I believe those are bug wounds. maybe spidermites.
Sorry you're having so many problems. have you checked the EC of your tap water ?(right out of the faucet)If it is softened, it should have a measurable EC.

The EC of my tap differs with the temp. Hot water has a very high reading of over 2. I dunno if this is normal or not. Cold water is around .7

I went and looked under the affected leaves but could not discern any insects. I don't have a magnifying glass (never need one till now).
I did find a small weird looking gnat (I think it's a fungus gnat) on the under side of a yellowing leaf...stuck to the leaf. It looked like it was attached. I tried to take a photo but my camera won't pick it up. Next to it were fresh wounds on the underside of the leaf. I didn't think gnats attacked plants like this. It probably came from the plants I set outdoors during the summer then bring in during the Winter. Now what do I do?

Since your bean's leaf margins are in tact, I would suspect insects are to blame as has been mentioned. That aside, there are several other things that need clearing up here.

First off, I'm a plumbing contractor with 44 years experience. If you are using "softened" water, it is being flushed through a brine tank that has been back-washed with either sodium chloride or potassium chloride. Neither is any good for a plant; each will KILL your plants.

A reverse-osmosis device will NOT remove these salts. Use plain, unsoftened tap water. If you can't find any, buy a bag of ice from the store and let it melt. That is pure-enough water! Check the EC of whatever water you wind up using. My "tap" water is 1.2 EC and I grow at from 1.4 to 1.8, so you can see I have to be careful when crafting my nutrients.

Next, a "neutral pH" sounds like trouble. Use this link: http://www.gthydro.com/vegetables.html to view some common pH values for plants. Growing in a "neutral pH" won't work for long! I use a nutrient that is self-buffering, but I'm not so sure of the properties of yours.

Use this link: http://www.gthydro.com/vegetables.html to view some common EC values for plants. You already know where I stand with EC meters, so we won't go there. Suffice to say, you must have the proper EC and pH for stuff to grow properly.

As far as water temperature goes, you're fine. Once a plant is in the "vegetative" stage, a root temp of 84 degrees is "heaven", but the nutrient must be both oxygenated and circulated or other problems will develop.

Have you ever tried static hydroponics using perlite? It doesn't get any easier than that!

you'll need magnification to see spider mites. often times where they've eaten on leaves, the dead area will have a web appearance. your leaves look thick though so it might not be apparent.
The bug on the underside of your leaf wasn't a whitefly was it? slightly larger than a gnat and very white.
And as freemans pointed out, nuetral is not where you want your pH. most, though not all, plants like a pH of around 6.0