Knowing how to install a wax ring can save you time, money and a potentially messy problem in the future. Putting a new wax ring on when the toilet is removed is an easy job. If you need to pull the toilet up just to change the wax ring it is more of a job.
Purchasing a Wax Ring
The first thing you are going to need is a new wax ring. Most of the time, you want to get one with an integral plastic flange, similar to an Harveys No Seep #1, this is a very popular wax ring that costs less than $5.
There are other wax rings that do not have the added flange. Generally, the only time you would want those is if you have built up the floor and not raised the toilet floor flange. In this case, a single wax ring may not be thick enough for a seal. When this happens you may need to add another ring without a flange, similar to a Harvey's Bol-Wax #1. This will offset the added depth from the new flooring.
Removing the Toilet
Removing a toilet is a job in itself. You need to drain the toilet, shut the water off and then remove it from the floor.
The article 'Removing a Toilet' has step by step instructions for how to remove the toilet without making a big mess.
Removing an Old Wax Ring
Before you can replace the wax ring you need to get rid of the old one. Have a trash bag ready and use a scraper to clean the wax off of the flange. Tilt the toilet up and see if there is any residue from the old ring on the bottom of the toilet. Scrape it off as required. This is the part that makes a toilet flange repair a less than desirable job. The old wax ring is going to be a kinda of nasty. The picture gives you the idea. Just get rid of it as fast as you can. Admit it, it's one of the nastiest things you've ever seen. You might want to consider wearing gloves.
New Anchor Bolts
You may have had some trouble with the anchor bolts when you removed the toilet. This is a common problem and many time a hack saw is involved and the bolts are ruined.
Even if you got them loose with a wrench, it is a good idea to replace them. They only cost a couple of dollars and they are not know for longevity. See the article on 'Replacing Toilet Anchor Bolts' for instructions and best practices. It is a good idea to double nut them, which is described in this article.
Installing the New Wax Ring
Most plumbers will install the wax ring on the bottom of the toilet prior to setting it back in place on the flange. The wax ring needs to be located correctly on the bottom of the toilet. Placing the wax ring on the flange first may result in poor alignment and potential leaks.
Press the new wax ring onto the bottom of the toilet around the opening. Set the toilet up on a couple of wood blocks until you set it back in place. For most installations a single wax ring with a flange on it will work fine. If multiple floors have been installed and the flange seems to be sunken below the floor, you may need to add an extra ring without a flange. You would not want this toilet flange repair to fail because the wax ring would not seat.
Replacing a wax ring is no big deal once you have the toilet removed. Hopefully you did some extra maintenance while the toilet was up, like replacing the anchor bolts.