Need opinions on gas hot water heaters

We have been getting an odd smell from our just cleaned in the dishwasher dishes.
It smelled swampy and we figured out the problem was with a gasket and we cleaned and replaced it.
The majority of the odor is gone but I still pick up a faint odor that is off.
Is it possible this is from the hot water heater? Hope so because otherwise we are stumped.

I am waiting for the plumber to arrive to look at the job.
Interestingly 65 gallon tanks are no longer made!
The choices are a 50 or a 75 gallon. So guess we will go with the 50 gallon.
I challenged the plumber on the phone but then checked with a big company here. So will
need to apologize to him.

Does anyone else have a tankless? Our tank is getting pretty old and it doesn’t look like a new one will fit in the old space. Looking at alternatives. I only have about 19" square to work in.

I would be curious to know others experiences with Tankless units, especially if they live in a cold zone (I live in northern NJ). My current hot water heater is okay, it is 60 gallons, has some life in it, but we have a whirlpool tub that the hot water heater doesn’t work well with (yes, I upped the water temp on it, which helped). Anyway, I thought of getting a tankless unit, but have been told that they don’t work well in colder climates. Others have said as long as the unit has enough capacity to heat water quickly, that it works fine. Thoughts?

Posting blindly here as I haven’t read the previous comments… Another good brand for gas water heaters (tankless) is Rinnai. Ours is made in Japan and works very well.

Typically, the performance of tankless heaters is measured in “temperature rise” or “delta t” (among other factors, but in this case, temp rise is what’s important if you are in a cold climate), which is largely a function of flow rate. If you live in a very cold area, you will need a water heater that has a higher temperature rise number.

Typically, gas tankless heaters have a higher temp rise than the electric ones, and are able to maintain that rise with a higher flow rate, but they are also slightly less efficient. We opted for gas primarily because it is just far cheaper to run than electric here in California.