If you’ve ever made a pot of spaghetti you most likely have poured boiling water down your drain. And if you’ve read anything at all about best tips on maintaining your water pipes, you may now be wondering if it’s even okay to pour boiling water down your sink.

Well, the answer is not so clear cut because it depends on the material your pipes are made of and the material your sink is made of.

Know that boiling water is 212° F so any pipe (or sink for that matter) that cannot tolerate that temperature will not be able to stand up to being subjected to the high temperatures of boiling liquid.

So, let’s go through a list of materials your water pipes could be constructed out of.

What Are Water Pipes Made Of?

Below is a list of the different materials water pipes are made of and what temperatures they can withstand.

  • Iron – 2570° F
  • Copper – 1981° F
  • Galvanized Steel – 392° F
  • Pex – 200° F
  • CPVC – 200° F
  • PVC plastic – 140° F

The answer to “Can you pour boiling water down your sink drain?” is: If your water pipes are made of Pex, CPVC or PVC – they are NOT made to withstand the temperature of hot, boiling water.

If your water pipes are made out of Iron, Copper or Galvanized Steel – you certainly can run very hot water through them but if there are any rubber or plastic joints – those can get damaged over time as they are not made to withstand such high temeratures.

Of course, a one time incident will not necessarily harm these pipes but if every Tuesday night is Spaghetti night you may want to consider running cold water down the sink while you drain your pot of steaming, hot water.

Will Boiling Water Damage PVC Pipes?

The general rule of thumb is that hot boiling water can soften or even slightly melt the joints in your PVC pipes so YES, if you subject these types of pipes to high temperature water on a regular basis – they can be damaged, causing leaks and eventually requiring replacement.

For stubborn clogs – we recommend our Hydro Jet Cleaning service. The process is extremely efficient, cost effective and environmentally safe. It’s simply a superior method of cleaning out your pipes, downspouts and sewer lines. Give us a call at 770-505-8570.

Does Boiling Water Unclog Drains?

Honestly, you would have to use gallons of boiling water to unclog a drain. It may end up damaging your pipes before you can loosen up that clog.

Some people will recommend mixing boiling water with baking soda but again, you would have to use gallons of hot water and the baking soda is abrasive for cast iron pipes and pvc and cpvc pipes so – it’s not something that we recommend.

Another note to mention is that if your sink is porcelain – you may want to reconsider the boiling water idea. Hot water can cause minor cracks in anything made out of some form of china (sinks, toilets, tubs, etc.).

So, for proper maintenance of the pipes in your home, be aware of what they are made of but to stay safe – avoid pouring hot, boiling water down your drains as much as possible.


If you have questions about maintaining your water pipes or are having problems with clogged drains, call the Atlanta experts – Atlantis Plumbing today at 770-505-8570. We are available 24 hours a day, 7 days a week.