Three cold showers in a row will motivate you to call a plumber faster than almost anything else. But before you pick up the phone in a panic, take a breath. A water heater that’s not heating could be something as simple as a tripped breaker, or something as serious as a failing tank that’s about to flood your basement. The questions you ask your plumber determine whether you spend $150 on a quick fix or $3,000 on a replacement you didn’t actually need.
This guide walks you through exactly what to ask before, during, and after the plumber’s visit. You’ll also find pricing benchmarks, red flags to watch for, and money-saving tips that most homeowners never hear about.
Before You Contact a Plumber
Do these five things first. They’ll save you time on the phone and help your plumber diagnose the problem faster:
- Check that the circuit breaker or gas valve is actually on. (You’d be surprised how often this is the entire problem.)
- Look for leaks or rust around the base of the tank.
- Listen for strange noises: popping, rumbling, hissing.
- Note any discolored water or weird smells.
- Find your model number and the unit’s age (usually on a sticker on the side).
If you smell gas, skip the checklist. Turn off the gas supply and call your utility company immediately.
Questions to Ask During the Plumber’s Visit
1. Can you confirm what’s causing the water not to heat?
You’d think this would be obvious, but I’ve heard from homeowners who got charged for a new thermostat when the real problem was a tripped breaker. A good plumber runs specific tests (checking voltage, continuity, gas pressure) before they quote anything. Vague answers like “could be a few things” before they’ve even touched the unit? That’s a red flag.
What a solid answer sounds like: “Your lower heating element is burned out. The upper thermostat tested fine. I can replace just the bad part.”
2. Is this problem repairable, or is the unit near the end of its life?
Tank-style water heaters last about 8-12 years. If yours is 10 years old and needs a $400 repair, you deserve to know that the whole tank could fail next year anyway. A trustworthy plumber will present both options (repair now vs. replace now) with honest numbers for each.
Watch for: plumbers who push replacement on a 4-year-old unit without running diagnostics first. That’s an upsell, not a diagnosis.
3. What type of maintenance could have prevented this?
This question does two things: it tells you how to avoid the same problem in the future, and it tells you whether your plumber actually cares about educating you or just wants to collect a check and leave.
Most electric and gas water heaters need an annual tank flush and an anode rod inspection every 2-3 years. If your plumber shrugs at this question or gives you a generic “just keep an eye on it,” they’re not invested in your long-term outcome.
4. Are there any safety risks with this issue?
Don’t skip this one. Water heaters involve electricity, gas, and pressurized tanks, all things that can hurt people when they malfunction. Your plumber should proactively check the temperature and pressure (T&P) relief valve and inspect for gas leaks. If you’ve noticed a rotten egg smell or hissing sound, mention it immediately. A good plumber takes safety concerns seriously without being dismissive.
5. How long will the repair take and when can hot water be restored?
Mostly a logistics question, but it matters when you’ve got kids who need baths or you’re running a household. A heating element swap usually takes under two hours if the part’s in stock. A full replacement is more like half a day. If parts need ordering, you might be looking at tomorrow or the next day. Get a straight answer so you can plan.
6. Are parts under warranty?
Here’s where you can save real money. Many water heaters come with 6-year or 12-year warranties on the tank and key components. If your unit is still covered, you could pay only for labor. But some plumbers won’t bother checking. They’ll just charge you full price for parts that are under manufacturer warranty.
Tip: Have your model number and purchase date handy. It makes the warranty lookup instant.
Diagnosing the Specific Problem
7. Is the thermostat or heating element bad?
These two components cause the vast majority of “no hot water” calls on electric water heaters. They’re also cheap to replace, usually $20-$50 for the part. The key is making sure your plumber tests each one individually. I’ve seen cases where both the upper and lower elements get swapped out when only one was actually bad. That’s an extra $150 you didn’t need to spend.
8. For gas units, is the pilot light or thermocouple the problem?
Gas water heaters have their own set of usual suspects. A faulty thermocouple (the little sensor that detects whether the pilot light is lit) costs about $20 and takes 30 minutes to replace. Compare that to a full gas control valve replacement at $200-$400. Make sure your plumber checks the smaller, cheaper components before jumping to the expensive ones.
9. Is sediment buildup affecting heating efficiency?
If your water heater sounds like it’s making popcorn, that’s sediment. Mineral deposits settle at the bottom of the tank over time, insulating the water from the heating element and forcing the unit to work harder. In hard-water areas, this can cut your water heater’s lifespan in half.
A tank flush can sometimes solve the problem entirely. Cost: usually $100-$200. Your plumber should also mention a water softener if you’re in a hard-water area. That’s preventive, not an upsell.
10. Could this be an electrical breaker or wiring issue?
Sometimes the water heater itself is fine. The problem’s in the panel or the wiring between the panel and the unit. A good plumber checks the power supply before they start diagnosing internal components. If they jump straight to “you need a new element” without checking whether the element is actually getting power, they’re working backwards.
11. Is the dip tube intact?
This one flies under the radar. The dip tube directs cold incoming water to the bottom of the tank so it gets heated before rising to the top. When it cracks or breaks, cold water mixes with hot water at the top, and your showers go from hot to lukewarm overnight. Replacement cost? Under $50 for the part, usually under $200 total with labor. Quick fix, big difference.
12. Should I install a mixing valve or expansion tank?
Not every home needs these, so don’t let a plumber scare you into buying them. But they’re worth discussing. A mixing valve prevents scalding by blending hot and cold water at the outlet. An expansion tank absorbs pressure spikes that happen when water heats up in a closed system (common in homes with a backflow preventer). If your plumber recommends one, ask them to explain specifically why your setup needs it.
13. Is my tank the right size for my household?
A 30-gallon tank trying to serve a family of four is going to run out of hot water constantly. That’s not a repair problem. It’s a capacity problem. If you’re regularly running out of hot water even when the heater is working, your tank might just be too small. Rule of thumb: 40 gallons for 2-3 people, 50 gallons for 3-4, and 60+ gallons for larger households.
14. Are tankless water heaters a good alternative?
Tankless units heat water on demand, so you never run out. They last about 20 years (nearly double a tank unit), and they cut energy costs because they’re not keeping 40-50 gallons of water hot around the clock. The catch? Upfront costs are significantly higher at $2,500 to $4,500 installed, compared to $1,200 to $2,800 for a tank model. You may also need a larger gas line or upgraded electrical panel. Worth exploring if you’re already facing a full replacement, but don’t let anyone pressure you into it.
15. Do I need a permit or inspection for replacement?
Yes, in almost every municipality. Replacing a water heater typically requires a permit and a follow-up inspection to ensure code compliance. Your plumber should handle the paperwork. If they suggest skipping the permit to save time or money, find a different plumber. Unpermitted work can void your homeowner’s insurance and create problems when you sell.
16. What’s your labor warranty?
A repair that fails two months later shouldn’t cost you twice. Ask about the labor warranty before the plumber starts turning wrenches. 90 days is the minimum I’d accept. Many solid companies offer one year on labor, plus whatever the manufacturer covers on parts. Get it in writing. “We stand behind our work” is a nice sentence, not a warranty.
What to Tell Your Plumber Before They Arrive
Send this info ahead of time if you can. It saves everyone time:
- Photos of the water heater label and the area around it
- Any prior service records or warranty paperwork you have
- When the problem started and whether it’s constant or intermittent
- Whether your unit is gas, electric, or hybrid
- How accessible the unit is (basement, closet, crawl space, attic)
How Much Does Water Heater Repair and Replacement Cost?
Repair: $150 - $600 for most common fixes (heating element, thermostat, gas control, thermocouple).
Tank replacement: $1,200 - $2,800 installed, depending on size and fuel type.
Tankless installation: $2,500 - $4,500, sometimes more if gas line or electrical upgrades are needed.
What drives the price up or down:
- Gas vs. electric vs. hybrid (gas units usually cost more to install)
- Tank size and brand
- Local labor rates and permit costs
- How easy it is to reach the unit (tight crawl spaces add labor time)
- Whether disposal and haul-away of the old unit are included
Red Flags vs. Green Flags
| Red Flag | Green Flag |
|---|---|
| Pushes full replacement before running any tests | Tests individual components first, then presents options |
| Verbal-only estimate, no written quote | Provides a detailed, itemized written quote |
| Skips safety checks (gas, pressure, electrical) | Performs safety inspection before starting repairs |
| Pressures you into upgrades you didn’t ask about | Explains optional improvements and lets you decide |
Money-Saving Tips for Water Heater Owners
- Flush your tank once a year. Sediment is the silent killer of water heaters. A $100-$200 flush can add years to your unit’s life.
- Install a water softener if you have hard water. Hard water accelerates sediment buildup and corrodes the tank faster.
- Turn your thermostat down to 120 degrees F. Most units ship at 140, which wastes energy and increases scalding risk.
- Insulate your tank and hot water pipes. A $25 water heater insulation blanket can cut standby heat loss by 25-45%.
- Ask about manufacturer rebates. Many utility companies and manufacturers offer rebates on high-efficiency models. Your plumber should know about these.
Helpful Tools and Resources
Wrapping your tank with an insulation blanket reduces standby heat loss by 25% to 45%. A $25 investment that typically pays for itself within a few months on your energy bill.
The anode rod is the most important maintenance item on your water heater. Replacing it every 3 to 5 years ($20 to $50 for the part) can add years to your tank's lifespan by preventing internal corrosion.
A clip-on pipe thermometer lets you verify the actual water temperature at the outlet, confirming your thermostat is accurate without waiting for it to reach full temp at a faucet.
- EPA WaterSense Program: Find water-efficient fixtures, including high-efficiency water heaters, and learn about the WaterSense label. Useful when comparing replacement models.
- Energy Star Water Heater Guide: Compare energy-efficient water heaters by type (tank, tankless, heat pump), estimate annual operating costs, and find rebates available in your area.
- Consumer Product Safety Commission (CPSC) Recalls: Search for recalls on your water heater brand and model. Worth checking before you pay for repairs on a unit that might be eligible for a free replacement.
Frequently Asked Questions
How long does a typical water heater last?
Tank-style heaters generally last 8-12 years. Tankless models can hit 20 years or more with regular maintenance. If yours is over 10 years old and acting up, it’s time to start shopping, even if the current repair is minor.
Why does my water heater trip the breaker?
Usually a shorted heating element or faulty wiring. Turn off the power and call a professional. Don’t keep resetting the breaker. A short can cause a fire if the wiring overheats.
What causes water to be warm but not hot?
Nine times out of ten, it’s a failed upper heating element or a thermostat that’s drifted out of calibration. Could also be a broken dip tube mixing cold and hot water. All fixable, usually for under $300.
Is it dangerous if my water heater makes popping noises?
Not immediately dangerous, but don’t ignore it. That popping is sediment hardening at the bottom of the tank. Over time, it reduces efficiency, overworks the burner or element, and shortens the tank’s life. A flush usually solves it.
How often should I flush the water heater?
Once a year minimum. Twice a year if you have hard water. This is the single best thing you can do to extend your water heater’s life, and most people never do it.
Should I replace both elements if one fails?
Only if both test bad. There’s no reason to replace a working element “just in case.” Have your plumber test both with a multimeter. If one reads fine, leave it alone.
Glossary
Thermocouple: A small sensor in gas water heaters that detects whether the pilot light is burning. If it doesn’t sense a flame, it shuts off gas flow as a safety measure. Replacement cost: about $20.
Anode Rod: A sacrificial metal rod inside the tank that attracts corrosive minerals so they eat the rod instead of the tank walls. When the rod is used up, the tank starts corroding. Check it every 2-3 years and replace when it’s more than 50% depleted. Cost: $20-$50 for the part. You can find replacement anode rods for most major water heater brands online.