When your sink has hot water, a basic household function that depends on your water heating system and plumbing layout. Also known as hot water supply at the faucet, it’s often the first thing you notice when something’s wrong with your home’s water system. But if only the kitchen sink has hot water—and not the bathroom, shower, or laundry tub—you’re not just dealing with a minor annoyance. You’re seeing a symptom of a deeper issue in your water heater, the appliance responsible for heating and storing hot water for your entire home or your plumbing system, the network of pipes, valves, and fittings that deliver water to every fixture.
Most people assume if one sink works, the whole system is fine. That’s not true. A sink with hot water while others don’t usually points to a blockage, a faulty mixing valve, or a problem with how the hot water lines branch off from the main heater. It could be a clogged aerator, a stuck valve in the faucet, or even a broken dip tube inside the water heater. If your water heater is older than 8 years, it’s also possible the internal components are failing unevenly. You might think it’s just a faucet issue, but it’s often the heater struggling to push hot water far enough through the pipes. In homes with older copper or galvanized pipes, mineral buildup can choke off flow to distant fixtures while leaving the closest one—like the kitchen sink—untouched.
Don’t ignore it. A sink with hot water while the rest of the house doesn’t can lead to bigger problems: frozen pipes in winter, increased energy bills from the heater working overtime, or even a full system failure. If you’ve tried flushing the water heater, checking the thermostat, and cleaning the faucet screens—and it’s still only the sink that works—it’s time to look at the bigger picture. The fix might be simple, like replacing a single valve. Or it might mean your water heater is at the end of its life. Either way, knowing the difference saves you money. The posts below cover real cases from Northampton homes: how a broken dip tube killed hot water to the bathroom, why a faulty thermostat made only the kitchen work, and how to tell if your water heater is worth repairing—or if it’s time to replace it. You’ll also find step-by-step checks you can do before calling a technician, so you’re not overpaying for a simple fix.
If your shower has no hot water but the sink does, your water heater is fine-something’s blocking the hot water just to the shower. Common fixes include cleaning the showerhead, replacing the mixing valve, or flushing the pipe.
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