eco-friendly toilets

Living Green – Can Eco-Friendly Toilets Cause Plumbing Problems?

February 21 2018

Eco-Friendly Toilets

For those who have embraced the green living trend, eco-friendly toilets (aka low flush toilets) may seem like a great option all round. After all, they’re more cost efficient and use less water than traditional toilets.

Replacing an old toilet with an eco-friendly toilet can easily cut your toilet’s water usage by 20-60%, according to the Environmental Protection Agency. And, most importantly, they help conserve the world’s limited water supply.

But unfortunately, the benefits of eco-friendly toilets don’t come without potential downsides. Can eco-friendly toilets cause plumbing problems? In certain circumstances, yes; we’ll be covering what some of those circumstances are here. See our blog on toilet fill valve problems if you’re experiencing trouble with your water tank.

The GPF Factor

First of all, most of our current water and sewage pipes were made to work with toilets with a GPF (gallons per flush) rating of 3.5 or more. In some cases with eco-friendly toilets, the flush won’t be strong enough to push the waste far enough down the pipes. This will result in a buildup of waste in the pipes. Even if the pipes don’t clog up, sediment will build up and corrode the pipes over time. Also, if your pipes are in need of repair, there is a good chance they’ll become even worse with eco-friendly toilets; therefore, your pipes should be checked and fixed prior to installing eco-friendly toilets.

Negative Pipe Sloping Causes Eco-Friendly Toilet Plumbing Problems

Eco-friendly toilets may cause plumbing problems if the drains slope too much.

If you have an older house, or a house that wasn’t built properly, there may even be a “negative slope”, which means that the water will just stand in the pipe. With negative pipe sloping, waste is only carried away by the sheer force of the gallons of water that is typical from older toilet models.

So, if you have older cast iron pipes with sludge built up in them, you can expect plumbing problems to occur.


To avoid these potential problems, you should consider upgrading your pipes. This can be a smart decision when installing newer model toilets.

For the piping upgrade, consider PVC pipes; they’re better for dealing with the reduced flow of eco-friendly toilets.

If you have aging cast iron pipes and you don’t want to upgrade, you may want to install a pressure-assisted toilet. This type of toilet powers flushing with pressurized air from within the toilet tank. Keep in mind that this is a noisier and more expensive toilet. However, it typically requires less maintenance.

Also be sure to consult with a plumber to see if your house has sufficient pressure to operate an eco-friendly toilet. If house pressure is too low, the eco-friendly toilets may not work as expected.