One of my dishwashers called for 140 degree incoming water to work properly. My kids are older and we all know how to work the faucets so we don’t get burned. We also know not to touch the stove, oven, grill, smoker, motorcycle and car exhausts, etc. so as not to get burned. None has been burned more than I’ve and never by the water. The pipes can handle it.

I think setting it to 120 to save energy was a government thing, then it became a safety thing, for the children. We also don’t set the HVAC to 68 in the winter or 78 in the summer as we prefer to be comfortable.

quote:

Originally posted by Blume9mm:
One of the interesting things I've noticed about the gas tankless heaters is they are all 200,000 btus or greater.... that's burning a lot of gas.

Only for the relatively short time they are actually heating water. Since I built my home in 1997 I have been keeping track of all my utilities. When I replaced my propane tank water heater with a tankless my propane usage dropped by over 30%. That was with 2 kids playing sports in the family.

quote:

Originally posted by smlsig:

quote:

Originally posted by Blume9mm:
One of the interesting things I've noticed about the gas tankless heaters is they are all 200,000 btus or greater.... that's burning a lot of gas.

Only for the relatively short time they are actually heating water. Since I built my home in 1997 I have been keeping track of all my utilities. When I replaced my propane tank water heater with a tankless my propane usage dropped by over 30%. That was with 2 kids playing sports in the family.

My results are similar. In the Summer our gas bill is sometimes as low as $26.

Like many of those before me, we went tankless ( Rinnai ) . It was one of the better decisions we made on home upgrades. Descale the unit every so often and you are good to go.

We bypassed the factory max home owner setting and cranked it up to 130. I know, not the best thing we ever did, but I take a long and hot shower plus the heat loss in the lines makes it perfect for us.

quote:

Originally posted by Blume9mm:
One of the interesting things I've noticed about the gas tankless heaters is they are all 200,000 btus or greater.... that's burning a lot of gas.

That's max output, Turn-down ratio is ~10:1 for combi boilers, meaning they can output 20k-200k. I don't remember how dedicated tankless heater turn down. It's heating ~50* water to 120* very quickly. It will fire at max for a short time on startup to get the heat exchanger hot, then roll off.
Combi boiler in my shop is 60k heat, 120k max DHW. If the heating is active & I start using DHW it barely increases heating for the DHW (it will switch over to DHW & stop heating). If it's cold, it goes full blast for about 10sec, then rolls off & will cycle off for a short time with just the sink tap open.
It might use as much gas in 5 minutes as a tank heater will use in an hour, but the tankless is only running for minutes vs the tank running 24/7.

Don’t know if you have the option, but my water heater is oil fired. Very fast cycle (minutes) and we never run out of water. Also economical, it is the only oil we use since we went with geothermal hvac.