How to Replace a Toilet
Replace an old or broken toilet in an afternoon - no plumber needed for a like-for-like swap.
Difficulty
Medium
Time
2-3 hours
Cost
£80 - £350
Before You Start
Turn off the water supply at the isolation valve behind the toilet or at the mains stopcock. Flush the toilet and sponge out remaining water from the cistern and bowl. Wear rubber gloves throughout. Have old towels ready for spillage. The old toilet will be heavy - get someone to help you lift it.
Replacing a toilet is less daunting than it sounds. If you are doing a like-for-like swap (same type, same position), it is a straightforward job. A close-coupled toilet (where the cistern sits directly on top of the pan) is the easiest type to install. The trickiest part is getting a good seal on the soil pipe connection - modern flexible pan connectors make this much easier than the old rigid ones.
What You Will Need
Tools
- - Adjustable spanner
- - Hacksaw (if old bolts are seized)
- - Spirit level
- - Bucket and sponge
- - Screwdriver set
- - Silicone gun
Materials
- - New toilet (close-coupled is easiest for DIY)
- - Flexible pan connector
- - New isolation valve (recommended)
- - Flexible fill hose
- - Silicone sealant
- - Floor bolts and caps
- - PTFE tape
Step-by-Step Instructions
Turn Off and Drain
Close the isolation valve on the water supply pipe behind the toilet. Flush the toilet to empty the cistern. Sponge out any remaining water from both the cistern and the bowl into a bucket.
Disconnect the Water Supply
Unscrew the flexible fill hose from the base of the cistern. Have a towel ready to catch drips. If the fill hose is old or rigid, now is a good time to replace it with a new flexible braided hose.
Remove the Old Toilet
Unscrew the floor bolts holding the pan to the floor. If they are corroded and will not move, use a hacksaw to cut through them. Gently rock the pan to break the old seal, then lift straight up and off the soil pipe. Stuff a rag into the soil pipe to prevent sewer gases escaping.
Clean the Area
Scrape away old sealant and wax from the floor and around the soil pipe. Clean the floor thoroughly. This is also a good opportunity to repaint or re-tile the floor area that was hidden under the old toilet.
Fit the Pan Connector
Push the flexible pan connector onto the soil pipe outlet. These rubber connectors flex to accommodate slight misalignment between the new toilet and the existing pipe position.
Position the New Toilet
Remove the rag from the soil pipe. Offer up the new pan and push it firmly into the pan connector. Check it is straight with a spirit level. Mark the floor bolt positions through the holes in the base, then drill and plug the holes. Secure with the bolts - tighten until snug but not overly tight as you can crack the ceramic.
Fit the Cistern
For a close-coupled toilet, place the doughnut washer over the flush valve outlet on the bottom of the cistern. Lower the cistern onto the pan and secure with the bolts provided. Tighten evenly on both sides.
Connect the Water and Test
Connect the flexible fill hose to the cistern fill valve. Apply PTFE tape to the thread. Turn the water supply on slowly and let the cistern fill. Check every connection for leaks. Flush several times and check around the base of the pan for any water seepage. Apply a neat bead of silicone around the base of the toilet where it meets the floor.
Pro Tip: Measure Before You Buy
Measure the distance from the wall to the centre of the soil pipe (the set-out). Buy a toilet with the same set-out or you will need to modify the pipework. In the UK, 200mm is the most common set-out.
Pro Tip: Replace the Isolation Valve
If the existing isolation valve is stiff or corroded, replace it while the water is off. A new quarter-turn valve costs a few pounds and makes future maintenance much easier.
Common Mistakes to Avoid
- - Not measuring the set-out distance before buying - the new toilet may not line up with the soil pipe
- - Overtightening floor bolts - ceramic cracks easily and then you need a brand new toilet
- - Not using a flexible pan connector - rigid connectors make alignment very difficult
- - Forgetting to check for leaks before sealing the base - trapped water leads to rot and smell
- - Siliconing all the way around the base - leave a small gap at the back so any leak shows itself rather than being hidden
When to Call a Professional
If you need to move the toilet to a different position, change from a low-level to wall-hung toilet, or if the soil pipe needs modifying, call a plumber. Also if you discover rotten floorboards around the old toilet - this needs proper repair before fitting a new one.