The length of the dishwasher’s drain hose can make a huge difference between smooth, maintenance-free operation and backflowing dirty water. If your dishwasher drain hose is too long, install an air gap fitting or make one or two laps to prevent the wastewater from re-entering the machine. You can also shorten the drain hose by applying the right technique or replacing it with a flexible one.
How long should the Drain Hose be on a Dishwasher?
The drain hose length of a dishwasher varies depending on the distance between the dishwasher and drainage system, installation requirements, and specific model. While a too-short drain hose won’t reach the drain and cause water to flow back, too-long hose can become tangled and cause drainage issues.
In general, most dishwashers come with 6 6-foot or 1.8-meter-long drain hose. If the distance between the dishwasher and drain connection is longer than 1.8 meters, you have to use the longer hose.
But make sure the longer drain hose doesn’t bend or kink sharply as it can disturb the water flow and cause drainage issues. The drain hose should also be secured in place using an air gap or high loop so the dirty water can’t flow back into the machine.
If you need to extend the drain hose’s length, use an extension kit that is compatible with your dishwasher, and don’t void the local plumbing codes. Don’t use the regular garden hose as it can block or leak the drainage system.
Read your dishwasher’s user manual to get particular advice on the length of the drain hose.
How to Prevent Backflow while Using Too Long Drain Hose
You can either install an air gap or apply a high loop to prevent the wastewater from flowing back through the dishwasher when using too long a hose. Installing the air gap is a long-lasting solution, however, requires some DIY skill. In contrast, the high loop method is a quick fix but may need frequent checking or maintenance.
If your bosch or Samsung dishwasher drain hose is too long, you can install an air gap to avoid negative consequences. This fitting is attached around 2” above the kitchen sink to prevent dirty water from flowing back into the dishwasher and mixing with clean water. This separate hose deposits polluted water from the drain hose.
Though there are plenty of ways to prevent the backflow of polluted water, the air gap ensures effective protection against dirty water. However, you may need to follow plumbing codes in the local areas. In the US, you may also need to use commercial food and beverage prep sinks to install an air gap.
However states like California, Washington, and Hawaii require residential dishwasher air gaps.
Installing Air Gap to the Dishwasher
- Create a 1-3/8” hole using a hole saw and electric drill under the countertop or clean the existing one. The hole should be close to the sink edge to provide enough room for the air gap to avoid overflow.
- Connect the drain hose to the air gap’s small side and secure it with clamps.
- Then get a 7/8” tubing to connect the air gap’s other end to the garbage disposal.
- Attach the tube to the Y-branch tailpiece and disposal and secure the connection using a hose clamp.
- Remove the vanity covering from the air gap’s heading and put it into the counter hole.
- Secure the air gap firmly against the counter using a nut.
- Lastly, turn on the dishwasher and run a full cycle to check if the air gap is working properly.
Full circle high loop is a good alternative to the airbag method particularly if you prefer a simple fix. As long as the drain hose won’t kink, this method will work fine.
The high loop separates two parts of the drain hose to prevent backflow of wastewater that can be a result of too long a drain hose.
However, you should also apply a long loop instead of multiple small loops to ensure a smooth workflow. so try to run the drain hose in one or two loops and secure it loosely using something solid like nylon cable ties.
Another consideration is that you must install the drain hose at the right height. So, install the drain hose with a high loop so the water can’t flow back into the machine. Typically a high loop should be around 32” above the kitchen’s floor. If your kitchen doesn’t have much space, apply the air gap method.
To do so, attach the drain hose to the sink or countertop’s underside and create a loop that is higher than the dishwasher’s level.
Shortening the Dishwasher Drain Hose
You can shorten the dishwasher drain hose in plenty of ways to prevent backflow or drainage damage. For example, you can cut in the middle of the drain hose as required and use the heater hose to reconnect the two sides.
Follow these steps to shorten your dishwasher’s drain hose to a perfect length:
- Unplug the dishwasher’s power supply cord to avoid an electric accident while working on the machine.
- Locate the hose that is usually placed at the dishwasher’s back and near the bottom.
- Measure your desired drain hose’s length from the machine to the connecting point of the garbage disposal or drain pipe.
- Cut the hose to the measured length using scissors, a sharp knife, or a branch cutter. Though you can cut the old-style drain hose, you can’t cut the corrugated-style hose.
- You may also need to attach an adapter or a fitting to the end of the hose particularly if it doesn’t directly fit to the garbage disposal or drain pipe.
- Now connect the drain hose to the dishwasher and the garbage disposal or drain pipe. Make the connection secure using the fittings or clamps.
- Finally, turn on the dishwasher and check the hose to make sure it is working properly.
Potential Consequences of Shortening Dishwasher Drain Hose
You shouldn’t decide to shorten the drain hose in the attempt. If you can’t install an air gap or don’t have enough space for applying a high loop, then shortening the drain hose can be your way to go. The reason is that shortening the drain hose can cause the dishwasher to suffer from blockage. So you may need to pull the hose out and clean it more often. A bit of extra length can help you avoid these issues.
If the dishwasher drain hose is too long, loop it up to the sink base’s top. The drain hose will function properly. It won’t let the dirty water sink drain from the siphoning to the machine.
A dishwasher’s pump is usually designed to pump 1 ½ meters. Shortening the drain hose can be beneficial and won’t hurt the pumping as long as its highest point remains over the outlet and the machine’s water level.
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Frequently Asked Questions :
1. What is the maximum length of a dishwasher drain hose?
The dishwasher’s drain hose shouldn’t be more than 10’ in length while most manufacturers provide a 6 feet hose. Too long a drain hose can cause backflow of wastewater and damage the drainage system too early. The diameter of the most drain hose is ½ inches.
2. Are dishwasher drain hoses universal?
No, the length of the dishwasher drain hose varies depending on the manufacturing company. So if you want to purchase a new hose, make sure it has the desired length and fits with your machine.
3. Where should you cut a too-long drain hose?
Whether you want to cut a too-long hose to shorten it or fit with an airbag, choose the loose end. Then use a hose clamp to secure the connection between the hose and the air gap fitting.
Too long a dishwasher drain hose isn’t a concerning issue as long as you can handle it properly. So, high loop the drain, install an airbag, or cut the extra length. If you don’t want to experience these hassles, replace the lengthy hose with a flexible one.
Then extend or shorten the drain hose as required. However, make sure the new hose is compatible with your dishwasher and all your adjustments meet the local plumbing codes.