Water Heater Leaking? What It Does to the Walls Around It

A water heater leaking inside a closet rarely looks like an emergency. There is no burst pipe and no water pouring across the floor. What there is, most of the time, is a wall that stays wet on the side you cannot see, and a room next to it that starts to smell wrong a few weeks later.

This post covers where tank water heaters leak, what to shut off first, and what the water does to the walls and floor around the heater once it gets into them.

What we found on a recent job in Simi Valley

This month our crew has been working a job in Simi Valley that started at a water heater closet. The gas water heater sat in a closet that opens to the outside of the house, with a bedroom on the other side of the wall.

• On the first visit, our team took moisture readings on the closet walls around and behind the tank, then along the walls of the bedroom next door.
• A follow-up visit added a thermal camera and more meter readings along the baseboards, and the areas of drywall and baseboard to be removed were marked out on the photos.
• Plastic containment went up in the bedroom before any drywall came off.
• The water heater was pulled out of the closet, and the closet drywall was cut back to the framing.
• In the bedroom, the drywall was cut along the bottom of the walls and the carpet was pulled back.

Most of the evidence on this job was inside the walls, not on the floor. That is the pattern with a water heater closet, and it is why a leak that looks small can end with drywall coming out of two rooms.

Where a leaking water heater usually leaks from

Before you call anyone, it helps to know where the water is coming from. On a standard tank heater, look at these spots:

• The connections on top. The cold inlet, the hot outlet and the flex lines that connect to them. A slow drip here runs down the side of the tank and can look like the tank itself is leaking.
• The temperature and pressure relief valve. The valve on the side or top with a pipe running down toward the floor. Water from this pipe means the valve opened or is failing, and a plumber should look at it.
• The drain valve near the bottom. It can drip if it was not closed all the way after the tank was flushed.
• The tank itself. Water coming from the bottom of the tank, with rust on the base, usually means the tank is done. A leaking tank is not repaired. It is replaced.

Age matters here. According to InterNACHI, the typical water heater lasts about 10 years, so a leak on an older tank is often the start of the end for that heater.

What to do in the first hour

1. Shut off the cold water supply at the valve on the line going into the top of the heater.
2. Turn off the energy source. Set the gas control to off or pilot on a gas unit, or switch off the breaker on an electric one.
3. Take photos before you clean anything up. The closet, the floor, the base of the walls and anything stored nearby.
4. Call a plumber for the heater and a restoration company for the walls and floor. They are two separate problems.

What the water does to the rooms around it

Water heaters usually live in closets, garages and utility rooms, which means they sit against drywall and next to other rooms. Here is where the water goes once it gets out:

• Up the drywall. Drywall wicks water upward from the bottom edge, so a wall can be wet well above the floor line.
• Through the wall. A closet wall is also the wall of the room behind it. On the Simi Valley job, readings were taken on both sides.
• Under the flooring. Carpet pad and the tack strip along the wall hold water long after the carpet surface feels dry.
• Into the framing. The bottom plate the wall sits on and the base of each stud stay wet the longest.

Time is the problem. The EPA says that if wet materials are dried within 24 to 48 hours of a leak, in most cases mold will not grow. A closet leak that goes unnoticed for weeks is well past that window, which is why jobs like this one often turn into mold after water damage jobs.

What the restoration side looks like

1. Find the wet area. Moisture meters and a thermal camera show how far the water traveled, including into the next room.
2. Contain it if mold is likely. Plastic walls and air filtration keep dust and spores in the work area.
3. Remove what cannot be dried. Wet drywall, baseboard and carpet pad usually come out.
4. Dry the structure. Air movers and dehumidifiers dry the framing and subfloor. This is structural drying, and it is checked with readings, not by touch.
5. Rebuild. New drywall, texture, paint and flooring once everything reads dry. Our construction team handles that part too.

If you want to know what a job like this runs, our breakdown of water damage restoration costs in Ventura County walks through what drives the price.

FAQ

Is a leaking water heater an emergency?

A steady leak or water from the relief valve is. Shut off the water and the energy source and call a plumber. A slow drip is less urgent for the heater, but the water it leaves behind still needs to be dealt with before it gets into the walls.

Can I keep using a water heater that is dripping?

Not until a plumber has found where the drip is coming from. A loose fitting is a small fix. A leaking tank means replacement.

How do I know if the wall behind the water heater is wet?

You usually cannot tell by looking. Swollen baseboards, bubbling paint or a musty smell in the next room are clues, but a moisture meter is the only way to know for sure. A slab leak hides the same way.

Found water around your water heater?

Total Restoration handles water damage restoration across Ventura County, Santa Barbara County and Santa Clarita. We find where the water went, dry it properly, and rebuild what had to come out. Contact us and we will get someone out to take readings.