Overview of the Job – Upgrading a Standard Toilet to a Smart Bidet Seat

At a property on Meredith Street in Mount Waverley VIC 3149, our team at Your Choice Plumbers was called out after the homeowner wanted to upgrade their ensuite with a customer-supplied TOTO D-Shape Washlet bidet seat.

These types of smart toilet seats are becoming more popular in Melbourne homes because they offer a much more advanced bathroom experience, including:

  • heated seating
  • bidet wash functions
  • automatic deodorising
  • built-in self-cleaning features

However, this type of upgrade is not as simple as attaching a new toilet seat. These systems rely on very specific water and power set-outs, and the internal components are far more sensitive than a standard toilet seat.

This is exactly the type of situation where homeowners start asking, “can a plumber install a TOTO bidet seat in an existing bathroom?” or “does a smart toilet seat need plumbing changes first?” As an experienced plumber Mount Waverley, we often find that premium bidet seat installations require careful preparation behind the wall before the final product can be installed properly.

Why the Existing Ensuite Setup Was Not Ready for the TOTO Unit

Once we inspected the existing toilet arrangement, two important issues became clear straight away.

The first was the water connection layout.

The existing toilet water supply was positioned on the right-hand side, which is typical in many local bathrooms. However, the TOTO template required the water supply to come from the left-hand side for the unit to fit and connect correctly.

The second issue was the home’s mains water pressure.

As part of our standard checks, we tested the pressure and confirmed it was running above the 500 kPa maximum referenced under AS/NZS 3500.

That was a major issue because excessive pressure can:

  • damage the internal valves of smart bidet seats
  • affect long-term reliability
  • void the manufacturer’s warranty
  • create premature failure in other appliances across the home as well

So before the TOTO could be installed, both the infrastructure layout and the system pressure had to be corrected.

Why Pressure Protection Was Critical for the Bidet Seat

We explained to the owner that high water pressure is especially important on high-end toilet seats and smart bidet systems.

Unlike a basic toilet connection, these units contain more delicate internal components and rely on controlled operating pressure to function properly.

This is something we often explain on pressure limiting valve and PRV installation jobs, because premium appliances and bathroom technology will not perform properly if the incoming water pressure is left too high.

That meant pressure correction had to be handled before the final TOTO seat was commissioned.

Installing Pressure Protection for the Whole Home

The first major step was to install a pressure reducing valve (PRV) at the water meter.

This brought the home’s incoming water pressure down to a safe and compliant level, which did two important things:

  • protected the new TOTO bidet seat
  • protected the rest of the home’s plumbing appliances and fixtures at the same time

That made the job more than just a toilet upgrade — it became a wider plumbing protection upgrade for the property as well.

Removing the Existing Toilet and Opening the Wall

To carry out the infrastructure changes required for the bidet seat, we first had to remove the existing back-to-wall toilet.

Once the toilet was removed, we gained access to the wall area needed to relocate the plumbing connection.

We then opened the plaster so the water supply could be re-routed to the correct side in line with the TOTO installation template.

This was a key part of the project because without moving the water point, the bidet seat could not have been installed properly or neatly.

Re-Plumbing the Water Supply to the Correct Side

With the wall open, we re-plumbed the toilet water supply from the right-hand side to the left-hand side exactly as required for the TOTO seat.

This ensured:

  • the new seat could be connected correctly
  • the hose routing stayed neat and concealed
  • the final installation looked clean and intentional rather than improvised

In premium bathroom upgrades like this, those hidden plumbing details make a major difference to the finished result.

Coordinating the Electrical Side of the Installation

Because the TOTO seat also required power, this was not a plumbing-only project.

We coordinated with a licensed electrician to install a permanent waterproof power point on the left-hand side so the seat could be powered safely and neatly.

This was an important part of the overall outcome because the owner wanted a clean integrated finish without visible loose cabling or non-compliant power arrangements in the bathroom.

Final Fit-Off and Commissioning the TOTO Washlet

After the plumbing changes, plaster repairs, and painting were completed, we returned to reinstall the toilet and fit the TOTO Washlet seat properly.

We then commissioned the unit and carried out the startup process to ensure:

  • the plumbing connections were secure
  • the water supply was operating at the correct protected pressure
  • the seat powered up correctly
  • the unit was ready for normal operation

All additional brassware and valves required for the project were sourced from Reece Plumbing Burwood.

Final Result and Client Outcome

The final result gave the homeowner:

  • a fully integrated TOTO Washlet bidet seat
  • corrected water supply layout
  • compliant pressure protection at the meter
  • hidden power and plumbing connections
  • a cleaner, more premium ensuite finish overall

The owner was very pleased that the whole process was managed properly from start to finish and that the new luxury bathroom feature had been installed in a way that protected both performance and warranty.

Compliance with Australian Standards

This case directly related to the pressure control requirements referenced under AS/NZS 3500, which requires residential water pressure to be regulated to a maximum of 500 kPa, together with the proper installation of plumbing connections serving bathroom fixtures and appliances.

In practical terms, this meant the smart toilet upgrade was not just about fitting the seat itself. The home’s pressure had to be brought under control, the water supply point had to be re-routed correctly, and the final installation had to be prepared so the bidet seat could operate safely and reliably.

All work carried out by Your Choice Plumbers is completed in accordance with the relevant plumbing standards so high-end bathroom upgrades are installed properly and protected from avoidable pressure-related failure.

Our Home Plumbing Experts Approach

As part of our Home Plumbing Experts approach, we focus on both repair and prevention.

We include our complimentary Property Protection Audit with plumbing services to help homeowners understand hidden risks like excessive water pressure, unsafe hot water temperatures, and ageing flexible hoses before they turn into emergencies.

Find out more about our pressure limiting valve and PRV installation services and leaking toilet services where toilet upgrades and plumbing protection are involved.

Looking for a Plumber in Mount Waverley?

If you’re upgrading to a smart toilet seat, renovating a bathroom, or want the plumbing and pressure setup done properly before fitting high-end bathroom fixtures, visit our Plumber Mount Waverley page to learn more about how we help local homeowners.