If your washing machine is overflowing the drain, chances are, it’s draining too fast. Luckily, there are a few easy fixes to get rid of the problem.
Fixing a washing machine that drains too fast is usually a simple matter of restricting water flow, replacing the plumbing, or removing build-up in your drain lines. Of course, fixing the issue means diagnosing what’s affecting the waterflow first.
How Does a Washing Machine Drain Water?
Washing machines pump water in and out of the drum using a pump. In most cases, these pumps are custom, 2-way pumps, designed to first draw water into the washing machine and then pump it out. Here, the pump pulls clean water into the drum where it is circulated to clean or rinse laundry. Then, the pump pushes dirty water out through the filter and through the drainage hose. Once it crosses the U-bend against the wall, the gravity does the rest, pulling the water down the drain. From there, water flows out, past the P-Trap, and into your sewage system – either a local or a city septic tank.
When water enters the drainage pipe faster than it leaves, you start to have problems. Water might backup and flood into the room. And that can be a severe problem depending on how badly it is overflowing. But even if water is only slightly backing up, you likely want to resolve the issue and fix your drainage problem.
5 Common Reasons Why Your Washing Machine Drains Too Fast
If your washing machine is draining too fast, it’s probably easy to figure out why. However, your problem might be hidden so far down in the pipes you need a professional inspection to find it.
Old pipes can cause backflow and overflow issues with any modern washing machine. This relates to a lot of problems including corrosion, pipe size, and trap size. So, if your pipes are more than 20 years old, you might have issues just because of the old pipes. For example, if some of your plumbing wasn’t installed according to modern code, it might be too small to handle water flow capacity. To check, make sure all plumbing between the washing machine and the sewer is 2” or larger.
Damaged pipes have a tendency to leak, to backflow, and to overflow. Damage might be caused by cold, damp, tree roots, pressure, or accidents. However, it can result in cracked, broken, collapsed, and filled pipes. These will (naturally) not allow water to pass through at the same rate. Unfortunately, it can also be difficult to diagnose without a plumbing inspection. However, you can inspect your plumbing for leaks, for visible cracks, and for patches that indicate a leak in the yard – such as damp spots or bright green patches of grass.
Clogs and Buildup
Drain lines can easily clog. However, clogs don’t have to stop waterflow entirely to be problematic. Partial clogs, known as buildup, can actually cause drains to overflow, because water doesn’t flow through quickly enough to avoid the problem. An overflow issue that gets worse over time is a good indicator of a buildup problem.
Buildup can be caused by fat, lint, large objects such as tissues or gloves, tree roots, hair, and other small material that can collect in one place. Tricks to get it out vary, and you might need professional assistance.
Newly Installed Washing Machines
If you have a newly installed washing machine or you’ve had the problem since the machine was installed, you might have two other very common reasons for the machine to drain too fast. These include that the drain might not be high enough off the wall and that the pipes might be the wrong size.
Washing Machine Drain Height – Washing machine drains are designed to be installed at height. For most, this means at least 2’ off the floor and no more than 8’ off the floor. If your drain is too low, you’ll experience backflow. Or, literally, water drains back into the washing machine and possibly onto the floor. For this reason, nearly all standard washing machine drains are installed 30’ off the floor. That also holds true if the P-trap is too low. Your P-trap should ideally be 6-18 inches above the floor and the standpipe 18-30 inches above that. If you lower this too much, you’ll have problems.
Pipe Size – All modern washing machines require a 2” drainage pipe. However, if you previously had a very old washing machine in place, it might not have had that. Older standards used a 1.5” drainpipe. Unfortunately, these smaller drainage pipes are not enough to handle the drainage capacity of modern washing machines. Instead, you’ll have to replace the plumbing to resolve the issue. Fortunately, that’s probably an easy fix, as most wall pipes are 2”. This means you’ll have to replace the P-Trap, the standpipe, and the plumbing to the wall with larger, 2” PVC pipes. And, best of all, you can do that for as little as $15 – $40 in supplies.
How to Slow Down Washing Machine Drain
While it’s often a good idea to speed up water flow through the drain rather than reducing your drain, you can choose to reduce it instead. In fact, doing so requires a few simple tools and a screwdriver.
How to Unclog a Washing Machine Drainpipe
Checking for clogs is the best way to get your waterflow moving again. It’s also highly likely that a clog or partial blockage is the culprit.
Pour hot water down the drain
Boiling water is a tried-and-true way to remove top-of-drain clogs, especially if they’re from buildup like laundry detergent or fat. The hot water melts the lipids in the buildup, causing everything to wash away. Most plumbers will add plenty of dish soap to this mix, which prevents the clogs from re-hardening and causing a clog further down the pipes as soon as they cool.
Consider a chemical declogger
Chemical decloggers are a great way to remove blockage in your pipes. You can choose to use homemade versions like baking soda and vinegar. However, an over-the-counter clog remover is specially formulated for removing clogs from drains. It will also be formulated to be safe to use in your drain. If you buy one of these, be sure to follow the instructions on the bottle, as chemical makeup and usage can vary significantly between brands.
Use a drain snake
A drain snake is an inexpensive coil of twisted wire with an attachment on the end to remove clogs. Snakes are available from about $7-$35 from most stores, in lengths ranging from 10-75+ feet. Most home users are only comfortable using medium-length snakes – so consider using a 10-40-foot option. Here, you want to insert the snake into the drain and twist it down until the snake stops going. Then, work the snake in rotations until it comes loose and continues moving. Keep going until you’re left with just the handle above the standpipe.
Consider having your drains flushed and cleaned
Sometimes you’ll have drainage issues that are well below your ability to fix them. In this case, you’ll want to ask a plumber to inspect your pipes and, if recommended, to flush and clean them. While most households can go quite some time without cleaning the drains, some areas make that impossible. That’s especially true if you have very low water pressure, so drains will frequently contain sediment and buildup.
DIY Washing Machine Flow Restrictor
Before you begin, it’s almost never a good idea to do this. Installing a flow restrictor will create backwards pressure on the pump, which could cause your washing machine to fail early. However, if you have no other alternatives, installing a drain restrictor might be a good idea.
Things You Will Need
Before you go shopping, measure your washing machine drainage hose. You want to check the diameter of the flexible hose coming out of the back of your washing machine. Make sure you measure at the plastic hose, not at the gooseneck which tapers or expands the end. In most cases, the hose should be 1” or 1.5” however some washing machines have drainage hoses up to 2”.
- A reducer fitting going from the size of your washing machine hose to about a half inch down
- A radiator clamp capable of fitting over the drainage hose
- A screwdriver or hex screwdriver. Most radiator clamps feature a flat screwdriver head but check what you’ve purchased to make sure you have the right tools.
In some cases, the gooseneck or fitting on the end of the drainage hose will be glued on. In this case, you might have to use a hacksaw to take it off.
Remove the Gooseneck
Remove the gooseneck from the end of the hose. In most cases, it should slot off. In other cases, it might have a small press-release. And, in some instances it will be glued on. Make sure it’s off and set it aside in case you intend to use it again.
Insert the Reducer Fitting
Place the radiator clamp, with the metal in a ring, over the hose, and slide it out of the way. Then, insert the fitting into the hose. And push it firmly into the back of the hose. You may choose to use pipe cement to permanently attach it. However, this might not be a good idea if you end up having problems with the pump.
Tighten the Clamp
Adjust the radiator clamp over the top of the reducer fitting and use a screwdriver to tighten it as much as you can. The clamp should be tight enough that you cannot remove the reducer fitting.
Replace the Hose
Insert the drainage hose back into the standpipe.
How to Seal a Washing Machine Drain Hose
Before you proceed with these steps, it’s important to note that you should never seal a washing machine drain hose. Doing so will create a vacuum lock in the plumbing, which will vacuum siphon water out of the washing machine. Essentially, sealing the washing machine drain hose will render your washing machine unusable. In addition, it may actually cause the pump to burn out.
Make Sure You Have a P-Trap Installed
If you don’t have a P-trap installed, your washing machine will likely smell. It also increases the chances of water overflowing because you’re more likely to have upwards pressure from the drain. So, the best way to “seal” the drain from the sewer is to install a P-Trap. This should be 6-30 inches off the floor and no more than 2 feet away from the drain in the wall.
Clean or Replace the Pipes
You can also choose to simply replace all of the pipes. This immediately removes any issues you might have with buildup in the pipes causing unwanted smells or overflowing. And, it ensures that any new pipes are installed to modern code, to prevent overflow.
3 Ways to Prevent a Washing Machine Drain from Overflowing
There are quite a few reasons your washing machine drain might be overflowing. Preventing those is normally about preventive maintenance, checking your pipes, and ensuring everything is properly installed.
Check the Plumbing Installation
If your plumbing is too small or improperly installed, it will overflow. The easiest way to check this is to do a simple assessment with a tape measure. Consider the following checklist:
- How wide is the standpipe and drainage pipe?
- Is there a P-Trap?
- How tall is the standpipe?
- How far from the floor is the P-Trap?
- How far from the drain is the P-Trap?
- Are there blockages or existing reducers on the pipe?
The drainage pipe should be 2” and a minimum of 24” off the floor and a minimum of 6” off the P-Trap. The P-Trap should be a minimum of 6” off the floor and no more than 24” from the drain. And, if you have blockers or reducers in the plumbing, they might have been installed to mitigate an older system. Try removing them and see if it helps.
Perform Regular Plumbing Maintenance
Regular plumbing maintenance can keep your drains clean and running smoothly, even if you have low water pressure. Consider performing routine maintenance by flushing drains with boiling water. Use dish soap or drain unclogger depending on if there’s an actual clog or not.
If you have real drainage problems, it’s always a good idea to ask a plumber for an inspection. Often, initial inspections are even free. This will give you a good idea of what state your plumbing is in and what steps you have to take to resolve the issue.
Clean Filters and Traps
Washing machine filters, drain traps, and additional traps at the top of the drain can prevent clogs by catching dirt and lint. However, they can also cause overflow when they become clogged. For example, if you use a vent filter in the standpipe, you’ll likely have to clean it every 30-60 days. In addition, your P-trap might occasionally clog with hair, lint, sediment, or even small articles of clothing. If your washing machine drain is overflowing, don’t be afraid to take it apart and see if there’s something in the P-trap.
If your washing machine is flooding, fixing it is a priority. However, we always recommend looking for a permanent fix, like replacing the plumbing or resolving clogs, rather than using reducers. And you should never seal your drain pipe because it can literally burn out your washing machine pump.
Good luck finding and fixing your problem.