What To Do If There's Air in My Hot Water Lines?


By far, hot water lines cause some of the most irritating plumbing issues. One of the most annoying issues is air in your hot water lines. Below, I will cover the leading methods for getting air out of your hot water lines. However, first, let us discuss how air gets trapped inside your water system in the first place.

Air in the Water Lines: What Causes It?

Unfortunately, it isn’t always simple to figure out what is causing the problem. But it is possible to classify the culprits into two classifications — those only affecting the hot water or those affecting both the cold and hot supply simultaneously.

Trapped Air in Well-Fed Systems

Once the water supply is well-fed, it may cause the air to appear inside the water lines. This situation might occur for a few reasons.

First off, it might be a sign of a faulty check valve, allowing contaminants to seep into the water supply and may possibly be harmful.

Secondly, it might indicate that there is methane entering the water supply through your pipes. Even though gas is flammable, it is technically not a danger to the water supply — however, you should have it repaired, nevertheless.

Finally, sometimes the feed line cannot protrude inside the well water as far as it should. So, it might begin to let air enter the line and lead to more problems.

Trapped Air in Gravity-Fed Systems

If the water supply is gravity-fed, air might become trapped in your supply once it is cut off for maintenance purposes. If that happens, luckily, it’s one of the simplest problems you might encounter. It is possible to resolve it by just running the taps for a little while and allowing the air to flow out.

Air That Is Trapped Inside Hot Water Systems

If you do not frequently purge the heater, sediment may accumulate and cause air to become trapped. Sediment accumulation typically happens in well-fed systems, yet thankfully, there is a simple method of fixing it. In cleaning the system, you’ll permit all trapped air to escape and then be able to fix the system in only a matter of a couple of hours.

Now that you’re informed about how air winds up in the water system, let us discuss how you might resolve the issue.

5 Methods of Getting Air Out of Your Hot Water System

First Method

Start by shutting off the power and leaving on the cold water to allow the tank to cool for around 30 minutes. If the water system is gas operated, you will have to turn the switch off near the bottom of the tank. But if you own an electric tank, you will need to turn off your circuit breaker.

Place a plastic tarp underneath the drain tap and then connect a hose line that carries all the runoff to the sewer. To empty the tank, open up the drain valve. It will force out all sediment or trapped air. Once the water begins to run clean again, it means you have drained the tank, and it is possible to shut the drain valve to enable the tank to fill up again. Finally, when the tank is full, you can restore the power and appreciate your air-free, fresh supply of water.

Second Method

It is even possible to use your washer to eliminate excessive air in your hot water system. Disconnect your red (hot) water pipe, and then connect the blue (cold) pipe in the red (hot) one’s place. Open up the cold water and hot water tap and allow them to run for 3 to 5 seconds. If the problem persists, repeat that process.

Third Method

Be certain that you have first switched the main water line off so you do not make a mess when you are attempting to resolve the problem. If you have several floors in your home, start with the top one, or at the fixture that is adjacent to the space in which the water supply enters your house.

Open all faucets and allow the water to run to permit the air to escape. When the air begins to flow normally, turn off all the fixtures and switch back on the water line.

Fourth Method

Be certain the water valve is attached to the boiler to make sure there is water available. Open up all the valves that run to different heating zones in the house and switch off all the shutoff valves.

Find one of the spigots that come off of the return line and connect a garden hose to it. Open up the spigot and self-feeding valve in order to drain the water into a bucket or drain. But be careful because the water will be extremely hot. Finally, allow the water to run out of the garden hose until you cannot see air bubbles.

Fifth Method

Sometimes, unfortunately, you cannot get all of the air out of the hot water system, and you will have to replace the pipes. If you have attempted all the aforementioned methods, and nothing works, it might be an indication that the valves are blocked. Mainly, that happens because your home’s appliances or pipes are not properly set up. If that happens, you will likely have to employ the services of a mechanic and get them inspected and have them resolve the problem.

Now that you know the cause of excess air in the hot water lines and how you should go about fixing it, let us discuss the easiest methods of spotting it.

4 Indications of Air in the Hot Water Lines

As stated earlier, it is typically very noticeable when there is air running in the hot water lines. The simplest method of figuring out if there is excessive air is if you reside in a house with steam registers. If that’s the case, the pipes will begin to make a pinging sound that you won’t be able to ignore.

One other telltale sign is the water not being able to flow anywhere but out of the faucet. Also, if the pipes begin vibrating at lower pressures — the flow of water is likely completely off. Finally, if the water looks milky or cloudy, it might be a sign that there is trapped air in the hot water lines.

Plumbing systems may make some extremely unusual sounds; in fact, they can even be used as cheap scares in horror movies. The prolonged vibrating noises and loud gurgling are nothing to be concerned about! It’s just a sign that there’s air caught in the water pipes.

Below is a discussion on some solutions associated with water line issues.

Ways to Get Air Out of the Heating Pipes

It is recommended to use an automatic bleeder to get the air out of the heating pipes. If your heating pipe has too much air, an automatic bleeder is going to be your best bet.

Even though it is going to take more time than you initially expected, you will eventually achieve the result you’re looking for. A manual bleeder has a complex process of installation. The process will be much easier if you use an automatic bleeder.

3 Steps to Removing Air from the Pipes

Switch Off the Main Water Supply Valve

Locate the main water supply valve and be certain that it’s fully switched off. Depending on if you reside in a cool or warm climate, it should be inside or outside.

Open All Faucets

To assist in getting all of the air out of the pipes, you should switch on all faucets in your residence or commercial building (after you have switched the water valve off). Do not turn on your faucets at full force, only enough to allow the air to escape. Essentially, you want all faucets with a water connection (which includes your dishwasher and washing machine) to be turned on. Begin with the faucet nearest the shutoff valve and then work your way to the faucet that is farthest away. Open all cold and hot faucets about halfway to allow the air to run out. Keep in mind to also flush all of the water out of the toilets.

Switch the Main Water Supply On

When all the faucets are switched on, which includes the spigots outside, switch the water valve all of the way on. Allow the water to run through all the faucets for 10 to 15 minutes to ensure that you’re seeing a continuous water stream, or are not hearing any sounds coming from the pipes anymore. For dishwashers and washing machines, pour in one cup of water and allow the appliances to go through a rinse cycle. A continuous flow is a sign that there’s no more air in the water pipes. Then you can switch off all the faucets by working your way back from the one that was the farthest to the faucet that was the nearest.

Having air in the pipes won’t damage your residence or commercial building’s plumbing system; therefore, there is no need to worry! What folks usually confuse air in the pipes with is the probability of a water hammer situation. Water hammers occur once water running through the piping rapidly changes direction because somebody switched on a faucet or water valve too quickly— which forces the water to run back into the pipes. It may damage the water system and cause excessive pressure.

If you have low water pressure or are still having plumbing problems, it is better to get in touch with a plumber to ensure that the issue is not more severe. Professionals have the appropriate training and tools to assist in identifying existing plumbing problems and provide solutions to have them fixed.

How Air Gets into the Water Pipes

There might be different methods through which air might enter water piping. The pump’s valves may be the reason for air entering the water pipes.

Usually, pumps contain two valves – one the foot valve and the other the check valve. It might be possible that one of those valves has become loose and is causing the air to get into the pipes. Check if they’re tight enough. You should replace the whole valve if the issue is too severe.

One other reason may be your water heater. Water heaters should be occasionally purged. If you fail to purge a water heater, this may be the reason for air entering the water pipes.

There’s one other reason for air entering the water pipe. The water supply’s feed line must be positioned deep into the well. If it isn’t positioned deep enough, air may enter.

Will Air in the Water Pipes Produce Damage?

Many people have the misconception that air inside the water pipes causes damage. However, air won’t cause damage to the water pipes.

Air creates some sounds that can be very annoying. In addition, the water flow may be inconsistent. Other than that, air won’t cause damage to your water pipes.

Also, many people take air and water hammer in the water pipes as the same thing – which it isn’t. Water hammers occur once you open up a faucet and shut it off too quickly.

That’s how water changes its direction too quickly, creating a backward pressure inside the waterline. However, air won’t cause damage to the pipes.

Air won’t harm your water lines, but you should get the air out of the water lines as soon as you can.

Make sure you follow this guide, and if the problem is too severe, call a plumber.

In Summary

One of the common problems that professional plumbers encounter is air in the hot water lines. But as discussed in this post, there are several tricks to try without hiring a professional to fix this problem. I hope this article helps you to easily and quickly get the air out of your hot water system. Feel free to contact me if you have any questions or have any issues outside the scope of this post.