber
Subject: RE: Shurflow check valve

I understood, water heaters always have thermal expansion our check valve is not designed to withstand the water heater's thermal expansion. The check valve will break in half I have seen it.

Pedro Silva
Shurflo Customer Service

[Breakin Away]

The Camco valves were very similar to your picture. They were not true ball valves, but more like a rotating gate that appeared to create a constriction to flow with the valve in any position. Not sure if it would be significant restriction, but for that and other reasons I'm working on my own design. PVC ball valves can be gotten for around $2.50, and though they're not 2-way or 3-way, I can buy a bunch and configure to my liking if I can find space for them. I'm waiting until next week when I'll be in Wisconsin, since Menard's will have a lot more options than I can find around here at Home Depot or Lowes.

OK, I can see that in a fully closed system with no air pockets, the water's thermal expansion could create huge pressures in theory. But since the hot water outlet has no check valve, I'd think that a simple pressure regulator (less than the WH's pressure relief) could reduce a lot of headaches. I'll do some research on that, but probably just replace the CV. Even with a new pressure-rated CV and 250 psi rated fiber-reinforced vinyl, I'd still be concerned with the pressure rating of the PVC ball valves used in the potable water tank manifold and all the plastic hose barb fittings. The whole system is only as strong as its weakest link.

[KWKloeber]

BA

I'll submit that you're using up too many brain cells over something that plumbers have figured out long ago.   
The WH has a temperature & pressure relief valve set at 150 psi. The shark bite cv is 200 psi and if you use 1/2" copper stubs you can warm/expand the pvc water hose to fit over them.