LOL, my shoulders won’t get you very high. But there is a lot of good information right in this forum. This will be a very simple project, I promise!
First off, you asked about the expansion board for the NodeMCU ESP8266 board I’m using:
I’ve got nothing against soldering, but using something like this makes the whole project neater and easy to reconfigure if you find a better way to do things, or just want to try out different options. You should be able to find these on line at Ali Express or Amazon or wherever else you prefer.
I bought the little project boxes on Amazon:
The expansion boards fit right in, and the hard plastic isn’t so brittle that you can’t drill it or even carve out openings with an X-Acto knife.
I found tons of information about using the Dallas temperature probes. A few I made note of were:
and
As for practical issues, get the temperature sensors which are bedded in a stainless steel tube with a waterproof cable attached. I got my last batch from Amazon. The one thing you can’t do with these is put them inside a pressurized system like your water heater. You can buy industrial-grade sensors which come in a threaded nipple you can install into your plumbing, but I didn’t need to incur the expense or risk to get that level of accuracy. I put my sensors up against the metal of the boiler, and the “in” and “out” water pipes, with a bit of insulation over them so they read pretty close to the actual water temperature.