If your faucet’s running hot, these tips will chill it out
Suppose there’s a heatwave and you’ve just spent an hour gardening. You’re looking forward to that glass of water to cool down but suddenly realize there’s no cold water coming out of the faucet. There are a few reasons why the cold water tap might not be working but hot is, ranging from simple fixes to more involved issues. Follow these steps to figure out if it’s a minor repair you can correct on your own or if you need to call in the plumber.
Before getting too far into diagnosing the problem with the tap in question, you should rule out a more widespread issue. Is hot water coming out of the tap? Are the other faucets working? What about the shower? If the answer to any of these questions is yes, you can be confident that it’s not a general water failure caused by the water heater or a problem with the water main or your water supply.
Solution: If you’re not getting water anywhere in the house, find the water main valve—typically in the basement, under the sink, or near the water heater—and confirm that it’s open. If that doesn’t solve the issue, or if you’re unsure about handling the valve, it’s time to call a local plumber to troubleshoot it.
A common reason for not getting cold water is that the shutoff valve for the cold side could be partially or fully closed. If this valve isn’t open all the way, it can block off that refreshing cold water you’re waiting for.
If you have kids or pets, it’s possible that they inadvertently closed the valve—or, if you’ve had repair work done recently, it could be that the plumber neglected to open it back up after the job was complete. It could also simply be stuck from lack of use.
Solution: Under your sink, trace the pipes that supply it with water and search for a knob or lever. Turn it counterclockwise as far as it will go to confirm it’s fully open.
While you’re looking under the sink, another potential issue to check is if the supply line (the thinner line of piping connected to the sink) has become bent or kinked. Though most newer homes feature braided steel lines that are difficult to damage, many older builds still include a more flexible copper or all-metal version that bends easily, choking the water supply.
If you’ve recently organized under the sink or noticed something pressing against the water lines, there’s a chance that might’ve caused the kink.
Solution: Try manually straightening it and see if that gets the cold water running again. If its damaged or old, you might need to replace it—but supply lines are inexpensive and fairly easy to swap out.
If your faucet includes a separate spray nozzle, it’s possible that the feature’s stutter valve, which diverts the water to the nozzle when it’s in the open position, has become stuck. Try running the water through the spray valve a couple times, and see what happens.
If you’re getting water there but not out of the faucet, it’s safe to assume the stutter valve is to blame.
Solution: Turn off the flow of water to the sink using the shutoff valve, which is attached to the pipe underneath. Next, turn both the faucet and the spray nozzle on at the same time before opening the valve again—this should disengage the nozzle’s vapor lock and return water flow to the faucet.
If you live in a cold climate, and you have not winterized your pipes, the most likely culprit in your cold water problem is a frozen pipe. You might notice frost on exposed pipes, or no cold water coming out of any faucet in the house.
Solution: If the sink’s pipe is located behind cabinet doors, open them up to let in a little heat from the house. It’s a good idea to get in the habit of leaving the cabinet open to prevent the pipe from freezing again in the future. For a little extra power, you might also use a portable heater if there’s a safe spot to put it nearby or a hairdryer.
If the pipe was frozen solid, the ice may have damaged the pipe or the faucet, so there’s a risk that thawing the pipe could lead to a leak. If this happens, it’s time to call a plumber.
If a pipe is leaking somewhere in your house, it could be cutting off the flow of water to the tap in question. Water pooling under the sink or a sudden drop in water pressure could indicate a leak. Trace the pipes throughout your house and see if you can find evidence of a leak somewhere.
Solution: There are some short-term solutions for leaking pipes that might lessen the damage, but you’re going to need to call in a plumber to get the cold water flowing again.
Some kinds of under-sink water filter systems can trigger an automatic shutoff to your faucet if the pressure becomes too high.
Solution: Manually set the water to bypass the unit, restoring the flow to the tap—just remember that until you correct the issue with the unit, this water will no longer be filtered.
In some cases, a tap can become blocked simply because the washer has loosened and dislodged, physically blocking the water flow. This may be the case if your faucet handle feels stiff, or you’ve recently had plumbing work done.
Solution: Turn off the shutoff valve, disassemble the faucet, and replace the washer with a new one. If you get a smooth flow of water, your problem is solved! If not, it’s best to get a plumber to come take a look.
A worn-out faucet cartridge causes uneven water flow. If you’ve tried adjusting the shower handle and only get hot water, it’s likely a problem with the pressure-balancing valve in the shower faucet cartridge.
Solution: To replace a shower cartridge, turn the shutoff valve, remove the faucet handle, and take out the old cartridge—located behind the escutcheon (the metal piece used to hide the hole in your wall where the pipe comes through) and often held in place by retaining clips.
Many can be removed with a pair of pliers, but if yours requires a cartridge-pulling wrench, it may be easier to call the plumber than to do it yourself.
Though less common, here are some other possible reasons your water isn’t heating up.
Poor pipe placement: If the cold and hot water lines are too close together, the heat from the hot water line will warm up the cold water flowing through the cold water line.
Water heater problems: A malfunctioning water heater could be causing a mixup somewhere in the system, leading to ultra-hot water or the absence of cold water. You’ll have to hire a local plumber for an inspection to suss out this issue.
Water softener problems: If the softener is too small or lacks adequate power to service your household, you could face low pressure and temperature issues. The same goes if the sediment filter or resin filter is clogged. Escaped resin, for instance, can clog plumbing fixtures, including the cold water faucet.
Damaged copper pipes: Copper pipes don’t corrode or rust, but they are extremely malleable and easily damaged, which can lead to the cold water getting stopped somewhere along the journey to the faucet.
Once you’ve tried all the relevant options above, it’s safe to assume that the problem is too complex for a DIY fix. If none of the above problems apply, then the most likely cause of no cold water coming out of your faucet is a build-up of limescale created by mineral deposits from hard water. This especially may be the case if a steady decrease in water pressure preceded the blockage.
The long-term solution will require installing a different kind of pipe or adding a water-softening system, but you’ll want to leave the determination to a trained plumber.
If your water is lukewarm or even hot when coming out of the faucet, the most likely cause is a blockage somewhere in the system. These blockages are created by limescale buildup, leading to a steady decrease in water pressure and, eventually, the disappearance of cold water. Limescale forms over time in homes with hard water. Other reasons cold water isn’t coming out of the faucet include leaks, frozen pipes, and damaged supply lines, among other causes.
It’s not uncommon to experience warm water throughout the hotter months. Cold water lines are rarely insulated, so can be subject to extreme weather events, including heatwaves. This problem increases when the pipes run throughout multiple parts of the home that aren’t air conditioned.
The likely culprit is an air lock somewhere in your pipes. This is especially true if the warm water upstairs is accompanied by a decline in water flow. Other causes of this issue include frozen pipes, leaks, damaged supply lines, and more. There’s a simple DIY fix to try for air locks: Turn the hot water and cold water faucets on for a minute, then turn off the cold water and then the hot water. Repeat this process two or three times.
