Today I discoverd the Seaward water heater on my 2002 Mark II has a slow leak, which had gone on probably for quite some time. Occasionally I would notice a little water in the bilge, but suspected it was a rain water. However this past week, while the boat was on the hard, and I was checking the torque on keel bolts, I happened to run my hand along the underside of the plywood shelf that supports the water heater and two 4D batteries. The underside of the shelf was very wet and severely delaminated. After checking hoses and hose connections for leaks I felt the only source of water had to be the water heater. Today I removed the batteries and water heater and, sure enough, the shelf section supporting the batteries was soaked and badly delaminated. The shelf was so weakened that I feel the batteries would have broken through in a pounding sea.
Right now I am planning on replacing the shelf structure with marine plywood. In the interest of time I will probably buy a Kumma hot water heater with the same dimensions as the Seaward. The WM catalog suggests using a magnesium anode to extend tank life. This sounds like a good idea, but does anyone know how ths anode fits to the tank? Also how best to prevent this from happening again? Would a pan for the heater be practical? Any advice will be appreciated.
Thanks; Bill
Your water pressure pump did not turn off and on occasionally?
Bill,
That's right. Listen to your water pump. It should not cycle on when the water isn't being used. If it comes for a second or two then stops you are loosing water pressure (water) somewhere. Then the search starts.
FYI I had a problem with occational water leak the first season with Shamrock. I tracked it down to the pressure release valve on the water heater. Easy fix.
Jim
Good point, and indeed this spring after dewinterizing I did hear an occasional 'burp' from the water pump, maybe once every hour. Although the boat had been winterized there was still some water in the tank and probably it was seeping out all winter. The tank was leaking out the bottom.
Bill
My water pump looses pressure at it's check valve, leaking back toward the holding tank.
So if the pump cycles every now and then it's not "always" a direct indication you're leaking externally in the system.
I thought hot water tanks already have a sacrificial anode installed, now I have to go look.
Quote from: Indian Falls on May 14, 2013, 08:40:56 AM
I thought hot water tanks already have a sacrificial anode installed, now I have to go look.
The Seaward heaters don't have anodes.
Last season I had to replace my Atlantic Marine hot water heater. I replaced it with a Seaward 6 gallon. It has an option to replace the drain valve with a zinc, which I did. I had difficulty when removing the 1 and 1/16 inch bolt which had about 1/8 inch to grip with a socket, under the sink, at the bottom of the cabinet. This season, I experimented by having a welder attach a 7/8 inch bolt to the 1 and 1/16 inch. It gave me plenty to grip with. It saved my knuckles from getting scraped, and I didn't have to retrieve a lost socket. $20 well spent!
:clap
indian falls, even if your check valve was not "checking" the backflow of the hot water the water must be going somewhere for the system to lose pressure. Unless I am not understanding something?
It goes right back into the pump and if there were enough air space somewhere would push water back to the holding tank. I proved it with a 3' piece of water hose plugged on one end connected to the pump.
It just goes around the internal check valve in the holding tank direction. Soon as the pressure drops on the demand switch it pumps up the hose and leaks back to the pumping section. No water escaped anywhere.
Odd isn't it?
Edited: "holding tank" in this post is of course the "freshwater" holding tank or tanks as it were. I hope we all know that our fresh water pumps are downstream of the freshwater tank...
Bill : The "leakers" on the water heater are generally the water inlet and the water outlet. These fittings are usually nylon and when tightening the hose clamp the tend to become oval and leak - especially the tighter they are tightened!1
The solution is to purchase brass 90 degree fittings (only a few $$) to replace the nylon ones.
Also owners might think about adding an extension with a hose to the bilge on the pressure relief valve. That way when it does it's job (210 degrees and/or 125psi) the water coming out doesn't drip on the heater and it's wooden platform. A few thoughts
Dan, FYI, the holding tank is where the stuff from the head goes. I believe you're referring to the water tank(s). :D
I think I understand now, you are refering to the check valve in the pump. I thought you meant the check valve on the cold water supply installed just prior to the tank.
Before you rip out the hot water tank, check the hose clamps for the galley sink up and behind the hot water tank. They might be the source of your leak.
Bill : As Ken mentioned to check all the hose clamps for the water lines, here's anther thing to check.
The sink drains (MKI) are notorious for leaking on to the top of the water heater - that's why many of us have replaced the sink drain system with
1 1/4" PVC!! Easy to check - put a paper towel and fill the sink then pull the drain plug. Then if the drain is OK just run some water out of the faucet to check the hoses! A few thoughts
Quote from: billandalita on May 14, 2013, 05:22:53 AM
Although the boat had been winterized there was still some water in the tank
This could be the source of your problem. Best to make sure that all water is evacuated. First I drain the tank in the normal way. Then I connect the dinghy pump to the water inlet and blow the remaining water out: another couple of pints come out. This avoids possible problems caused by freezing. Several other owners have experienced the same problem that you have after failing to expel the remaining water before freeze up.
Tony
I did rip out the Hot water tank the other day and also the 5/8 in. thick wooden shelf that supports the water tank and batteries. See the attached photo. Right now I have cut out a marine plywood replacement and will reinstall it Friday with a new KUUMA hot water tank, hopefully with a magnesium anode. Still not sure what caused the leak or exactly where it is, so I will report on that later when I have more time. The freezing of water in the bottom sounds like a possibility since that is where I think the leak is, but still, how could ice rupture anything in the bottom of the tank? Also attached is a photo, (I hope) of the tank's water connections. Note that the hot water exit is about half blocked by what look to be aluminum oxide deposits.
Bill
Oops. I guess I didn't attach this picture of the shelf that holds the hot water tank and batteries. So here it is hopefully.
Bill
Had leakage going down to my board support some time ago. Fortunately
it was the pressure relief vale on the side of the tank. It does drain directly down.
a replacement valve cured the problem
I'll add my vote to the problem being fittings and not the tank itself, especially if your boat is only 10 years old. You can replace most fittings in-place with some cussing and about 4 knuckles, plus maybe $20 of large sockets. Otherwsie, remove the square tank (a geometry puzzle), remove the round aluminum tank from its square galvanized box and inspect everything. I ran a pressure test on my MkII water heater some years back using a hose bib and a garden hose to make sure my new fittings didn't leak. I also cut a notch in the fiberglass locker opening to make reinstallation easier.
Thanks to all the folks that came up with suggestions for my leaking hot water tank. I did purchase a new Kuma tank from West Marine, which is close in size and attachments to the Seaward water heater that came with the boat. I installed an Aqua Pro magnesium anode into the tank's drain port and installed a T-line into the inlet port with a valve to drain the tank when needed. The magnesium anode is 9.5 inches in length, and obviously cannot be replaced until the hot water tank is removed from its location. My plan is to change the anode any time the batteries are removed and the water tank can then be fairly easily accessed. Hopefully the anode will last a few years. I have been checking the old Seaward water tank in my garage ever since. Even under city water pressure there was no obvious leak on the fresh water or the engine coolant side. However there was a constant very slow seepage from the underside of the tank which perhaps left about a teaspoon of water each day in a catch bucket. There is a very small but noticeable corroded spot on the bottom of the tank which is the apparent source of the leak. That slow leak stopped this week; perhaps because it corroded itself shut. Currently I think this very slow but constant leak was the culprit that caused delaminating of the wood shelf holding the tank and batteries.
Guys : One of the most frequent water leakers (beside the In and Out lets is the pressure relief valve itself. (see the Aug 2013 Mainsheet!!)
Take a short piece of 1/2" hose, an adapter and attach it to the Out end of that PR Valve and let the hose drape down into the bilge. To check roll up a piece of paper towel and stick it into the end of the hose. Then check the end of the rolled-up towel and see if it gets wet(need a dry bilge!)!!
My experience is that once a pressure relief valve leaks on an old water heater - just get a new one as the old one will always leak/seep!!
it looks to me that the partial blockage is on the cold inlet and not the hot outlet!!
A few thoughts
I think the orientation of the tank in the photo may be a bit confusing. The photo of the tank is an end view with the base on the right of the photo and the top of the tank is on the left. Thus the partially blocked opening at the bottom of the photo is the hot water outlet. The cold water inlet is at the top of the picture and to the right of the pressure relief valve.
Perhaps of interest are two more photos of the tank. The first one shows the bottom of the tank shortly after it was removed and the fiberglass insulation partially removed. Note the corrosion evident on the base of the tank, evidently caused by rust from the steel container box where it contacted moisture. This was the only source of corrosion I could find at the time. I subsequently applied city water pressure to the hot water side of the tank and then to the engine coolant tubes. There was no leak from these tests. I then filled the tank with water and stood it on its coolant end side for two months. For this entire period as mentioned previously, a very small amount of water collected in an oil pan dish in which the tank set. The second photo shows the tank turned upside down after the leak test of two months, with a small "pinhole" corroded spot on the left and a water mark running down to the bottom of the tank during the test. Hope this was interesting: Bill
Bill, did that leak exhibit itself as an apparent water pump pressure issue?
In my seaward manual it recommends the nylon bushing, which gets brittle and cracks every few years. I hadn't thought about the brass fitting, but it seems to make sense. might want to use Teflon tape? We came back from a short walk checking out the grounds of a new marina when we tied up and water was being pumped out of our normally dry bilge. looked like it just happened. glad I bought two 1/2" elbows the last time it went out, but I think I like the brass idea better. Are they typically the same thread pattern?.
Quote from: Stu Jackson on August 06, 2013, 06:55:35 PM
Bill, did that leak exhibit itself as an apparent water pump pressure issue?
Stu, The water pump was definitely not coming on regularly due to low pressure, except once when I had an obvious hose connection problem. The leak must have been so slow that any pressure loss was undetectable over any reasonable length of time. Bill
aI the only one that winterizes with the rv antifreeze rather than drain?