Replacing the wax ring seal under your toilet is one of those jobs that sits right on the boundary between DIY and licensed plumbing work in New Zealand. The short answer is: yes, in most cases a homeowner can remove and refit their own toilet, but there are important legal limits you need to understand before you pick up a spanner.
What Does a Wax Ring Do?
The wax ring (sometimes called a wax gasket or closet flange seal) sits between the base of your toilet pan and the closet flange — the fitting that connects the toilet to the soil pipe in the floor. It creates a watertight, gas-tight seal that stops sewer gases and waste from escaping into your home. Over time, wax rings can fail due to age, a rocking toilet, or a floor that has shifted, leading to leaks, bad smells, or water damage around the base of the pan.
Is It Legal for a Homeowner to Do This in NZ?
Under the Plumbers, Gasfitters and Drainlayers Act 2006, most plumbing work on sanitary fixtures must be carried out by a licensed plumber. However, there is a specific exemption that allows a homeowner to remove and refit their own toilet on an existing, properly installed flange — provided no alterations are made to the soil pipe, drain connections, or flange itself.
In plain terms:
- ✅ You can do: Lift the toilet, swap the wax ring, and refit the toilet to an existing flange in good condition.
- ❌ You cannot do: Alter, repair, or replace the closet flange; extend or modify the soil pipe; or carry out any other work on the drain or waste system. That is restricted work requiring a licensed plumber.
If you are unsure whether your job falls within the exemption, contact the Plumbers, Gasfitters and Drainlayers Board for clarification before starting.
What You'll Need
Tools and materials:
- Adjustable wrench or spanner
- Putty knife or scraper
- Rubber gloves and old towels or rags
- Bucket and sponge
- New wax ring (available from Bunnings or Mitre 10 — choose the correct size for your pan collar diameter)
- New closet bolts (T-bolts) if the old ones are corroded
- Silicone sealant (optional, for the base perimeter)
Step-by-Step: Replacing the Wax Ring
1. Turn Off the Water Supply
Locate the isolating valve on the wall or floor behind the toilet and turn it off. Flush the toilet to empty the cistern, then sponge out any remaining water from the pan and cistern.
2. Disconnect the Water Supply
Unscrew the flexible hose connecting the cistern to the isolating valve. Have a towel handy for drips.
3. Remove the Cistern (if close-coupled)
If your cistern sits directly on the pan, undo the bolts underneath and lift it clear. Place it somewhere safe.
4. Remove the Pan
Pry off the plastic caps at the base of the pan to expose the closet bolts. Undo the nuts, then gently rock the pan from side to side to break the old wax seal and lift the pan straight up. Plug the open flange with an old rag to block sewer gases while you work.
5. Clean the Flange
Scrape away all old wax from the flange and the pan horn using your putty knife. Inspect the flange carefully — if it is cracked, broken, or corroded, stop here and call a licensed plumber, as flange repair is restricted work.
6. Fit the New Wax Ring
Press the new wax ring onto the pan horn (wax side facing away from the pan), or place it wax-side-up on the flange — follow the manufacturer's instructions. Insert new T-bolts into the flange slots.
7. Refit the Pan
Remove the rag from the drain. Lower the pan carefully, aligning the bolt holes with the T-bolts, and press down firmly with your body weight to compress the wax. Do not lift and reposition once seated — this breaks the seal.
8. Secure and Reconnect
Hand-tighten the nuts onto the T-bolts, alternating sides, then snug them up with a spanner — do not overtighten or you risk cracking the pan. Refit the cistern, reconnect the water supply, and turn the isolating valve back on. Check for leaks before replacing the caps.
Tips for a Good Result
- Never reuse an old wax ring — always fit a new one.
- If your floor has been retiled and the flange now sits below the finished floor level, you may need a wax ring with an extension horn or a flange extender kit — but fitting a flange extender may constitute restricted work, so check with a plumber first.
- A toilet that rocks after refitting will quickly destroy a new wax seal. Use plastic shims to stabilise the pan before tightening.
- The MBIE Building Performance website has useful guidance on what work requires consent and licensing.
When to Call a Professional
Call a licensed plumber if you find any of the following:
- The closet flange is cracked, broken, corroded, or at the wrong height
- The soil pipe or drain connection needs any alteration
- There is evidence of subfloor water damage or rot (you may also need a builder)
- You are not confident working around sanitary drainage
Sewer gas contains harmful substances, and a poorly sealed toilet can cause ongoing moisture damage — it is worth getting it right. You can find qualified, local plumbers on tradedirectory.co.nz.
Safety Note
Always wear rubber gloves when handling toilet components and old wax. Wash hands thoroughly afterwards. Keep the drain opening plugged with a rag while the toilet is removed to prevent sewer gases — which can include methane — from entering your home. See WorkSafe NZ for general guidance on working safely in confined or odour-affected spaces.
Master Plumbers
