Low-Flow Toilet Problems: Understanding the Pros and Cons

Households can use 300 gallons of water daily, and a quarter of that comes from flushing the toilet. Low-flow toilets use less water per flush than standard toilets and can help households reduce water consumption. While they’re an excellent choice for the planet, low-flow toilet problems may mean they’re not right for your home—they clog more often and can cost more to install. Review the pros and cons of low-flow toilets before making your decision. 

What Is a Low-Flow Toilet?

Low-flow toilets use 1.28 gallons per flush (gpf), which is lower than the federal requirement of 1.6 gpf, and some models use even less water. This type of toilet can help homeowners conserve water and save on their water bills. While they’re the toilet of choice for the environmentally conscious—and some states even require them—homeowners should weigh the pros and cons of these toilets, especially if they have a busy household. 

How Do Low-Flow Toilets Work?

Low-flow toilets combine clever design and mechanics to flush more efficiently. Instead of relying on a large influx of water to clear the bowl, they use targeted water force and direction to do the same job with less water. Most modern low-flow toilets have efficient bowl shapes, steeper trapways, and carefully placed siphon jets to help move waste quickly and cleanly. 

There are two main types of flushing systems in low-flow toilets: gravity-assisted and pressure-assisted. Both meet low-flow standards, so the best one for your home depends on your plumbing setup, noise tolerance, and desired flushing power.

Gravity-assisted toilets are the most common low-flow option and use the weight of the water from the tank to flush. They’re quieter and have fewer moving parts, so they’re easier to maintain. Pressure-assisted toilets have a sealed tank that traps air and builds pressure with each refill. When you flush them, the pressurized air pushes the water out of the storage tank with extra force. These low-flow toilets are better at clearing waste in one go, but they’re louder and can cost more. 

Pros of Low-Flow Toilets

Low-flow toilets offer cost savings and water conservation for the environmentally conscious homeowner. A toilet installer can help determine if this is the right type of toilet for your home. 

1. Conserves Water

When you flush the toilet, water rushes from the tank through the holes beneath the rim and the siphon jet hole across from the drain hole. This rush of water whisks waste through the pipes and into the sewer system or septic tank. 

Low-flow toilets release less water per flush than a standard toilet, reducing your household's water use. Households can reduce toilet water use by 20% to 60% each year by installing WaterSense-labeled toilets, which can use as little as 0.79 gpf. WaterSense is a program sponsored by the U.S. Environmental Protection Agency (EPA).

2. Saves Space

Low-flow toilets use less water, so they can have a smaller tank and offer a more streamlined appearance. This is firmly in the pro column for those with bathrooms on the smaller side. Depending on your bathroom layout, you can carve out a little extra storage space with a smaller toilet. 

3. Reduces Water Bills

The EPA estimates that 24% of daily water usage is spent on flushing toilets. A low-flushing toilet is more environmentally friendly but could also save you money on your water bill, so the installation could pay for itself over time. 

Cons of Low-Flow Toilets

Low-flow toilet problems stem from the low flow of water. While it may sound counterintuitive, the low flow may have trouble clearing all the waste down the drain and through the pipes, resulting in clogs, smells, and repairs. Speak with a toilet installer who can help determine if this toilet is right for your bathroom. 

1. Clogged Pipes

Because low-flow toilets don’t push as much water through the pipes, they’re not as effective at eliminating waste. This means you may have to deal with the toilet clogging more often than with a standard toilet. To remedy the issue, you can try DIY repairs for common toilet problems or a double flush, but that defeats the purpose of having a low-flow toilet.

2. Sewage Smell

If enough waste gets backed up in pipes, smelly odors can build up and float back into your home. If you have a busy home and often host visitors, a low-flow toilet may not be the right choice, and you may have to pay for extra plumbing and toilet repair costs.

3. Higher Installation Costs

A low-flow toilet might not be compatible if you live in a home built before the mid-1980s with older plumbing. Because older toilets used so much water to flush waste, the plumbing didn’t require the same careful positioning as it does for newer, low-flow models. You can still make it work with some plumbing modifications, but it will add to the total cost of installing a toilet. 

Keep in mind that DIY installation is more difficult with a low-flow model than with a standard toilet. If you have a newer home, this may not be a concern, but check with your plumber to be sure. 

Maintenance Tips to Avoid Common Low-Flow Toilet Problems 

Toilet issues can quickly ruin a good day, so to avoid common low-flow toilet problems, follow these maintenance tips:

• Use less toilet paper: Using a lot of toilet paper can strain the toilet’s ability to flush it away. Paying attention to how much toilet paper you use and possibly reducing the amount can help prevent clogs. Installing a bidet is one way to save on toilet paper. 

• Keep it clean: Because the toilet already uses less water than a standard model, make sure the water flows freely from the holes under the rim. To do this, clean the toilet regularly and get under the rim. You can use a mirror to get a good look and scrub problem areas with an old toothbrush.

• Double flush if necessary: While double flushing every time counteracts the water conservation powers of a low-flow toilet, you can double flush occasionally if you’re flushing more waste than usual.

Alternatives to Low-Flow Toilets

The current federal standard for the amount of water toilets use is 1.6 gpf. This is much less than the average 5 to 7 gpf for toilets installed before 1982. So even if you don’t choose a low-flow toilet or can’t install one, you still use less water with today’s standard toilets than with older models. When the time comes to replace your toilet, alternatives to low-flow toilets include:

• Washdown: A washdown toilet has a wider trapway and larger drain hole than standard toilets, and it’s also more compact. This style uses water's gravitational force to wash waste down the drain.

• Siphon flush valve system: This is the type of toilet you most commonly encounter. It has a curved tramway, and water rushes from the tank through holes below the rim and from the siphon jet hole.

• Dual flush: If you’ve seen a toilet with two buttons for flushing, you’ve seen a dual-flush toilet. This style gives users an option for solid and liquid waste, with the former using more water than the latter.

• Pressure assist: Pressure-assist toilets are common in commercial applications, but homeowners who need extra power can benefit from the pressurized air tank that forces water through the pipes in a powerful rush.

Is a Low-Flow Toilet Right for You?

If you want to save money and conserve water, a low-flow toilet might be the right choice for you, but be sure to consider the risk of clogged pipes and foul odors that can occur when the flow isn’t sufficient to push the waste through the pipes. If you have a lot of people in your household or entertain frequently, you may want to pass on a low flow in favor of a more forceful flush. You can also ask a toilet installer near you for recommendations based on your specific circumstances.