You can get hot/cold from a residential water heater if the dip tube (cold water delivery tube) is corroded off. Does this model have a dip tube??
Les
Les
356 Water Heater Fluctuates Hot and Cold
- Thread starter CharlieSea
- Start date
If it's not a mixer problem on just one faucet, the problem is prob'ly in the water heater. Cold water comes into the bottom of all of 'em--either an inlet fitting at the bottom of the tank or a diptube--and the hot water discharges out the top of the tank...it literally overflows out the discharge when the hot water side of a faucet is opened. The boat's fresh water pump keeps the tank full so it can do that. So if it's happening on more than one faucet, I'd have a chat with the water heater mfr.
I will go on a limb here. Is it possible that you have the in and out of the water heater mixed up?
It that scenario, when the pump is not supplying new cold water, the water would mix to have more or less even temperature (hot), but the very moment the cold water is added (from the top) it sinks to the bottom and spills to the hose leading to the faucet.
It that scenario, when the pump is not supplying new cold water, the water would mix to have more or less even temperature (hot), but the very moment the cold water is added (from the top) it sinks to the bottom and spills to the hose leading to the faucet.
I'd agree with Peggy but he changed the water heater to no effect - even a different brand! On the 356, the water lines are color coded - as Peggy said, the blue line (cold) goes to the lower fitting; the red (hot) is the upper.
Ok, everyone who said manifold is probably correct. I spoke with a guy from Sea Tech. They no longer build that manifold but he says the divider between the cold and hot is a gasket or something and absolutely suspect. I'll take it apart tomorrow. Has anyone opened one up. After eliminating the heater, it seems logical. Thanks to everyone that took an interest.
If you said manifold then next time you are in Miami, I'll buy you a beer. Not to bad to take out, about 20 minutes. The thing with the star shaped hole is supposed to separate the cold from the hot. The fix was a 1/8" thick aluminum disk that would fit where the old divider was. The flanges of the push in fittings left and right though petty thin hold it in place. A little Dow Corning 733 (they said it's food safe) takes up the little slack (1/4" too thick , 1/8" a bit thin and no 3/16" available). Put it all together and voila constant hot water. Guess, the high water temperature on the plastic and the constant pressure broke the plastic piece; the aluminum should hold. Wow! Thanks for all the interest. Can't wait to enjoy the hot water. See pictures.
Attachments
One last thought, will the aluminum transfer the heat from the hot side to the cold. 'Have to wait and see. Here's the look down the tube broken.
Attachments
Wow! it looks just like a joker valve - that explains the fluctuations.......
Thanks for letting us know - something to watch for!
BTW, my personal 356 hot water mystery was a drop in shower pressure and occasional pump cycling; after going nuts trying to find the problem finally found it - the hot water line to the shower goes from the manifold across the boat under the sole, turns aft at the outboard side of the nav station, goes under the sink area and the head area then up the the shower faucet. at some point, the hose wedged itself into a vee shaped gap between the hull and the bulkhead bottom (shame on you, Hunter) and abraded a hole in the tube. If the boat motion caused it to wedge tightly in the vee, no leak; if it was loose,leaks! only found it by using a remote camera to folow the line - too far under to reach or see otherwise
Thanks for letting us know - something to watch for!
BTW, my personal 356 hot water mystery was a drop in shower pressure and occasional pump cycling; after going nuts trying to find the problem finally found it - the hot water line to the shower goes from the manifold across the boat under the sole, turns aft at the outboard side of the nav station, goes under the sink area and the head area then up the the shower faucet. at some point, the hose wedged itself into a vee shaped gap between the hull and the bulkhead bottom (shame on you, Hunter) and abraded a hole in the tube. If the boat motion caused it to wedge tightly in the vee, no leak; if it was loose,leaks! only found it by using a remote camera to folow the line - too far under to reach or see otherwise
Good show Chuck. There is nothing harder to trace than an intermittent problem. 'Never had luck trying to use one of those remote cameras. What is surprising is that there aren't more 356's out there with the same problems; 500 units plus however-many 36's is a bunch of boats. I wonder why the plastic failed.
This is just a wild guess but it sounds like there could be some debris in the hot water line from the tank to the manifold if the problem is in all the fixtures. Some calcium broken off from inside the pipe may be plugging the manifold and when the pressure is changed, is dancing around inside the pipe, partially blocking hot water flow. I would disconnect the hot water line coming from the HWH to the manifold, run it with the pump on, and see if the temperature is constant. That should flush out any debris in that line. Recheck the fixtures, and just check each line start to finish. Seems to me the problem is in the piping or connections somewhere and you need to disconnect upstream and test until you are sure there is no blockage.
Hi CharlieSea,
yeah, it was a real pain - could see the water coming out with the camera but it took a friend with really long arms to reach under the sole and pinpoint the issue. the jamcleat shaped opening where the hose wedged had a sharp, jagged edge on the bottom of the bulkhead that acted like a sawblade on the tube. funny thing is I hooked the new tube to the old one and pulled it through under the sole, and I made the turn about two feet tighter -- plenty of room to avoid the tight spot.
yeah, it was a real pain - could see the water coming out with the camera but it took a friend with really long arms to reach under the sole and pinpoint the issue. the jamcleat shaped opening where the hose wedged had a sharp, jagged edge on the bottom of the bulkhead that acted like a sawblade on the tube. funny thing is I hooked the new tube to the old one and pulled it through under the sole, and I made the turn about two feet tighter -- plenty of room to avoid the tight spot.