Water heater for 1980 42 post

I replaced the heater in my 1982 42' with a 20 gal raritan 115v water heater.

It was a similar size to the one that was in the boat when I purchased it 5 years ago. The one in the boat was rusted out and was leaking. It seemed to be a similar tank to what you would see in a mobile home or small apartment. It wasn't necessarily "marine grade". I don't know if it was original to the boat or not.

In retrospect, a 20 gal was probably overkill but I got a good deal on a scratch and dent model. A 12 gallon model is probably adequate.

You may want to check the functionality of yourheater before going through the trouble and expense of replacing it. The previous owner had a bypass hose for the hot water tank that was used when winterizing the boat. It allowed you to drain the tank but still flush the fresh water system with pink antifreeze; saving the expense of running 20+gal of pink stuff through the hot water pipes.

That was a good point made by Rover 1 about the bypass reason. You said your heater drew current on the survey so chances are if you reconnect your heater to your system she may be all good.
If you do replace the heater, I would recommend using a marine grade heater that has a stainless steel inner liner. Make sure you can change the actual heater element without tearing the whole boat apart to get to it.

Another option is to replace the heater with a small instant on unit about the size of a brief case and reclaim all the space that the existing heater uses. You already have to have shore/genset power to heat the water and you never know when its going to kick on. The only disadvantage is you don't have the holding tank to store warm water.

Agree on the bypass being used for winterization. I do the same thing. So it may still work OK. I replaced mine 2 years ago with an 11 gallon Seaward. Haven't run out of hot water unless we take 3 showers right after each other. If you have to replace, make sure you measure how much room you have between the engine and generator. I had to take the Seaward apart. The inner tank just fit through then put the outer skin back on. Not a big deal. If any bigger, I would have had to remove engine cooling pipes, drain engine coolant, etc. Your engines may be slightly different config than my 84's.

Good point about get the the old heater out and the new heater in. For my 20 gal raritan, I had to temporarily remove the 4x4 wood support that holds the salon floor to give myself enough room too remove and replace the heater. I used a bottle jack to support the floor a little forward of the original support. I unscrewed the support but also needed to used a sawzall to cut through the adhesive used to bond the wood to the stringer. I used some liquid nail framing caulk when reinserting the support then reused the screws. Looks like factory!!

That's great. What type of unit did you put back in?

I'm new to the forum and I have a 1982 42' Post. I put in a 6 gallon water heater, I believe a Force. It's in a stainless steel box. I've found 6 gallons to be plenty because I've always turned the water off while soaping. With quick recovery, I've never run out, even when people take showers one after the other.