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.
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.