Good temp for DHW from a propane on-demand unit?

[drewmo]

Our new house has a Pensotti propane boiler with on-demand hot water. What's a good temp to set the DHW at so that's it's not too hot when showering (defeats the purpose of efficiency to cool the water down), but yet still hot enough to get the dishes clean in the dishwasher? If you have a similar set up, what temp do you have it set at?

 

[sloeffle]

Our DHW is set at 125. I see it as a happy medium. IMHO 130 is about too hot, and 120 seems a little too cold. You want to keep your temp at 120 or greater to prevent Legionnaires’

(broken link removed to https://www.cdc.gov/legionella/wmp/overview/growth-and-spread.html)

 

[billb3]

I have a mixing valve at the water heater. I can add cold water to the hot water so that a child or anyone else for that matter can't get scalded. OSHA recommends 140º tank temp for Legionnaires and that can be a good temp for other bacterias like iron bacteria as well.
The scalding temp at the faucet is really going to depend on the dia meter and length of pipe between the heater and faucet.
It is usually recommended to set temps at the closest faucet.

Your dishwasher doesn't have a water heater ? They usually take "hot" water and heat it to about 160ºF
They often recommend running the water at a nearby faucet until it runs hot so a dishwasher actually gets "hot" water to start with. Some don't do a very good job heating cold water hence the need to run the faucet to bleed out the room temp water. Partly because there really isn't much water in a dishwasher and there can be quite a bit of water in a pipe.

 

[fbelec]

i second what bill said. if you read the dishwasher directions they usually require 140. my dishwasher is automatic to where it runs until it's reaches a curtain temp for the cycle that it's in. and if the water is cold going in it runs longer especially if it is on and usually is on sanitize rinse. if it has cold water feeding it cuz the hot water didn't get that far it will run for a extended time and it might not get to the 160 mark and won't sanitize. how i know is the light doesn't come on and say sanitized when it is done