Hi - I've got a slow leak in my freshwater system - every once and a while the water pump comes on and the bilge is slowly (very slowly) filling with clean water (like an inch a week). I've been able to isolate the problem to the hot water tank. For the time being I've bypassed the hot water tank - connecting the input hose and output hose (the way I would do when winterizing the engine. Leak seems to have stopped.
My question - is it safe to motor with the hot water tank bypassed? I am thinking it is, but I seem to recall something about the raw water which cools the engine coolant also passes through (around?) the hot water tank - that is how I get hot water when motoring I think.
Is it safe to motor with the hot water tank bypassed (well - safe except for the frustration of my wife not having hot water)?
Thanks in advance.
No foul, no harm so long as they are tied together.
That's essential how the engine operates when it comes across the pond. Catalina takes the hose off and connects the WH.
Thanks. So just to be clear - I'll be okay since the input and output hose of the water heater are connected? Its now a closed loop.
Now that I've bypassed the heater, no leaks and no occasional (but brief) running of the pump.
Just want to be sure no problem motoring.
That's correct, NO problem.
Ken is correct when he says the engines came without water heaters.
Why?
'Cuz they were (and are) tractor engines. :clap
I get my Kubota parts from our tractor dealer about 3 km away from our house. :D
Great guys, right parts, fraction of the Universal prices.
Ken also contributed a very good wiki article on the coolant flow, with corrections to the manuals diagrams. You might be interested in checking it out.
Thanks Stu, Ken...
...I'll try and find the wiki article.
I would suggest when you replace your hot water heater install a bypass. Saves a lot of aggravation winterizing and is little added work when you have your water heater out. Here is a link to WM can probably do better someplace else.
https://www.westmarine.com/buy/camco--water-heater-bypass-winterizing-kit--329195
After looking closer I'd buy one with two 3way valves
Jim
Geoff
The article, I think is the 2nd under the engine > cooling topic. I updated some text last night.
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 did an alternate method that assures full flow. (For unrelated reasons) I have my potable connection to the WH inzie/outzie on opposing male/female brass garden hose fittings. I simply unscrew them and screw together the m/fm hose ends. Even quicker would be brass garden hose quick connect fittings. I have great access to the WH (not buried in a cabinet) so my lack of C34 knowledge pontificating applies to if you have decent access somewhere so that you can easily access the hoses (doesn't need to be right at the WH.)
Thanks. Bypassing the heater is pretty easy - I've got easy access to it and simply connect the 'in' and 'out' hose with a male-to-male barb. Takes only a minute or two...so I don't think I need to install something like this...but certainly would if the WH were not so accessible.
I'll have a look at the article.
Ken - read the wiki - thanks - helpful. Next question - even though the water heater is bypassed, it will still get hot while under engine - correct? If so - any risk of it over-heating if there is no water in it?
There's no issue running the system as you proposed. As I have said, no harm no foul.
HOWEVER, DO NOT turn on the shore power to the WH with no water in it. That can burn out the heating element.
Yep - thanks - already thought of that and temporarily disconnected the WH breaker to prevent any accidental turning on.
You can also bypass the water heater hoses at the engine/thermostat hosing by connecting a short piece of hose to the thermostat housing and engine. Picture on the left is my original M25XP showing the water heater hoses connected. Picture on the right is my replacement M25 with the water heater bypassed.
If your water heater is leaking and needs to be replaced then consider replacing those old hoses when you replace the water heater.
Quote from: Hugh17 on August 20, 2019, 02:55:45 AM
>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If your water heater is leaking and needs to be replaced then consider replacing those old hoses when you replace the water heater.
Absolutely, writeup and link in Critical Upgrades.
Quote from: Jim Hardesty on August 15, 2019, 09:22:19 AM
I would suggest when you replace your hot water heater install a bypass. Saves a lot of aggravation winterizing and is little added work when you have your water heater out. Here is a link to WM can probably do better someplace else.
https://www.westmarine.com/buy/camco--water-heater-bypass-winterizing-kit--329195
After looking closer I'd buy one with two 3way valves
Jim
Hi all, I'm re-activating this thread because it's relevant to me. I'm not replacing my water heater, but I am shopping around for bypass kits for my existing heater (which is only about 5 years old), and have a bunch of questions.
- Does the linked Camco kit have the right threads for our heaters?
- Will it fit in the tight confines of the MkII dinette settee? Is there an acceptable workaround with elbow fittings?
- Is it possible to remove the old fittings and replace the new ones without removing the whole tank?
- Is the three-way valve a "full flow" type? If not, can you recommend a valve that is?
- I like the idea of a single three way valve paired with the check valve that's included for the hot water outlet. That simplifies things because you only have to flip one valve. But does this new check valve (in addition to the cold water check valve that's already present) create too much resistance to flow?
- Finally, it appears that I'd have to add some hose barb fittings to attach the existing hoses. I wasn't able to pull apart my system today to measure the ID, but it looks like the hoses are about 3/8" id. Is this correct?
By-pass is really simple. Here is what my by-pass looks like. I also put instructions in plastic on water heater in case someone else was doing it.
Instructions are on water heater as follows.
1. Turn off hot water ac breaker and water pressure dc breaker.
2. Turn cold water in (lower valve) to by-pass
3. Open tank drain
4. Open hot water at sink faucet. So tank will drain
5. To speed up draining use blow on vac or air compressor at sink faucet
6. Let tank drain
7. Turn hot water out (upper valve) to by-pass
8. Done
Jim
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.
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!! :cry4`
My 1st Mate and I found that there is nothing like a nice warm shower just before hitting the Vberth in the evening!! :clap
A thought
Quote from: Ron Hill on November 11, 2019, 02:53:00 PM
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!! :cry4`
My 1st Mate and I found that there is nothing like a nice warm shower just before hitting the Vberth in the evening!! :clap
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.
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?
Quote from: Breakin Away on November 11, 2019, 06:52:05 PM
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?
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.
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.
Quote from: KWKloeber on November 12, 2019, 01:46:54 PM
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.
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
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.)
Quote from: KWKloeber on November 12, 2019, 05:05:14 PM
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".
Quote from: KWKloeber on August 15, 2019, 10:25:25 AM
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.
Quote from: Ron Hill on November 12, 2019, 02:54:09 PM
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.
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.
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
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.
BA
I'll submit that you're using up too many brain cells over something that plumbers have figured out long ago. :D
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.
Quote from: KWKloeber on November 14, 2019, 08:08:32 AM
BA
I'll submit that you're using up too many brain cells over something that plumbers have figured out long ago. :D
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.
If plumbers were doing it, I'd have all copper plumbing.
When Catalina did it, I ended up with a (apparently) hazardously under-spec'ed check valve. That's what's led to burning some brain cells over wondering whether the PVC ball valves in my manifold might also be under-spec'ed. I now see that the PVC ball valves I saw at Home Depot are spec'ed to 150 psi, so presumably the ones in the boat are similar.
I've had one of those "crappy" check valves in my water supply under the galley sink for 32 years on my boat, still works just fine.
I replaced the one under the head sink to the shower sump with an inline Raritan check valve. The shower sump pump, IIRC, is in a different place on the Mark IIs.
I posted pictures of the old and new years ago, I'll see if I can find it.
Quote from: Stu Jackson on November 14, 2019, 09:23:26 AM
I've had one of those "crappy" check valves in my water supply under the galley sink for 32 years on my boat, still works just fine.
Ya, it's presumably only an issue if the WH over pressures, and then (if I understand ShurFlo correctly) it could explode before the T&P safety valve releases. The 100 psi cv will pop before the 150 psi T&P.
They're not crappy, just not meant for the purpose it was installed, then doesn't stand up when it's needed.
Interestingly and related, new residential WH installations/replacements now require an in-line expansion tank to soak up the thermal expansion.
I'm confused. About the system pressure. My domestic water pump is rated for X gpm at about, IIRC, anywhere from 40 to 55 psi. The T&P safety release valve on the water heater appears to be there in case the heater itself has created over temp or over pressure. But if the water system PUMP can only produce a max of say 55 psi, then what's the issue with the old check valve? Sure, if the system clogs up and the pump keeps running, maybe, just maybe, that 55 psi could be exceed AT THE LOCATION of the check valve, but if that's ALL the pump can produce, where is that extra 100 psi coming from?
Stu
We're talking about the cv on the cold water supply to the WH, which prevents backflow from the WH back into the cold water supply lines. It doesn't see excessive pressure unless the WH goes heywire and over pressure (which the T&P safety valve would relieve.) But that model ShurFlo cv is rated lower than the T&P, so it can explode before the T&P ever opens to relieve the pressure.
Per the email ShurFlo said they've "seen it happen" which is why they don't approve that cv for a WH.
Guys : What Ken is talking about in the WH "back flow" prevention valve is "run-a-way" overheating when you are plugged into shore power! :cry4`
A thought
The check valve is checking whether the WH is on AC or heated by the engine. But of course it would explode ONLY if on AC - the engine wouldn't get the WH hot enough to develop the pressure.
The density of water at 100°C is 4% lower than at 20°C. The water in a 6 gallon tank will expand by a quart in volume, putting pressure on hoses, barbs, valves, and pump. How much pressure depends on the elasticity and volume of those peripheral components, virtually all of which will be at ambient temperature because the water isn't flowing.
The density of water at 77°C (engine temperature) is 2.5% lower than at 20°C. The water in a 6 gallon tank will expand by 0.6 quart in volume. That's still significant expansion, and could test the limits of the check valve. Bursting is definitely less likely than using the electric heater, but not sure I'd say it's impossible.
What is the pressure rating of the heat-welded version of the check valve?
Golly, I know exactly what check valve we're talking about.
One option is that if, as ba says, things start goin' south and pressure really builds, when the check valve goes, it could go along with the "...hoses, barbs, valves, and pump..." IIRC, most pumps have check valves on the outlet, too.
By then, one could/would have bigger issues than an old check valve. Which on my boat has been working for 32 years.
Of course there are better valves, and incremental improvements and enhancements are always welcomed. I'm just suggesting we put this in proportion.
Your boat, your choice. :D
Nothing like a heated discussion about hot water to get the pot boiling! 8)
I don't think that age of the check valve is a negative here. Ken said that the older ones bolted together and were pressure rated. At some point Shurflo changed the design to a heat-welded one. Not sure when that change was made, but your 32 year old one might be better than the newer ones. Does yours bolt together, and allow disassembly to clean the flapper?
BA
My '84 had the square, bolted version, and in 2005 I bought the new version for a different purpose. When ShurFlo made the change - I dunno?
I believe the current style cv is rated @ 100 psi.
Presumably, the fittings are rated at least as high as the T&P safety valve? I dunno.
The nylon barbed fittings I've used are rated 150 to 200 psi.
The cv rating is an issue only when it becomes an issue -- do we ignore a weak point? I guess I just have a preventive attitude. To me, my not addressing it and buying the metal cv -- would be like replacing a leaky T&P with a plug. Hell, the T&P hasn't blown in all these years so why should I spend the extra money to replace it? I only need a safety factor when I NEED it, and I can't predict when. My luck is less than stellar but I wouldn't run out tomorrow and change the cv -- but why not add it to the to-do list just to have the additional insurance?
Quote from: Breakin Away on November 14, 2019, 05:12:39 PM
I don't think that age of the check valve is a negative here. Ken said that the older ones bolted together and were pressure rated. At some point Shurflo changed the design to a heat-welded one. Not sure when that change was made, but your 32 year old one might be better than the newer ones. Does yours bolt together, and allow disassembly to clean the flapper?
Here's the pictures, should answer your question, too.
https://c34.org/bbs/index.php/topic,4114.msg33528.html#msg33528
That old bolt together ShurFlo was rated for WH use and was OEM on my '84.
Raritan specifically states re its RCV valve:
"Not for use on pressurized lines."
All of the check valves on my 1990 are the original bolt together ones and no issues (so far).
Quote from: KWKloeber on November 15, 2019, 05:26:05 PM
That old bolt together ShurFlo was rated for WH use and was OEM on my '84.
Raritan specifically states re its RCV valve:
"Not for use on pressurized lines."
I installed the Raritan check valve on my shower sump line. Just like the post says. That line is under suction.
The only point of my posting the pictures was to answer ba's question about the looks of the two different valves, and what my remaining heater valve is.