Anyone recognize this water heater?

I have to replace the water heater in my 1978 36' Universal Trawler; however, it's so rusted out I can't find any information about it. Seems about the size of a 5 gallon bucket but a little slimmer and longer so I'm guess it's a 6 gallon. My surveyor wrote that it was an 11 gallon but frankly given the size I don't think that's physically possible. I was hoping someone here might recognize it. Pics below.

I was thinking of replacing it with a 6 gallon Kuuma as I don't see anything available new today that looks like a direct replacement so I'll have to re-plumb things a bit no matter what I get.

You can calculate the volume of the tank by measuring the radius of the top and the height of the tank. Then multiply pi times the radius squared. This will give you the area of the top. Multiply that number by the height of the tank. This will be the volume of the tank approximately in cubic inches. Divide that number by 231 which will be the number of gallons. Now that is the volume of the outer casing but it will be close to what the tank is. Good luck.

**** me, lmao; I'm a computer programmer and I didn't have my work hat on, didn't even occur to me to math it out. Running the numbers from roughly what I recall the dimensions were (I'm not at the marina now) seems it likely is an 11 gallon.

However, part of the reason for asking if anyone knows the make/model from just looking at it, would be to see if I could find a direct replacement somewhere and not have to re-plumb everything. I have no idea if it's original equipment or a previous owner upgrade. These old Taiwan boats don't come with an owners manual.

Isn’t isotherm about the only mfg that makes cylindrical heaters that lay on their side like that? At that apparent age however...direct replacement may be a stretch.

Yea, seems to me that is the case, they're the only cylindrical ones I see anywhere now. Oh well, plumbing it is, part of the fun of and old boat; doing **** yourself.

Try Torrid. They are in the Seattle area, so send them a picture.

Considering the age you're going to have to do some replumbing anyway so get the best you can. Isotherms are well thought of and can mount on their side like that so may fit the space better. I have a model with the poly outside shell and stainless tank. It's very nice.

Ken

https://www.practical-sailor.com/issues/25_3/features/4220-1.html


Allcraft has the shape you want.

Thanks for all the input guys; I just ended up installing a Kuuma 11 gallon and re-plumbing the copper to fit the new locations.