Will a Low-Flow Toilet Work In an Older Home?

Installing low-flow toilets is a great way to conserve water and reduce your water bill. By using about half the volume of water as a standard toilet, you can save around a gallon and a half of water per flush. That adds up to thousands of gallons of water saved every year.

Many states and municipalities now require low-flow toilets on new homes or when replacing a toilet when remodeling a bathroom. For most homeowners, the process is simple and straightforward, but what if your home is 50 years old or older? Can your plumbing system handle a lower flow toilet?

The key to whether a low-flow toilet will function in an older home is the waste drain pipe slope. The waste pipe beneath a toilet needs a slope of between 1/8-in. and 1/4-in. per foot for the water to carry solid waste to the sewer. If it’s too steep or not steep enough, the flow of water could allow waste to collect, causing a clog.

In some older homes the slope may not have been carefully planned. Since older toilets had plenty of flushing power with 3 gallons of water to work with, it may not have been a concern.

If you have an older house, here are some things to be aware of if you decide to install low-flow toilets.

1. If your current toilet backs up occasionally, even when solid waste isn’t being flushed you may have a clogged waste line. Have the waste and sewer line inspected prior to installing a low-flow toilet.

2. When the toilet is lifted off the floor for other maintenance, use a flashlight to check the drain for standing water in the waste line. Even if it’s just a small amount, it could be a sign that you have a negative pipe slope.

If you’re concerned that your older plumbing system may not be able to safely handle a low-flow toilet, consider installing a unit with a pressure-assisted flush that uses water pressure to charge a compressed-air tank inside the toilet tank. When flushed, it will use the compressed air to drive water out of the bowel fast, forcing it down the drain and into the waste line with enough force to remove solid waste.

Have questions about low-flow toilets? Call ABC Southwest Plumbing & Air Conditioning. We can help answer all your plumbing questions.