Drano is a popular American brand of drain cleaner. It is commonly used in kitchen sinks to clean out dirty drains and to help unblock them if you’re having drainage issues.

For dishwasher users, the issue of a blocked drain can be a major problem. What’s the point in having a dishwasher if it can’t drain away all the water after the wash? When you encounter this issue, you may consider using Drano to try and resolve it.

Today, we’ll be looking at whether this is a good idea or not while also looking at other methods that you should consider for unclogging a dishwasher.

Can you put Drano in a dishwasher? The simple answer

Drano shouldn’t be used in a dishwasher. While it is a useful product when it comes to unblocking drains in sinks, it isn’t suitable when it comes to unblocking a dishwasher.

Not only is it unlikely to actually resolve the problem, but it also contains toxic chemicals that can cause permanent damage to your dishwasher. One of the main ingredients in Drano is sodium hydroxide and while this chemical isn’t acidic it can cause lasting damage to plastic.

Why is Drano not suitable for dishwashers?

Drano isn’t designed to unclog plastic pipes due to the sodium hydroxide we mentioned above. When sodium hydroxide is mixed with water, a significant amount of heat is generated. While you may think this is a good thing because it’ll clean out your pipes, it is also going to melt your plastic dishwasher pipes and cause permanent damage to them.

Not only will your dishwasher’s drain pipes become damaged if you apply Drano but the chemicals within Drano could end up splashing onto your plates and bowls when you next turn your dishwasher on. The last thing you want to do is ingest sodium hydroxide as you are going to suffer from poisoning if you do.

Those who have eaten or drank sodium hydroxide have suffered from severe internal burns amongst other symptoms. This damage could be permanent so it’s something you are going to want to avoid at all costs.

To summarise, pouring Drano into your dishwasher is going to melt your dishwasher’s drainage pipes and leave behind toxic chemicals. In other words, it’s an absolute non-starter.

What should you use Drano for?

While we’ve established that Drano isn’t a good idea for unclogging a dishwasher, it is still a useful product to have at your disposal. It’s primarily used for unclogging kitchen and bathroom sinks.

The ingredients within Drano are superb for breaking down hair and soap scum, meaning your drains will be unblocked in no time by using this product. However, you should refrain from using it for unblocking a toilet. This is because the heat that radiates from Drano could damage a toilet’s PVC piping.

Additionally, the cause of blockages in toilets is usually unrelated to hair or soap scum. Instead, it’s usually a build-up of toilet paper or foreign objects getting stuck in the pipes. Drano would simply burn through these items.

How to unblock a dishwasher

If you can’t use Drano to unblock your dishwasher then you may be wondering what options are available to you.

Signs that you have a blocked dishwasher

The key to unblocking a dishwasher is to, first of all, establish that you do have a blockage in the first place. Here are a few concrete signs that your dishwasher is blocked:

  • Your dishwasher makes a gurgling noise while it is running a cycle.
  • Water from the dishwasher backs up through the pipes and comes through the plug in your sink.
  • Everything in the dishwasher is still dirty after a cycle.
  • Water sits in the bottom of the dishwasher after a cycle.

Reasons for a blocked dishwasher

Once you’ve confirmed that you have a blockage, you will then need to establish the cause of the block. Here are a few possible explanations:

  • Failing to pre-rinse your plates and bowls before placing them in the dishwasher. This will result in large chunks of food getting stuck in your dishwasher’s drainage system causing a clog.
  • Failing to clean the drain filter inside the dishwasher. This is what protects the drain hose.
  • Putting too much dishwasher liquid into the dispenser. While it’s important to add a cleaning agent to the dishwasher, too much can cause a blockage.
  • An issue with the plumbing in your home in general.

A guide to unblocking a dishwasher

Once you’ve established the root cause of your blocked dishwasher, it’s time to get to work on fixing the issue. Here is a basic step-by-step guide that should unblock your dishwasher:

  1. Remove all items from the dishwasher, including the cutlery rack and the filter.
  2. Put on some rubber gloves and work at removing any debris from the filter and piping. You may come across old food and/or bacteria so this won’t be the most pleasant of tasks but it’s an essential one all the same. Soak the filter with hot soapy water and leave it to soak.
  3. Use an old cup to fish out any excess water that is lingering at the bottom of the dishwasher and then check the sprayers for any debris as well.
  4. Mix together some warm water and white distilled vinegar and place it in a cup on the top shelf of your dishwasher. Run a cycle on your dishwasher this cup in place. Vinegar is an excellent agent for removing any dirt that is causing a blockage because of the acetic acid found within it.
  5. After the cycle is complete, load your dishwasher as normal and test it out to see if the blockage has been removed. If you are still seeing signs of a blockage then it may be time to call in a professional plumber to resolve the problem.


To conclude, Drano should not be used to try and unblock a dishwasher. In fact, it is one of the worst things that you could put in your dishwasher because it’ll either result in permanent damage to your dishwasher or permanent damage to your body. To effectively unblock a dishwasher, please follow our guide above.