should ac drain line be capped

Should AC Drain Line be Capped? Find Out the Answer!

Many believe that it’s good to cap the AC drain or condensate line. While others state the complete opposite that capping does not provide any benefits. So, it’s pretty obvious to feel lost about what to do with your AC drain line!

Now, the question you want answers to is – should ac drain line be capped?

Most AC drain lines do not require it to be capped. However, you can cap it if you want to. It solely depends on the usage and condition of your AC. There are some instances where capping the line ended up clogging. While others did not encounter any significant disadvantages.

You might think that you’ve learned enough to make a decision but wait! Because there are still some discussions left. 

So, let’s get on with that!

Should AC Drain Line Be Capped?

AC is a common gadget. It is used now worldwide. So the problem related to AC is important to be solved. There are often problems related to the drainage of water. A question: should the ac drain line be capped is related to the drainage system.

should the ac drain line be capped
Source: Reddit

The ac gives a cooling temperature inside your room. But carry a hot temperature and drain water from the internal atmosphere. Now, this whole process is heavily influenced by the power output. So, the power outage can generate AC noises if you’re not careful!

The condenser coil of an AC remains on the outside. It drains the water into the main pan. When there is troubleshooting in the main pan, the emergency drain pan gets the water. Now come to the question: should the condensate line be capped?

Your AC drain line should not be capped. But it will not create so many problems if you cap it. If you fix the coil on the right side then you don’t need to cap. But if the coil is on the negative side then you have to cap the trap.

A very common issue with drain lines is that they get clogged up very often!

Some companies claimed that the line should not be capped. But it’s actually up to your ac. If your ac provides more with the cap then go for it. But if you find problems after capping, then you should remove it.

Benefits of AC Drain Cap

As it’s up to your ac service, there are some advantages also present. Some people find more comfort after using a cap. There may arise some other problems. Like your ac is properly working for a certain time. But the ac is not working the rest of the time. 

These problems are interlinked. We have discussed the advantages below.

Increased Efficiency:

A cap can increase the efficiency of the ac. The cap holds more air. It prevents air from coming out from the interior. As the air can not come out, the room becomes colder. If it is not capped, the air will blow out.

AC Drain Cap
Source: Air Pros USA

That will cause your ac to work more. So if there is no other problem, you can cap it. It will give you the best service.

For Draining Purposes:

Along with the efficiency increase, there’s another great advantage of condensate lines. It can provide an excellent draining mechanism for your AC. So, should the ac drain line have a trap? 

For a proper drain system, a trap is much needed. It helps to continuously drain the water. If the primary line is blocked, water drains through the secondary line. 

There are many types of traps present. But finding the right one can be a chore! To ease your pain, here are some top recommendations from users like you-

Mostly there is a cap in the primary drain line. For this, the air pushes the water out. Also if you cap, the condensate water will not go to the emergency pan.

The cap is used mainly to keep the temperature constant. No air can escape due to the cap. It is a plus point if you want to use a cap.

The Disadvantage of AC Drain Cap

Now that you know about the advantages, it’s time for the negatives to give the stage. Hopefully, it does not come as a shock that drain cap has its cons too. So, let’s check out what those are.

System Overflow:

Some companies say that, if you cap the drain it will overflow. The water will not drain properly due to the cap. While it is capped, the air is unable to push the water. Then the water can not drain through the primary drain line. It will flow out from the emergency pan.

Also if it is capped, the weather can not blow out. Rather the water goes to the system. It causes overflow internally. So any occurrence may take place. Your ac will not respond well. It will rather cool your room, and start to work more to blow out the water.

Clogged Drain Line:

The cap can affect the drain line also. The line starts clotting for the cap. To know if there is any clot present or not, you can find out by measurement. 

So, how much should ac drain line drip? 

5 to 20 gallons of condensate per day is the optimal line drip. If the amount is less, then there is clotting in the line.

Clogged Drain Line
Source: R&B Climate Control

Also, you can find it simply. If there is a clot, the water will drain into the emergency pan. You can follow some steps to get rid of troubles like this. Also, you have to clean your AC’s condensate drain line regularly.

What Are the Factors to be Considered After Capping?

If you decide to cap the ac drain then you have to follow some tips. These will help to work your ac in the best way. Sometimes people face clotting problems. What can I pour down my ac drain line? It is a quarry that capped its ac drain line.

  • You should regularly check the drain line.
  • The ac drain line should not be capped with glue.
  • You should gently press the cap to further clean the pipe.
  • You can use 1/4 cup of vinegar if you find any clot. Pour it into the line.

You can follow these tips to avoid any drainage-related problems. These tips will cut off half of the capping problems. So if your ac drain line is capped, keep in mind these points.

Frequently Asked Questions (FAQs)

Is bleach or vinegar better for AC drain lines?

Vinegar is better for AC drain lines. Vinegar has no corrosion effect. It only gives a strong smell after washing. But bleach can damage your drain line if there is a presence of copper. Bleach can also damage the surrounding clothing materials. So we recommend vinegar.

How often should you pour bleach into the AC drain?

Use bleach a maximum of two cups up to two times a year. But it is not recommended to use bleach as it has a corrosion effect. It can damage the line. Rather you can use boiling water to clean the lines. You can use a thin stick or rod to remove the clog. Then wash it with water.

What causes the AC drip pan to overflow?

The clogged line can cause the pan to overflow. The water comes to the draining line from the condensate line. It will pass through the line and go outside. If there is any obstruction or clogged in the line, it can not blow out. So the water goes back and overflows into the drip pan.


You’re now all equipped to make your decision. We hope you got the proper idea about should ac drain line be capped or not!

Keep in mind that your AC will only be as good as its owner. So, try to take care of it and follow the official instructions.

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