Symptoms
- Water dripping from pipe connections at the top of the tank
- Leak near where pipes enter the tank
- Top of tank feels damp or has mineral crust
- Fittings may look corroded or loose
Likely causes
- CommonLoose inlet or outlet pipe fittingThreaded connections can loosen slightly over years of thermal expansion and contraction.
- CommonFailed or corroded nipple fittingThe dielectric nipples where pipes meet the tank can corrode and leak.
- PossibleLoose or failing T&P (temperature and pressure relief) valve connectionThe valve or its discharge pipe fitting can loosen or corrode.
- PossibleCondensation mistaken for a leakOn humid days, condensation can form on the cold inlet pipe and drip, mimicking a leak.
What to do
- Turn off power or gas and the cold water supply to the tank before inspecting closely.
- Dry all top fittings completely with a towel.
- Run water briefly (with power/gas still off) and watch each fitting closely for the exact leak point.
- If it's condensation, the pipe will sweat evenly rather than drip from one specific threaded joint.
- Tighten a loose fitting carefully with a wrench, avoiding overtightening which can crack fittings.
- If a nipple or fitting is visibly corroded, plan to have it replaced rather than just tightened.
Tools and parts
- Adjustable wrench
- Towels
- Flashlight
Dielectric nipple fittingSearch: “water heater dielectric nipple”
When to call a pro
If tightening doesn't stop the leak or a fitting is corroded, a plumber can replace the fitting without needing to replace the whole tank.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.