Cold Water Not Working? Here’s Why

If you’ve found that your cold water isn’t working, leaving you with only boiling hot water, it can be frustrating. Luckily, the fact that it’s just cold water that’s not coming actually narrows down the problem areas for you. While it’s still a pain, at least your work is slightly cut down when it comes to troubleshooting, right?

The most common causes for cold water not working are a faulty shutoff valve, frozen or blocked pipes, or a faulty pressure-balancing valve.

Keep reading to help pinpoint the exact problem and learn how to take precautions to prevent it from happening again!

Cold Water Not Working: What to Check First

As said above, there are three primary causes that just your cold water isn’t working. If you’re having issues with both hot and cold water, however, things change a bit. Let’s assume that you have hot water aplenty, and get down to it, shall we?

Shutoff Valves

This is the valve located underneath your sink (or near to whatever your source of water is). Its function is to, well, shut off hot and/or cold water to your sink. If you live alone, this is a less likely thing to have gone wrong, but it’s worth a check nonetheless. And if you have kids or roommates, it’s definitely a good place to start.

Locate the valve and turn the cold water knob (usually denoted with blue colouring) to see if your cold water starts up. As a note, if you have no cold water in the entire house, it’s almost guaranteed that this isn’t your problem. Though you can certainly still check this on all of your water sources, just to be sure.

Pressure-Balancing Valve

If you have no cold water in just your shower, this is a great place to check out. Unfortunately, this is going to be a fix for a professional plumber, as it’s quite involved. To get an idea of what it looks like, click here to see a video showing a valve replacement.

Frozen or Blocked Pipes

If you live in an area that gets below freezing in the autumn or winter, this is a good place to look – especially if it’s just recently started to freeze. Take a look at your home’s plumbing plans (if you have access to them) and try to check that your cold water pipes aren’t frozen anywhere.

To prevent frozen pipes, leave a small drip running in your sinks when you know a freeze is coming. This will prevent water from standing still and freezing in the pipes.

To fix frozen pipes, you’ll need to apply heat to the section that has frozen. This can be done with a hairdryer or heating pad – but not with any form of flame or space heaters. This can lead to housefires and actually damage your pipes.

Another possible alternative is that you could have mineral buildup or refuse if it’s a pipe from the kitchen that is preventing cold water from getting in. If only your cold water is affected, this is less likely, but still possible. You can try flushing the pipes with vinegar and baking soda, though it’s likely that this won’t solve the problem.

Other Reasons Your Cold Water is Not Working

There are a few other minor reasons that your cold water could have stopped working. Take a look below to see if these may be the source of your problem.


If you’ve noticed a drop in water pressure prior to losing cold water altogether, you may have a leak somewhere in your home’s piping. Look for water damage or water buildup and, if you find it, call a plumber for help.

Water Purifiers

If you have a water purifier built into your sink, this could be a potential source of the problem. Try doing a manual reset on the water purifier to see if it fixes the issue. Sometimes, water pressure will get too high (or the purifier’s sensor thinks it has) and it will prevent water from coming through as a safety measure.

Supply Line Damage

Take a look under your sink. The supply line will be the thinnest pipe you see. If the supply lineis bent or damaged, that could be the source of the issue. You can try manually straightening it with a wrench or other tool, though it may be best to simply replace it.

Faulty Washers

If you have an old home, the washers in your tap could have loosened and dislodged. Turn off the water at the source, disassemble the faucet, and replace the washer with a new one. This should result in a smooth flow of cool water.

This is especially important in old homes, as new ones have braided steel lines that lessen the likelihood of damaged pipes, unlike old homes which use copper.

Water Main

If both hot and cold water isn’t coming, this is likely the source of the problem. Check out your water main valve (usually in the basement or near your boiler) and ensure it’s open.

If not, open it up and see if that fixes the issue. Otherwise, you’ll want to call a plumber for help diagnosing the problem.

Final Thoughts

Plumbing is an awfully complicated thing. There are a lot of minor parts that can get damaged or simply shut off by others in your home. If your cold water is not working, begin by taking a look at the water main to ensure it’s open.

After that, you’ll need to take a look at various valves and connectors to ensure nothing has broken, leaked, or worn out. Unfortunately, there’s not much you’ll be able to do yourself here beyond finding the source of your issues so a plumber can take a look. And there’s no shame in that – professionals exist for a reason. Calling them will be the fastest and safest way to ensure you get your water running properly again, though it may cost you a pretty penny.

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About the Author Harry Thompson

Involved in home renovations throughout his life, Harry is an expert in everything to do with home and garden DIY. In his spare time, he enjoys cooking and tending to his garden.