Kitchen Sink Not Getting Hot Water: A Troubleshooting Guide

When a kitchen sink is not getting hot water, it usually indicates a blockage of transfer between the water heater and the faucet. But before we dive into troubleshooting this, let’s clear up one important question:

Is the faucet not getting water at all through the hot water side or is water coming out but not hot? Depending on which situation you have the solution will differ.

But first, the basics. What causes your kitchen sink to stop getting hot water?

There could be a few reasons why your kitchen sink is not getting hot water. It could be caused by a failure in the faucet cartridge, an issue with the water heater, or a blockage in the faucet. Examine each possible issue until you find the one that is causing the problem with your kitchen sink.

When it comes to plumbing, it is not always easy to find and locate the source of your issue without some troubleshooting. Read on to learn what specific problems could be preventing your sink from receiving hot water and what steps you can take to determine the exact issue. 

Kitchen Sink Faucet Not Getting Hot Water, Only Cold

If there is no water coming out of the hot water side of your kitchen faucet, there is a blockage between the water heater and the sink. This could be as simple as a closed valve or a debris buildup in the piping that is preventing water from flowing.

Be sure to check the easy potential causes first. Look underneath the sink where the water valves are located and ensure that the hot water valve is completely turned on. 

If the hot water valve is completely turned on and you aren’t getting hot water, check other areas of the home to see if those faucets are getting hot water. If they are, the blockage is likely in the faucet itself or the piping to it.

However, if other areas are not getting hot water either, then the problem is most likely tied to your water heater. If you suspect the water heater is the main cause of the kitchen faucet not getting hot water, you need to inspect it for signs of failure.

Water Heater

One of the most obvious and common causes for lack of hot water comes from the water heater itself, provided the home has one. Water heaters can degrade over time. You may not notice until it has gotten to the point that your water heater is beyond repair. Some common problems with water heaters are:

• Rust and corrosion develop, causing a leak 
• Heating elements fail

Rust and Corrosion

Before your search gets too complicated, inspect the water heater itself. Make sure that there are no leaks that have developed and there is no rust or corrosion that you can easily see.

If there is a water leak that has developed due to rust or corrosion, it will most likely be obvious. If a water leak has developed, the odds are that the unit will not be able to be repairable, and you will have to purchase a new one.

However, if the leak is caused by any other issue other than rust or corrosion, it may be salvageable. You must first determine where the leak is occurring from and trace it to its cause.

Some common causes for leaks other than rust and corrosion in the water heater are:

• An over-pressurized temperature and pressure valve
• A leaking gasket or inlet valve
• A loose pipe connection

If any of these things is the case in your situation, fix the issue, and that should hopefully cause your water heater to work properly once more.

Heating Elements Failing

The lack of hot water in your kitchen sink could simply be because the water heating elements inside of the water heater are failing. To check this, shut off the water and electrical supply to the water heater and follow the instructions for your unit to remove the heating elements.

Once you have removed the heating elements, check them for any signs of rust, corrosion, or other damage that would cause them not to work properly. If there appears to be damage to the heating elements, order new ones for your specific water heater.

Related Reading: Water Heater Not Filling Up? Here’s 4 Likely Reasons & Fixes

Most heating elements can be purchased online and start at roughly $9. When the new heating elements arrive, install them in the same manner in which you removed the old ones, and you should have hot water restored to your kitchen sink.

Shop for water heater elements online (link to Amazon). Make sure to choose one compatible with your model.

Cartridge Issues

If you have a single action kitchen faucet, it will have a cartridge that is installed inside, which controls the amount of hot and cold water that flows based upon how you turn the faucet. The cartridge itself is typically installed inside the faucet.

Over time, the cartridge inside of the faucet collects debris that will eventually cause a blockage. When the blockage gets large enough to obstruct water, it will prevent hot water from coming out of the faucet.

To check the issue and repair it, you must remove the cartridge from the faucet to inspect and clean it. The specific process will depend on which type of faucet you have, but you can follow these steps, in general:

• Shut off the supply of water to the faucet
• Remove faucet handle with a screwdriver or Allen wrench
• Remove the cartridge from the faucet with needle-nose pliers or standard pliers
• Soak the cartridge in white vinegar overnight to remove any mineral build-up

Before you can test or repair your kitchen faucet, you must first shut off the water supply. The water controls should be located under your sink for easy access. You can shut them off by turning them in the opposite direction they are currently in.

Once you have shut off the water, check your faucet to determine how it is secured, with either a screw or Allen head. Carefully remove whatever is securing it and take care not to lose the screw—they are typically small and easy to misplace.

Once you locate the cartridge, remove it with a pair of needle-nose or standard pliers. Inspect the cartridge to see if there are any obvious areas of mineral build-up that you can remove. If, after cleaning what you can see, you want to make sure all of the mineral build-ups are removed, soak the cartridge in white vinegar overnight.

Once you have thoroughly cleaned the cartridge, rinse it in water to remove any loose particles that you cannot see. Reassemble your faucet and turn the water back on under the sink. If the issue was debris in the cartridge, this should solve your kitchen sink’s hot water problem.

Line Blockage

Like mineral build-up in the cartridge, there could also be a blockage in the water lines preventing hot water from making it to your kitchen sink. To check to see if there is a blockage in the waterline:

• Turn off the cold-water supply under the sink
• Loosen the cartridge and turn on the hot water

When you turn on the hot water in your kitchen sink during this process and water does not come out, there could be a blockage in the main body of the kitchen faucet. To remove the blockage, turn off the hot water supply underneath the sink.

Remove the hot water supply line from the faucet and place a bucket underneath the hot water connection. Turn on the cold-water supply and use your finger to block the spigot of the faucet. Once the spigot has been blocked, turn on the cold water which should cause the water to travel through the hot water inlet.

The water traveling through the hot water inlet will force whatever is causing the blockage out of the faucet. Once the blockage is removed, reassemble your kitchen sink, and the hot water should be flowing freely once more.

Final Thoughts

Numerous things could cause your kitchen sink to stop running hot water. Take the time to inspect the possible causes until you discover what exactly is the root of the problem. Following the steps in this article should allow you to diagnose and correct the hot water issue with your kitchen faucet yourself, without hiring an expensive professional.

Related Reading: Why Is My Bathtub So Cold? 4 Key Causes & Solutions