Strange but real question please. Will the dish washer still disinfect your dishes if the water doesn't get hot from the sink very well?

In California I use to wash the dishes using extremely hot water. My hands were use to the heat. In Arizona it's a different kind of water system and to me the water doesn't get hot sometimes. So now that i am paranoid of germs, will the dish washer still kill the germs if the sink water doesn't feel hot to me?

You would be better off with really hot water to help disinfect dishes. They recommend running hot water through the faucet first to get the cold water out of the pipes.

I'm not sure about solar or tankless water heaters, but on most tank water heaters the temperature can be set.  The tank heaters are usually set at 140 F from the factory.  The Department of Energy recommends 120 F.

If you have a tank water heater, sediment could be keeping your heating elements from doing their job. I drain and flush my water heater about every 6 months. But I have a well. It wouldn't need it that much for city water.  Elements can also go bad and the water would not get as hot as it should.

The easiest way to check and change your temperature would be to see which kind of water heater you have and do a YouTube search. They have videos for just about everything.

I think most dishwashers have their own heating element. If you don't have the manual to your dishwasher, you can look it up online. The make and model number should be along the door. I have a sanitize setting on my dishwasher and I know my water heater does not get hot enough for that.

Mine does if I use the "Sanitizing" heat setting on the dishwasher.  (I'm pretty sure they all have a similar feature.)

These sites have great information that should answer most (if not all) of your questions about dishwashers and sanitation.

https://www.myrecipes.com/convenience/can-dishwasher-really-kill-bacteria

(There is a video that plays within the site--"linger" long enough to read the banners that it shows, then go on (or just come back to it later.)

https://homeguides.sfgate.com/dishwashers-sterilize-84323.html

https://stopfoodborneillness.org/news-from-stop-clean-sanitize-disinfect/