Use caution when dealing with hot water!

Hot water can be dangerous.  Adults and children alike can be scalded or become sick with Legionnaires’ disease if your hot water system is not setup properly.

Furthermore, installing hot water systems is dangerous.  Improperly installed systems can cause carbon monoxide to enter the home or cause home explosions.

We advise you to have a licensed professional install, tune and maintain all your hot water systems.  Doing things wrong could be a life or death situation.  

DO NOT TAKE THESE RECOMMENDATIONS LIGHTLY.  IGNORING THESE COULD LEAD TO DEATH.

Hot water safety checklist

• Have a licensed professional install your hot water systems
• Have an annual inspection and maintenance of your hot water systems by a licensed professional
• Keep children away from hot water heating systems
• Install anti-scald devices on every hot water fixture
• Set your storage tank water heater no lower than 140° F to prevent Legionnaires’ disease
• Install a mixing valve to reduce the output temperature of your hot water heater to 120°.  This protects your family against scalding
• Install carbon monoxide detectors, preferably hardwired or wirelessly linked detectors on all levels of your home or office and in all bedrooms
• Consider a tankless hot water heater to enable precise control over output temperature
• Consider a sealed combustion hot water heater (tankless or power vent hot water heater) to ensure exhaust gasses are vented outside
• Test the air around your hot water heater to ensure it is not emitting excess levels of NOx (Nitrogen Oxide) or CO (Carbon Monoxide) into your home

Scalding Information

How Fast you can get scalded by hot water

Hot water 154 degrees fahrenheit or warmer will scald you instantaneously.  It takes 2 seconds for a first-degree burn with 140 degree fahrenheit water, and 3 minutes for a first-degree burn with 120 degree fahrenheit water.  It is critical for you to keep your hot water tap temperature no warmer than 120 degrees.

Temperature

Time for First Degree Burn

Time for  Second Degree Burn (Permanent)

110° F

Normal Hot Shower – No Burn

Normal Hot Shower – No Burn

120° F

3 Minutes

9 Minutes

126° F

30 Seconds

90 Seconds

131° F

5 Seconds

25 Seconds

140° F

2 Seconds

5 Seconds

154° F

Instantaneous

1 Second

Source: ASSE-Plumbing.org

Original reporting: https://hotwaterlab.com/hot-water-safety/