How to Repair a Toilet: Learn Why & How to DIY

Hopefully the biggest toilet problem you'll ever have is getting someone to deliver a roll of toilet paper to you when sitting on the throne. But toilets have lots of moving parts and get lots of use. That means you'll probably need to deal with at least one toilet problem in your life as a homeowner. So before you end up with a ridiculous bill from a plumber, you should really learn how to repair a toilet.

Yes, this invoice arrived in my inbox the other day. I'm in the process of moving to Florida and was on the auto train when I got a phone call from my tenant in Hampton, NH. The call wasn't about the toilets. The call was to tell me the hot water heater had exploded and there were several inches of water on the basement (finished) floor.

With sketchy cell phone reception, I called my husband for help. Because our normal plumber (solo) wasn't available, he called a larger plumbing company without doing any research … a big mistake! We needed a new hot water heater and thought the cost of the toilet repairs would be minimal because the plumbers were already in the house. Sadly this wasn't true and I guess, it's a common problem for most homeowners who don't do the proper due diligence before hiring a plumber.

This article provides an overview on the basic concepts you need to understand as you learn how to repair a toilet. At the end we summarize the best resources found online, to help you handle most problems yourself so you can avoid costly plumber bills like the one above, which is hard to justify!

How to Repair a Toilet: Anatomy of a Toilet

How often have you taken the top off the toilet tank and stared at all the parts hiding inside? Don't laugh as we've all done it countless times and fortunately, forget about it 5 minutes later. Sometimes all you need to do is jiggle the chain to get the flapper to fit snugly over the flush valve, to stop the water from running.

Sometimes the problem with your toilet is a little more complicated. The question then is should you try to repair your toilet yourself? For the confirmed do-it-yourself homeowner, the answer is easy. But if that's not you, then what? This article provides insight into the anatomy of a toilet, so you can decide if you want to learn how to repair a toilet … based on how easy or difficult the job will be.

Toilet repairs can be broken down into three areas:

• The toilet guts refer to everything inside the tank and that's where most of the problems occur. With little risk of water damage because everything is inside the tank, these repairs are worth trying to do yourself.
• The toilet tank connects to the bowl below and the supply line coming out from the wall. There's a little more risk here but it's manageable because it's easy to shut the water supply line off (read: Learn How to Shut Your Water Off).
• The entire toilet has to be removed to replace the flange and/or wax ring used to attach the toilet to the floor. This is where I ran into the most problems with my handyman business so I know there's more risk here. First you've got to be comfortable moving the bowl. Then you've got to know what you're looking at as there might be structural damage underneath the toilet or the flange was simply installed incorrectly.

Note: Most plumbers won't deal with structural issues like wood rot. If you suspect problems with the floor under the toilet, you might want to all a handyman instead of a plumber.

Rebuilding the Toilet Guts: Fill Valve, Flush Valve and/or Flapper

Congratulations on deciding to learn how to repair a toilet. We know things will be challenging at first but trust me, they will get easier and in a few years, you'll come to think of yourself as an expert in repairing your own toilets (and those of friends and family if the word gets out).

So where do you start?

My goal here is to take the mystery out of toilet repairs, with a few important tips on how to save time. I've also included links to some of the best videos and articles written by others with far more plumbing experience than I have. I'm simply a homeowner who's rebuilt a few toilets personally. Most of what I know is based on talking to my customers and technicians while running a handyman business in southern NH for eight years.

The inside of your toilet looks complicated and it is until you understand the two functions that the parts perform. You'll also be pleasantly surprised to learn that most of the toilet parts come pre-assembled saving you time, and helping minimize mistakes. But honestly, mistakes are really the best way to learn your way around a toilet so take your time and be patient (not one of my strengths).

• The fill valve is a lot smarter today with it's integrated float. So after you flush, the float, once it reaches a certain height, stops more water from flowing into the tank. This replacement toilet part also includes built-in height adjustment making it easy to install.
• The flush valve serves two primary functions. It moves the water from the tank into the bowl, when the toilet is flushed and directs excess water from the tank to the bow. Flush valves come in different sizes, from 2” to 4” depending on the toilet brand. The most common size is two inches.
• The flapper is attached to the flush handle which needs to move easily to get the job done correctly. The challenge with the flapper is buying the correct replacement so I love the advice in this video, How to Buy the Right Flapper Valve, to take your old flapper to the store so you can buy one that's identical.

Note: There are some differences with dual flush toilets which I've not addressed here.

Fluidmaster Complete
Toilet Repair KitFluidmaster Fill Valve
& Flapper  Repair KitFluidmaster Universal (2 in)
Flapper

How to Repair a Toilet: Problems Outside the Tank

With problems outside the toilet tank, there's a little more risk from water leaks. So you want to be really careful about inspecting your repairs when you turn the water back on and be prepared to shut the water off quickly. You also need to be comfortable removing the toilet tank, putting it down safely and then reinstalling it. This isn't difficult but a small slip can cause a crack and you'll have to buy a new toilet which happened to me more than once when running my handyman business.

The most common repairs outside the tank include:

• Failure of a seal where the toilet tank is connected to the bowl. The parts to replace this connection are included in Fluidmaster's Complete Toilet Repair Kit.
• Leak in the supply line that carries water to your toilet tank. When my downstairs toilet supply line failed, it wasn't the braided stainless steel that failed. The plastic nut that connected the supply line to the tank cracked and leaked. If you're confused by the different types of supply lines (copper, braided stainless steel, nylon and pex), this video on supply lines and connectors very helpful.

• The wax ring and/or flange used to attach the toilet bowl to the floor is sometimes responsible for a water leak. This is a common handyman project, when the toilet rocks because the flange isn't level and tight. The flange should be mounted on top of the finished floor (video to learn more about the flange height). A wax ring or one of the new, wax-free rings, sits on top of the flange and seals the gap between the flange and the bottom of the toilet.

Fluidmaster Thick Wax
Toilet Bowl Gasket with FlangeDanco HydroSeat
Toilet Flange RepairFluidmaster Wax-Free
Toilet Bowl Gasket

Resources So You Can Tackle Your Toilet Problems

Here are the recommended steps for learning how to repair a toilet:

• Learn how toilets work with a video from the Science Channel (less than 3 min).
• Learn the basic toilet components to recognize so you can learn how to repair a toilet … by reading this article.
• Identify the toilet problems you need to resolve using Fluidmaster's Toilet Repair Guide.
• Turn off the water supply to your toilet.
• Learn the steps involved in rebuilding a toilet tank, if your repairs involve the guts of the toilet. If you're a visual learner, follow the steps in the video, starting and stopping as needed.
• If you prefer reading step-by-step instructions with photos, this DIY Network article, How to Remove and Replace a Toilet, is perfect.
• Turn the water on and test for leaks right away (dry rag or paper towel). Be prepared to shut water off right away if you find any leaks as it's normal to have to tighten up a bolt just a tad more.
• Smile and congratulate yourself on a job well done!

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