Why Your Tankless Water Heater's Leaking in Detroit Winters

Tankless water heaters are known for their efficiency and convenience, but like any system, they’re not immune to problems — especially during harsh Detroit winters. If you’ve noticed your water heater leaking when temperatures drop, it’s a sign that something isn’t working as it should. Understanding the common causes can help you take action before a small leak turns into serious damage.

1. Frozen or Cracked Pipes

One of the most common reasons for leaks in winter is frozen water lines. When water inside the pipes freezes, it expands, putting pressure on both the pipes and the internal components of your tankless unit. Once temperatures rise and the ice begins to thaw, those cracks can start to leak. If your system isn’t properly insulated, it’s more vulnerable to this kind of damage.

2. Internal Condensation Build-Up

During winter, temperature differences between the cold air outside and the hot water inside the system can create excess condensation. While some condensation is normal, excessive moisture inside the unit can lead to water dripping from the bottom or sides. Over time, this can affect the electronics or cause rust inside the unit if not addressed.

3. Worn or Damaged Seals

Tankless water heaters rely on rubber seals and gaskets to keep water contained within the system. Cold weather can cause these components to contract or wear out faster, leading to leaks around the fittings or connections. These seals may harden or become brittle in low temperatures, especially if the unit is installed in an unheated space like a garage or basement.

4. Improper Installation or Sloped Venting

Another reason for winter leaks is improper vent installation. If the venting system is not sloped correctly, condensation from exhaust gases can flow back into the unit instead of draining outside. This water can then leak out of the heater casing. This issue is more noticeable during winter due to the higher contrast between indoor and outdoor temperatures.

Preventing Future Leaks

To prevent costly damage, timely tankless water heater repair is important, especially in Detroit, where freezing temperatures can put extra strain on your system. Make sure the unit is properly maintained, pipes are well-insulated, and the heater is installed in a temperature-controlled space whenever possible.

Addressing small leaks early can help you avoid major repairs and keep your water heater running efficiently all winter long.