Can You Wet Vent a Saniflo System (Complete Guide)

When it comes to toilet vents for homes with interconnected bathroom fixtures, you’ll need to think outside the box. Plumbing codes generally dictate that all fixtures with traps must have a vent, and the Saniflo system is no exception to this rule. That brings us to today’s big question: can you wet vent a Saniflo system?

You can wet vent a Saniflo system in adherence to your area’s plumbing codes. Saniflo systems need to be vented like all other bathroom fixtures. Wet venting plays two essential functions: draining waste while letting out odors. The vent also helps keep the pressure balanced in the drainage system.

Saniflo systems are great home additions because they don’t require much maintenance. In this short guide, we explain everything you need to know about wet venting a Saniflo system so it functions as efficiently as possible.

repairman in uniform examining part of pipe in toilet

What Is Wet Venting?

Before we examine whether Saniflo systems can be wet-vented, it is important to point out that wet venting connects the drain pipe to the vent pipe. 

To put things into perspective, wet venting uses one pipe to vent out sewer gases to the outside environment and drain wastewater from the toilet at the same time. The same pipe that vents out sewer gases drains wastewater into the main drain line.

Wet venting isn’t as complicated as it may appear to be. But just to be on the safe side, we’ve compiled these standard guidelines handpicked from the National Plumbing Code and the Uniform Plumbing Code:

  • All the fixtures that are being wet-vented together must exist on the same floor. For instance, you cannot wet vent a bathroom and a toilet on different floors. Doing this is against the plumbing code, and your project may not be approved by the construction inspector until the issue has been corrected.
  • The wet vent pipes must be able to take the hydraulic load you throw at them. For instance, two fixture units should not be wet-vented by a 1.5″ (38.1 mm) pipe. The minimum size allowed for an individual vent diameter should not be less than 1.25 inches (31.75 mm).
  • When venting, keep your toilet at a lower level than the other fixtures using the same vent to reduce the risk of toilet waste flowing into the vent.
  • Horizontal wet venting is permitted for any combined fixtures in the same bathroom in the same room.

These codes apply to bathroom fixtures such as lavatories, sinks, tubs, and showers. Take note of the size of your pipes. Your trap and vent should be 6 feet apart (or less) to function properly.

Does Saniflo Need To Be Vented?

So now that you know the answer to can you vent a Saniflo system, let’s consider – do you need to vent a Saniflo? 

Saniflo toilets need to be vented to let the sewer gases out of the system. The macerator toilet manufacturer insists that all Saniflo products must be vented to the main vent with a 1-1/2 inch (25.4 – 12.7 mm) vent pipe. 

The only exemptions from this rule are the self-contained Sanicompact 48 and Sanistar models

plumber working in the restroom

What Happens When You Don’t Vent?

A Saniflo that doesn’t work is a nightmare for both plumbers and homeowners. Failure to vent your Saniflo cripples its proper functioning. 

  • In severe cases, the system may eventually back up and overflow, which can cause a huge mess and waste your time and effort in cleaning up the mess.
  • Failure to vent your unit may cause the emission of an unpleasant odor into your home. If methane and other sewer gases leak into your home, it could pose some serious health risks and potential fire hazards.
  • The absence of a properly equipped ventilation system could also cause wastewater to drain at a slower rate.
  • Lastly, you may have to deal with the annoying gurgling noises when someone walks into the bathroom in the middle of the night.

Wet venting has several benefits. For starters, you can save on the cost of new venting pipes, time, and labor. If you choose to go this route, be sure to check with your contractor and follow their recommendations for the best installation.

That said, wet venting is not always recommended for Saniflo systems, especially where bad odors are a menace that doesn’t seem to go away. Dry venting is ideal, as it only allows air through the vent pipe. The vent should extend at least 1 foot above your roofline so that it runs clear of obstruction. 

Wet Venting a Saniflo System

As mentioned before, dry venting is usually recommended for Saniflo systems. With dry-venting, wastewater does not share the same path with the air. 

The vent pipes to be used should measure between 1-1 ½ inches (25.4 – 38.1 mm) in diameter. PVC, CPVC, and copper pipes are recommended for Saniflo systems.

Below are a few tips to help guide you when venting your Saniflo toilet through the roof. Please note that these steps vary by the installer and the plumbing codes in your area.

You will need a screwdriver:

  • Teflon tape
  • A drill
  • Plumbers tape
  • Hacksaw
plumbing repair tools

The steps:

  1. Find the perfect spot to install the vent pipe. This spot should be directly above the drain pipe you are venting.
  1. Position your drill perpendicularly to the ground when drilling on a slanting roof.
  1. Fit the roof boot. Sometimes the pipe may not fit perfectly in the hole you’ve drilled and may leave some gaps. Installing a roof boot that covers the vent hole and the surrounding area will prevent rainwater from leaking into your house. 
  1. If your roof has shingles, you will need to cut around the hole with a hook blade. The boot will then fit beneath it.
  1. Finally, insert your vent pipe. Be sure to check the recommended guidelines for your area to avoid any setbacks.  

Ensure that the vent pipe is installed correctly and sealed. Leakages in the vent may affect the system’s efficiency. Also, ensure that the vent pipe stands upright and away from nearby heat sources.


Before venting your Saniflo system, turn off the power to the unit and cut off its water supply. You also want to make sure you have emptied the sink and removed any dirty dishes and towels before wet venting. This will provide a clear working space for your project.