Washing machine and appliance overflows
Two rubber hoses sit behind the washer holding back full house pressure around the clock, running or not, for as long as anyone leaves them there. No other single component in a laundry room fails as often.
- 1 The ceiling stain. It measures the ceiling, not the leak. Water travels along a joist before it drops.
- 2 A burst supply line. Pressurized, so it runs until somebody closes a valve, and it runs downward.
- 3 A frozen line. The exterior wall is where the pipe meets the cold, and where it splits.
- 4 The washer hose. Rubber under constant pressure, and a standpipe that overflows quietly.
- 5 The water heater. It goes at the bottom of the tank, usually while the house is empty.
- 6 Groundwater and backup. Water pressing on the wall, and a floor drain that reverses when the combined sewer fills.
Hoses fail while nobody is home
When one lets go it does not trickle; it discharges at line pressure until a human closes a valve. The prevention is dull and costs very little: braided stainless instead of rubber, changed on a schedule rather than on failure, and both valves closed whenever the house is empty for more than a weekend.
The standpipe backup
The pump empties the drum faster than a restricted standpipe can swallow, so the difference comes back up and over the rim: almost always onto a basement floor, almost always mid-cycle with nobody in the room. Lint and detergent build-up do most of it; in older Maryland housing a partly obstructed lateral out to the street does the rest.
The slow ones are the expensive ones
None of the slow ones announce themselves. A dishwasher wetting the cabinet base it sits on, an ice-maker line weeping behind a refrigerator nobody moves, a laundry connection dripping quietly into the cavity behind it. These get discovered by nose, by a floor that has gone spongy underfoot, or by a stain arriving on the ceiling of the room below.
Upstairs laundry changes the arithmetic
Laundry moved off the basement floor and onto the bedroom level in a great deal of the newer housing across the Maryland suburbs, and it changes what a failure costs. On a basement slab, a hose letting go makes a puddle and a wet-vac afternoon. On the second story, the same volume goes through the floor, into the ceiling cavity below it, along the joists, and down inside the walls of the rooms underneath, which is three rebuilt surfaces instead of one and a considerably longer drying job.
The drain pan under the machine is the standard answer and it is only half of one, because a pan is useful exactly as far as its drain line goes. On a good installation that line runs to a standpipe or outside; on a great many it runs nowhere at all, and the pan simply fills and spills at the same rate. It is worth looking under your own machine to see which kind you have, because it takes a minute and it decides whether the pan is a safeguard or a decoration.