Quick answer: Fixing a running toilet yourself costs $5–$25 in parts. Hiring a plumber typically runs $75–$200 depending on the cause and your area. Since the usual fix is a $10 flapper or a $15 fill valve, this is one of the best repairs to DIY.
If you are not certain it is the flapper or the fill valve, diagnose it by symptom first so you buy the right part once.
DIY Cost Breakdown
| Fix | Part cost | Time |
|---|---|---|
| New flapper | $5–$12 | 10 min |
| New fill valve | $10–$20 | 15–20 min |
| Full tank rebuild kit | $20–$35 | 30 min |
Plumber Cost
A plumber usually charges a service call ($75–$150) plus parts. For a simple flapper or fill valve, expect $75–$200 total. Complex issues (cracked tank, supply problems) cost more.
Should You DIY It?
Almost always yes — a running toilet is the most beginner-friendly plumbing repair. Our complete running-toilet guide walks through each fix step by step.
What Affects the Price
Three things move the number: the cause (a flapper is cheaper than a full valve replacement), your region’s labor rates, and whether it’s an emergency/after-hours call. In a high cost-of-living area a plumber’s minimum service call alone can be $100–$150 before any parts.
How to Save the Most
The flapper and fill valve are the two cheapest, most common fixes and both are genuinely beginner-friendly — no special tools, about ten minutes each. Watching the tank while it runs tells you which one to replace (water into the bowl = flapper; water into the overflow tube = fill valve). Our complete running-toilet guide walks through each fix with the exact part to buy.
When Paying a Pro Makes Sense
If the toilet is old and you’re chasing repeated failures, a full tank rebuild (or a new toilet) may be the smarter spend than fixing one part at a time. And if the leak is at the base rather than inside the tank, that’s a wax-ring/flange job — messier, and worth a plumber if you’re not comfortable pulling the toilet.
FAQ
Is it worth fixing a running toilet myself?
Yes — it’s usually a $10 part and 10 minutes, versus $75–$200 for a plumber. It’s the most DIY-friendly plumbing repair.
How much water does a running toilet waste?
Up to 200 gallons a day, which can add $20–$100+ to a monthly water bill — so fixing it fast pays for itself.
What’s the most common cause?
A worn flapper that no longer seals, followed by a faulty fill valve or a float set too high.
🔧 Plumber-Recommended Parts & Tools
Tackling this yourself? See a licensed plumber’s picks for the best fill valves and tank repair kits — the parts that get the job done right the first time.
Fix the 12 Most Common Plumbing Problems Yourself — Free Plumber’s Handbook — including the toilet fixes plumbers charge $150+ for
Step-by-step fixes for the 12 most common problems — and exactly when to call a pro. Free and instant, from a licensed plumber. Save hundreds on calls you didn’t need.