water heater troubleshooting
Water heater is leaking
What it probably is, what you can safely check yourself, and the point where it becomes our job.
Do not wait this one out. Shut the system down and phone us — running it in this state usually turns a repair into a replacement.
What is most likely going on
Shut off the cold water supply to the tank and turn off its power or gas, then find where the water is coming from. Fittings, the drain valve and the temperature and pressure relief valve are repairable; a tank leaking from the shell is not, and it needs replacement.
Likely causes, most common first
- 1
Corroded tank shell
When the glass lining fails, the steel corrodes through and water seeps from the shell or from beneath the jacket. There is no repair for this: the tank is finished and continuing to run it risks a full failure and a flooded floor. Water appearing from under the jacket with dry fittings above is the telling sign.
- 2
Leaking temperature and pressure relief valve
The T&P valve discharges when the tank exceeds its temperature or pressure limits. A dripping T&P can mean the valve is failing, or that the tank is genuinely overpressured from a thermostat fault or a closed system without expansion control. Never plug or cap a T&P discharge line; it is a safety device doing its job.
- 3
Loose or corroded supply connections
The cold inlet, hot outlet and any flex connectors are the most common leak points and are usually repairable. Dielectric unions corrode where dissimilar metals meet, and a slow weep at a fitting will stain and mineralise before it drips visibly. This is the good outcome when you go looking.
- 4
Drain valve dripping
Plastic drain valves weep after being opened for flushing and sometimes will not fully reseat. It looks alarming because water is at the floor, but it is the least serious cause on this list and often a simple replacement.
- 5
Condensate from a heat pump water heater mistaken for a leak
A heat pump water heater dehumidifies the air around it and produces condensate, so a blocked or disconnected condensate drain puts water on the floor without any tank fault at all. Before condemning a fairly new unit, check the condensate line, especially in a garage installation.
What you can safely check yourself
Work down the list before you book anything. Plenty of calls end here, and we would rather you keep the money.
- Shut off the cold water supply valve at the top of the tank.
- Turn off the breaker for an electric or heat pump water heater, or set a gas unit to its pilot or off position.
- Dry everything, then look with a flashlight to find whether water is coming from a fitting, the T&P valve, the drain valve, or from under the jacket.
- On a heat pump water heater, check whether the condensate drain line is blocked or disconnected.
- Move anything valuable off the floor nearby and note the tank’s model and serial label for us.
What is deliberately not on that list
Nothing above involves refrigerant, gas piping, or opening a live electrical panel. Refrigerant work is federally regulated and needs recovery equipment. Gas work done wrong kills people. An energised panel turns a $300 repair into a hospital visit. Electrical work on the circuit itself is done by a licensed electrical contractor. If a step you have read elsewhere involves any of those three, stop and call instead.
When to call us
Call us now if water is coming from under the jacket, if the T&P valve is discharging, or if you cannot stop the flow with the supply valve. A leaking tank in a finished basement or an upstairs closet does damage quickly, and the shut-off is the important first step. Emergency calls are answered 24/7 at (360) 592-3824.
Monday–Friday, 8:00 AM – 5:30 PM · Emergency calls answered 24/7
Tell us what it is doing
Describe the symptom and we will tell you what it takes to fix, what it is likely to cost, and whether it is worth fixing at all.
Monday–Friday, 8:00 AM – 5:30 PM · Emergency calls answered 24/7