Water as we know it should be both odorless and colorless. Why then would the hot water from your faucet be white or cloudy?
Cloudy/white hot water is caused by dissolved air bubbles due to increased water pressure. When you turn on the faucet, the dissolved air bubbles are released and hence the cloudy appearance. The cloudy water clears in a few minutes from bottom-up as the water pressure reduces.
Cleaning or replacing the faucet aerator will in most cases fix the cloudy appearance of your hot water. If the problem is affecting all your faucets, consider flushing your water heater or contacting your local municipal water department.
So, why is the cold water clear while the hot water is cloudy?
One thing to remember is that the solubility of air in water increases with an increase in the water pressure. The solubility will also increase with a decrease in temperature.
Cold water holds more dissolved air than hot water. When water is heated, its ability to dissolve air reduces, but since the water is held in the pipes or water heater, the air bubbles are trapped there as well.
When you fill a glass with hot water, you will notice that the cloudy appearance clears after a few minutes from the bottom-up. The reason for this is that the hot water which was trapped under pressure in the pipes or water heater has its pressure hence the reason the air is clearing from the water
This is the same thing which happens when you first open a bottle of soda. The only thing with soda is that it is usually cold. If sodas were sold hot, you would observe the same thing if you poured it in a clear glass.
Cloudy/white water is harmless and totally safe to use. The cloudy appearance is as a result of an increase of pressure which increases its air solubility. When you turn on the faucet, the air is released and hence the color. It however clears in a minute or two.
The kind or air we are talking about in this case should not be confused with trapped air in water pipes. This is dissolved air in water and not an airlock in your plumbing.
Troubleshooting Cloudy/Milky Hot Water Problem
Although the white cloudy appearance in hot water is primarily caused by dissolved air bubbles, it could also be caused by sediment in the water heater, and especially lime/calcium. So, how can you know what is causing it in the first place? Very easy!
Fill a clear glass or bowl with the hot cloudy water and watch how it behaves. This is what will tell you the source of the problem.
If the cloudy appearance clears in a minute or 2 flow the bottom-up, you have dissolved air bubbles in the water. On the other hand, if the cloudy appearance takes longer to clear and when it does it clears from top-down, you surely have sediments in your water heater.
Another thing you need to investigate is whether the problem is affecting only one faucet, or all the hot water faucets in the house.
If the problem is only restricted to one faucet, you most likely have a clogged faucet aerator. When the problem is affecting all the faucets, the problem could be coming from your water heater or the water municipal department.
A faucet aerator is the small attachment at the tip of the faucet spout. It is usually mesh-like with fine holes, and its main function is to prevent the faucet from splashing water.
Due to how small its holes are, they are easily clogged by mineral deposits and pipe corrosions. When that happens, water has to force its way through the faucet, which increases its pressure.
Think about it. When you want to increase the pressure of a hose, you block most of its opening with your thumb. It is the same thing here.
As we have said, increase in water pressure, means an increase in air solubility. The hot water therefore dissolves more air which is released once the water lands in the glass and its pressure has been reduced.
How to Fix the Cloudy Hot Water Problem
Removing the white cloudy color in your hot water can actually be very easy and fast. We will start with the faucet aerator as it is what causes the problem for most people.
1. Clean the Faucet Aerator
The faucet aerator is usually threaded to the faucet spout and can be hand tight or tightened with a wrench. Here is how to remove and clean it:
- Start by boiling ½ cup of vinegar and placing it in a bowl near the faucet.
- Check if the faucet aerator is hand tight or crazy tight. If it just hand tight, turn counterclockwise to loosen it.
- If it is very tight, use a wrench or a pair of pliers to loosen it. To avoid peeling off the finish from the faucet, wrap a towel or duct tape on the aerator before grabbing it with the wrench.
- Remove the aerator’s washer, ring and screen. Drop them in the vinegar and wait for 15 minutes.
- Use and old toothbrush to clean the components and especially the screen until they are spotless.
- Arrange them as they were before and connect them back on the faucet.
If the old aerator looks badly worn out, a replacement might be the best option. Check your faucet brand and model number and order a similar replacement.
Turn on the hot water and check if the cloudy hot water appearance has disappeared.
2. Flush the Water heater
Flushing a water heater is the process of draining it and in the process removing sediment settling at the bottom of the tank.
As we know, sediments like calcium which is white in color will dissolve in water to form a white/milky solution. By flushing the water heater, you will be able to remove this sediment.
- Start by turning off gas to your pilot if you are using a gas water heater or turning off power to an electric water heater at the breaker. Draining the tank with the elements on will burn them.
- Turn off the cold water shut off valve.
- Connect a garden hose to the drain valve at the bottom of the tank and direct its other end in a surface drain or out into the driveway.
- Turn on the drain valve with a flathead screwdriver and let the tank drain. As soon as you turn on the drain valve, open the nearest hot water faucet as well. Leave it open. Let the tank drain out completely.
- When the tank is fully drained, turn on the cold water valve for a minute, then off, then on for a minute a couple of times. What this does is to agitate the sediment at the bottom of the tank, so that you can flush out as much of it as possible.
- Turn off the drain valve and disconnect the hose.
- Open the cold water valve and allow the tank to start filling.
- Keep an eye on the hot water faucet you left open. As the tank fills with water, air will be flushed out through the it. This helps to prevent buildup of trapped air.
- As the water starts flowing out of the faucet, it will be sputtering as the air is being flushed out. Only turn the faucet off once you see a continuous and soft stream of water.
- Turn on the pilot light or power to the water heater.
And basically that is how to flush sediments out of a water heater. Give the hot water sufficient time to heat and then turn on the hot water faucets to check if the problem is fixed.
If unfortunately you are unable to fix the problem, call your water supplier to check if they are performing any sort of maintenance on the water lines. You can as well contact a licensed plumber for more troubleshooting.