You pop into the laundry room to check if the load needs changing out and the washing machine is frozen in place with “SUD” flashing across the display. Here’s what it means and what to do.
The “SUD” error code is found in a variety of high-efficiency washing machines including Whirlpool, Kenmore, and Samsung models. The error indicates that there is an excess of soaps suds in the washer drum and it’s inhibiting functionality—this is known as a “suds lock.”
In the vast majority of cases, the issue is a result of using too much detergent in your high-efficiency washing machine. Thankfully, if you’ve used too much detergent, the machine has a routine for dealing with the suds lock, and you can usually just leave it alone. Your washing machine might appear frozen or broken when you see the “SUD” error. However, your washer is just pausing to allow the soap bubbles to break down (like the bubble foam in a bubble bath goes flat over time). Then it will run a rinse cycle to break up and rinse away the remaining detergent. You might even have gotten the SUD error before, but weren’t in the laundry room to see it. Leave it be for a bit and check on it to see if it has completed the cycle. If it has not, unplug your washer for ten minutes, plug it back in, and manually run a rinse cycle.
While the SUD error is almost always caused by too much detergent, it can also be caused by a partially obstructed drain (which reduces the effectiveness of the rinsing and keeps more suds in the drum). Checking the drain trap on your washer isn’t a highly technical job, but it does typically require some hand tools and a plastic pan or bucket to catch the excess water. If you’re comfortable getting your hands a little dirty (and a lot wet), search Google for your washing machine model and terms like “drain cleanout” or “clogged drain.” You’ll likely find a YouTube video or service manual to reference.
Barring excessive detergent or something obstructing the drain, the error can be triggered by failing components such as the pressure sensor that detects the suds or the pump itself. If reducing the amount of detergent and checking the drain filter for obstructions and gunk doesn’t resolve the issue you may need to contact an appliance repair shop.