LEARNING CENTER WATER HEATERS
How Long Does a Water Heater Replacement Actually Take?
The short answer
A standard 40 or 50 gallon tank swap is about half a day on site. Our pricebook bills 2.57 to 3.00 hours of labor, and the job is almost always finished in one visit, usually a few hours from arrival to cleanup. Going tankless is the exception, at most of a full workday.
Most people don’t get a straight answer on this up front, so here it is. A regular tank water heater, the 40 or 50 gallon gas or electric unit sitting in most Louisville basements, comes out and goes back in before lunch. Our pricebook puts the wrench time at 2.57 hours for a 50 gallon gas swap and 3.00 hours for a 40 gallon. Add hauling the old tank out, pulling the permit, and cleaning up, and you’re looking at roughly half a day with a truck in the driveway.
The number that surprises people isn’t the tank. It’s the tankless. A high-efficiency tankless conversion is a different animal, and it can eat most of the workday. So the real question is which kind you’re putting in, not how long “a water heater” takes.
The short version, by type
- Standard gas or electric tank 2.57 to 3.00 billed hours. A 40 gallon natural gas swap runs about $2,200–$2,400 and a 50 gallon around $2,300–$2,500. Call it a morning on site, one visit, hot water back by early afternoon.
- Power vent or direct vent tank Barely longer on the clock, 2.90 to 3.06 hours, so still basically a morning. The jump is the price, not the time. A 50 gallon power vent lands near $5,200–$5,400 and a 40 gallon direct vent near $5,600–$5,800 because of the sealed venting and extra gas work. Don’t let anyone tell you a vented tank costs you your whole day.
- 75 gallon power vent This one does add real time, about 5.0 hours, most of a workday, because of the size and the venting that goes with it.
- Tankless This is where the clock really jumps. About 4.73 hours for a straightforward indoor gas unit, up to 6.50 hours for a high-efficiency model with built-in recirculation. Plan on most of the day. A mid-efficiency tankless runs about $5,300–$5,500 and a high-efficiency one about $6,400–$6,600.
- You bought it, we install it A customer-supplied install runs about 2.25 hours at $1,000–$1,200, gas or electric.
Why tankless takes most of the day
A like-for-like tank swap reuses what’s already there. The gas line and vent are usually right where they need to be, and the water hookups line up. A tankless conversion is closer to a small remodel than a swap. The gas line often has to be upsized to feed the burner, the venting is a different setup, and you’re adding new mounting and condensate handling. None of it is hard for a plumber who does it regularly. It just takes hours the tank job doesn’t.
What makes a job run longer
- Where the heater lives A tank sitting open in the basement next to the main is quick. One boxed into a finished closet, up a tight stairwell, or wedged behind storage adds time before we touch a fitting. Getting the old tank out is often half the work.
- Attic and crawlspace installs Water heaters in an attic or crawlspace are slower to reach and slower to work in, and code adds requirements like a proper pan and drain that a basement install may already have.
- Code upgrades If the old install predates current code, we bring it up to spec. That might mean a new expansion tank, a proper drip pan and drain line, an updated gas flex connector, or reworking the vent. It’s not padding, it’s what passes inspection.
- The permit and inspection A licensed replacement includes pulling a plumbing permit and a follow-up inspection. The install still happens the day we’re there, but the paperwork is part of doing it right.
When to expect longer than half a day
A straight tank swap is a morning. These situations aren’t, so know before you book:
- You’re switching to tankless New gas sizing, new venting, often a new gas line. Most of a day, sometimes a scheduled follow-up.
- You’re moving the unit Relocating a heater to a new spot means running new water, gas, and vent. That’s a bigger job than swapping in place.
- The old install wasn’t to code Bringing the vent, gas line, or drain up to current code adds hours on top of the swap itself.
- Access is rough Attic, crawlspace, or a cramped finished closet. Wrestling the old tank out is where the clock runs.
The Kentucky permit wrinkle
Here’s something specific to Louisville that catches people off guard. In most states your city or county issues the plumbing permit. Not here. Kentucky routes water heater permits through the state Division of Plumbing, and the fee for a single water heater replacement in one building is a flat $50 under 815 KAR 20:050. A proper install includes pulling that permit and a follow-up inspection. The inspection is scheduled separately, so it never keeps you without hot water, but it’s a real part of a licensed job and worth knowing about up front.
Common questions we get
Will I be without hot water overnight?
Almost never for a standard tank. We pull the old one and set the new one the same visit, and you’ve usually got hot water back by early afternoon. A tankless conversion is the one case that can stretch, and even then it’s typically finished the same day.
Can you replace it the same day I call?
Often, if we’ve got your size and fuel type on the truck. A 40 or 50 gallon gas or electric tank is stock work. A specific tankless model or an odd size might need a day to source first.
Does the permit slow the job down?
No. The install happens the day we’re on site. The permit and the inspection are handled around it, and the inspection gets scheduled separately. It doesn’t leave you without hot water.
Why did my neighbor’s take so much longer?
Usually they went tankless, or their old setup needed code work brought up to spec before it’d pass. Bad access can add time too. Same-size, like-for-like tank swaps are the fast ones.
The next questions to ask
Not sure which kind of install your home needs, or how long it’ll take?
Ask Goldie for a real timeline and price at goldenplumbingky.com/instant-estimate/