Hot water heater recommendation - 28TE

[Nancy]

I'm posting proactively. All we really need right now is a new T&P relief valve (water is being released when under way, but not at the dock), but the old one won't budge, so who knows where this will lead.

Current hot water heater is 6 gal. cylindrical no-name. Documentation isn't in front of me, but I think it's Sure-Stor. If we have to replace it, what do you recommend? I see that prices vary dramatically. Raritan seems high. Is that because of steel construction vs. aluminum? I definitely want a heater that works on 110V and has engine heat.

I'd welcome input on a replacement unit.

[Russell]

Nancy, I had this same problem on my previous boat and changed the pressure relief valve which did no good. The problem is that when running the engine the water gets hotter than the temperature that the relief valve is set to open, so it does. I ended up putting a hose on the relief valve to run the water into the bilge instead of on the shelf where the batteries and bilge pump were located. You might be able to partially close the valve that allows the antifreeze to circulate to the water heater so it does not get so hot when you take a long cruise.

[Nancy]

Hi Russ -

We don't have just a little water escaping - it's a river!

hot water heater-3-06.24.16-1600.JPG

This problem only started in the past week . . . at least to this extent. I noticed it because after running the boat, the water pump was cycling frequently. I opened the center hatch, and it really did look like a river running into the bilge. Releasing the valve stopped the flow, and of course the problem stopped when the engine cooled down.

I suppose this problem could have been occurring for quite some time, but definitely not to this extent. The reason I say it could have been happening is that we've had a small amount of water running into the bilge from under the equipment platform, but hadn't identified the source. But the water pump has never cycled inexplicably before this.

I have the manual for the hot water heater, and it specs a T&P valve with temp rating 140-160. That doesn't make a lot of sense considering that the engine runs at 180.

We're puzzled.

[Tree]

Nancy. I had the exact same problem. The pressure valve on the tank was overrated in my opinion at 10 bar anyway. Personally I'd think the tank would have gone before it released. I've changed mine to a 6 bar, the same type you would find on a household boiler and everything now works fine. Cost was about £10 ($14?).

[Nancy]

Tree, I'm confused. Or maybe I don't understand how the valves work. How did going to a valve that's rated for less pressure resolve the problem? I would think that if the valve released at 10 bars, it would also release at 6 bars even more readily.

[Tree]

That was exactly my first thought but the valve that was already installed in mine would never have opened if the tank was to reach the pressure it was intended for. I've got a thread on here somewhere and between us we did the calculation and decided that the valve fitted originally to the tank was never going to work - the tank being aluminium would have gone first for sure! Now the new valve I have in place works perfectly and under normal use of heating using both shore power and heating from the engine never has opened yet but being a lower pressure valve, it gives me the security that if it did get so hot it would purge and release the pressure.

I think my thread had the word calorifier in it.

[Nancy]

I found your Calorifier thread, Lee - viewtopic.php?f=7&t=6770&p=40236&hilit= ... ier#p40236. I'm still having trouble getting a clear understanding, but it will all be moot anyway if we can't get the valve off.

[Tree]

Nancy, the valve just unscrews. If you've got an aluminium tank just take care as you may have some galvanic corrosion between the brass valve and the aluminium tank. Mine came out surprisingly easy and even being 6'4" I was able to get in the hole under the deck to do it

[Nancy]

The valve won't budge even with an extension on the pipe wrench, which is where this thread started. Mechanic will give it a try in the next few days. He sometimes has a magic touch.

[Russell]

My guess is that this has been going on for a long time and corrosion has started keeping the valve from closing after it cools down. You might try opening the valve by hand a flushing out any particles that might be present. I was lucky like Tree in that the old one unscrewed easier than I thought. My fear was breaking the tank trying to remove the valve and making a small problem into a major one. Your mechanic might be able to take care of it. Good luck.

[Tree]

Obviously try this with caution, but have you tried removing the valve while the tank is hot? The aluminium should expand and since it is a tapered thread going in to it, once you do get it going it will come easily.

[Nepidae]

The ONLY way to go is with a Raritan, period.
Great products and support.
Could go into greater detail except on a cruise using my tablet.
Check out Defender and Boatersland for pricing.

[Nancy]

Charles, thanks for the suggestion.

To all - our mechanic was not able to remove the T&P valve either. Next step is to remove the tank from the bilge, but the batteries have to come out first. We've decided to work on this in the fall or spring. That's because we found a workaround: if the fresh water pump is turned off while underway, the valve doesn't release water. This is acceptable for now.

When we pull the tank, we'll decide whether to replace it as long as it's out of the boat.

[Sisu22]

Did you ever end up pulling the tank?

[Nancy]

I'm over a year late finishing this story. Thanks for rattling my cage.

No, we didn't have to pull the tank. Within two weeks of my last post, the problem began getting worse: we couldn't turn on the water pump until the engine temp dropped to 150 without the valve leaking. We became concerned that the valve was going to fail completely, so we decided to fix the problem mid-season.

Our mechanic's #1 guy decided to try the valve removal again. He was able to move the batteries a little out of the way and got a 4' pipe wrench on it. If the valve broke, we had nothing to lose as we were going to replace the tank anyway. But the valve came loose, he put on a new one, and it's been good since then.