Plumbing Repairs You Shouldn't DIY (and the Ones You Can)
By Mike Holt, NJ Master Plumber · June 15, 2024 · 3 min read · Updated November 1, 2026
Quick answer
Leave gas lines, hands-on water heater work, main sewer line clogs, burst or hidden leaking pipes, and moving fixtures to a licensed plumber. These jobs involve gas, scalding water, sewage or water damage, and most need a permit in New Jersey. Small jobs like clearing a sink clog, replacing a flapper or cleaning an aerator are fine to do yourself.
Want us to take a look? We find the cause and give you written upfront flat-rate pricing options before any work starts.
A lot of plumbing is fine to fix yourself, and our how-to guides walk you through those jobs step by step. Some jobs aren't. They involve gas, scalding water, sewage or hidden leaks, and a small mistake can turn into a big repair.
Which plumbing repairs should you never DIY?
| Job | Why it's a job for a licensed plumber |
|---|---|
| Gas line repairs or new gas lines | A leak can cause a fire or explosion; gas piping is pressure tested and needs a permit |
| Water heater installation | Gas, venting, a relief valve and scalding water; a permit is usually required |
| Water heater flushing, anode rods and expansion tanks | Scalding water, stored pressure, and electrical or gas controls |
| Main sewer line clogs | Sewage exposure, and rental machines can break or jam in the line |
| Burst or hidden leaking pipes | Water damage spreads fast inside walls and ceilings |
| Moving or adding fixtures | Drain slope, venting and a permit in New Jersey |
| Repiping or replacing a water service line | Shutting off the main, permits and code-approved materials |
If you're not sure whether a job needs a permit, our guide to NJ plumbing codes lists the common ones.
Not all of these are jobs we take on. We don't do outside digging or excavation, and we don't work on outside grill, fire pit or generator gas lines or on fireplace lines. For repiping, contact us to confirm whether we handle your scope and materials.
Why are gas lines and water heaters off limits?
Gas work is the clearest line. A loose fitting or the wrong connector can leak gas into the house, and a badly vented water heater can push carbon monoxide inside. Water heaters also store water hot enough to scald, under pressure, with a relief valve that has to be piped correctly to be safe. See our gas line and water heater services.
If you smell gas, leave the house first. Don't flip switches or use your phone inside. Call your gas utility or 911 from outside, and don't go back in until they clear it.
Why not snake the main sewer line yourself?
A clogged sink is one fixture. A main line clog backs up every drain in the house, usually into the lowest one first. Rental drum machines are heavy and can kink, whip or leave a broken cable in the line. The cause is often roots or a damaged pipe, which a snake doesn't fix. Our guide to a sewer backup in the basement covers what to do while you wait for help.
What about burst pipes and hidden leaks?
Shut off the main water valve, then call. A pipe that burst once is often weak in other spots, and water inside a wall or ceiling keeps spreading after you stop seeing it. The burst pipe guide has the first steps, and leak detection finds water you can't see.
Which plumbing repairs can you do yourself?
These are reasonable jobs for most homeowners, and we have step-by-step guides for each:
- Unclogging a toilet or a drain with a plunger.
- Fixing a running toilet with a new flapper or fill valve.
- Fixing a leaky faucet.
- Cleaning a garbage disposal.
Each guide has a "stop and call us if" list. If you hit one of those, or a part won't come loose, stop there.
Plumbing Doctor handles many of the jobs that shouldn't be DIY across Central New Jersey, under NJ Master Plumber Lic. #36BI01345600. Written upfront flat-rate pricing options. You choose. The $49 service call covers the trip and is waived if you go ahead with the work. Outside regular hours, emergency service requires a $250 upfront emergency fee. When paid, the standard $49 service fee is waived. During regular hours there is no emergency fee. Additional repairs are quoted before work begins. We respond immediately upon contact; dispatch and arrival depend on availability and location. Call 908-873-6686.
Get tips and reminders
New guides and seasonal reminders. A few emails a year.
Stop and call us if
- You smell gas. Leave the house first and call your gas utility or 911 from outside.
- Water is coming through a ceiling or wall, or you can't find the leak.
- Several drains back up at once, or sewage comes up in the lowest drain.
- The water heater is leaking, or the relief valve keeps opening.
- A DIY repair didn't hold, or you've already tried twice.
Call 908-873-6686.
Michael Holt
Owner and operator of Plumbing Doctor, NJ Master Plumber (Lic. #36BI01345600) and U.S. Marine Corps veteran.
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