One of the most frequent problems I am called on to solve at the apartment complex is toilets that turn on by themselves. The tenant will say, It keeps turning itself on.

Whats happening here is the toilet is slowly leaking around the seal of the flapper, and its draining the tank. In order to maintain the water level in the tank the toilet turns itself on, so you get this on and off again syndrome. Its easy to determine if this is the problem by looking into the toilet bowl. The water in the bowl should be calm and smooth, but if you see tiny little ripples of water then your flapper needs to be replaced.

So, how do you replace a flapper?

1. Reach down by the base of the toilet (on the outside of the toilet) and find the water supply to your toilet. Its usually on the left hand side. Slowly and carefully turn the faucet valve to the right. This will turn the water off. I say slowly and carefully because many of these faucets are old and cantankerous, and you dont want to spring a leak in your faucet.

2. Remove the lid of the tank and gently set it someplace out of the way. Sit down on the toilet seat facing the tank. Youll notice that the handle for flushing the tank is attached to a bar that runs above the water line to about the center of the tank. At the end of this bar is a chain that runs down into the depths of the tank and is attached to the flapper. This is where your problem is. If you press down on the flapper you may be able to stop the leaking. (Ive tried cleaning them off where they seal, so as not to have to replace them, but I havent had any luck with this, so I always replace them with a new flapper).

3. Your hard plastic flapper is removed by gently lifting up on the ears that are attached to the pegs on the pipe that your flapper is attached to. If your existing flapper is a soft rubber type then pull the ears off of the pegs from the side. Remove the flapper and detach the chain from the handle bar.

Now heres some good news. The cheapest flappers work the best. The ones I use are blue and made of soft rubber. (They cost around $3). Even if your flapper is made of hard plastic it can be replaced with a soft blue rubber one, and if your old flapper had a flotation device on the chain you dont have to use it on the new flapper. Just the chain and the rubber flapper are all you need.

4. Reattach the flapper ears to the pegs at the base of the pipe and reattach the chain to the handle bar. (A new chain comes with each new flapper). When you reattach the chain leave a little slack in it so that the flapper easily closes all the way, but you dont want to leave too much slack or it wont pull the flapper up enough to drain the water out of the tank, and youll get an abbreviated flush. The way to get the correct balance is to experiment flushing the toilet over and over, and readjusting your chain length.

5. Turn your water back on slowly and gently. Dont put any more strain on these old pipes and threads than is necessary. Let the tank refill and then try flushing. Your flapper should open, stay open for a few seconds and then as the water in the tank drains about two thirds of the way the flapper should plop back down and seal the hole. Its magic.

6. The chain length adjustment is sometimes tricky to achieve, but I assure you it does exist. Also you may have to move your chain on the handle bar to one of the different slots. On the handle bars there are three different holes you can put the chain through to perfect your adjustment. A combination of the correct slack in the chain and the positioning on the flush bar are going to bring you the results you want. Each toilet is unique in its requirements for balancing the chain length.

Flush the toilet and look into the bowl. After a minute or so the water should settle down and be as still and placid as a pond. If after several minutes you continue to see ripples your flapper is still not sealing well. If this occurs try cleaning off the lips of the base where the flapper seats itself. Readjust your chain so theres more slack and try flushing it again.

Youll get it.

In review, here are the seven steps to replacing your flapper:

1. Shut water off.

2. Remove lid from toilet tank.

3. Remove flapper, chain and float from handle bar.

4. Install new flapper and connect chain to handle bar.

5. Turn water back on.

6. Test flushing. Make adjustments to chain length and location if necessary.

7. Check water in bowl to make sure there are no ripples.

From 'The Property Manager' by Jim Muckle