Search online for recommendations for your water heater, and you’ll find a number of suggestions. The truth is, there is no single best residential water heater temperature setting, because variables always apply. Here’s what to understand about possible variables, and how they affect the right water heater temperature in your home.
If your water heater has a tank, you pay to keep that water hot – whether you’re using it or not. That’s incentive enough for many people to ask us about tank-less hot water heaters, but another workaround is lowering the temperature on your water heater. The standard temperature is 140F, but energy experts recommend dropping it by about 20 degrees to reduce consumption and save money.
Lowering the temperature on your water heater is more efficient, but it’s also safer – especially if you have small children or senior citizens in your home. A water heater set to the standard 140F means extremely hot water coming through your tap. And yes, it will cool slightly as it travels through the pipes, but it’s still hot enough to mean scalding burns. Turning down the temperature on the water heater by just a few degrees is an easy way to reduce this risk without shivering through lukewarm showers. Don’t turn it down by too much, though – burns are an important safety consideration, but so is sanitation.
While 120F should be hot enough to prohibit most bacterial growth, those with compromised immune systems should keep water temperatures above at least 122F. Some bacterial strains, including those causing Legionnaire’s Disease, can thrive in anything cooler than that. Some dishwasher models that don’t heat water themselves also need higher temperatures – water should be heated to between 130F and 140F to clean and sanitize dishes properly.