How much does it cost to replace a water heater?
A like-for-like tank swap lands near $1,500 to $2,000. Changing technology — tankless, heat pump — is a different project with a different budget.
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The numbers at a glance
- Gas tank, 40 – 50 gal
- $1,500 – $2,800
- Electric tank
- $900 – $1,800
- Tankless, gas
- $2,500 – $5,500
- Heat pump water heater
- $3,000 – $6,000
- Typical service life, tank
- 8 – 12 years
What a water heater replacement costs
Replacing a tank with another tank of the same size and fuel is the cheapest and most common job: one day, one unit, the existing vent and connections reused. The price range comes from fuel type, capacity and what the code requires around the unit.
Changing technology is where the numbers jump. A tankless unit needs a larger gas line, a different vent and, for some homes, an electrical upgrade. A heat pump water heater needs space, condensate drainage and usually a 240-volt circuit.
If the old unit is failing, price the replacement before it fails completely. An emergency call-out on a weekend costs more than the same job scheduled.
Installed cost by type, 2026 national averages
| System | Installed cost | What it includes |
|---|---|---|
| Electric tank, 40 – 50 gal | $900 – $1,800 | Unit, labour, expansion tank, pan, permit |
| Gas tank, 40 – 50 gal | $1,500 – $2,800 | Same, plus vent connector and gas fittings |
| Tankless, gas | $2,500 – $5,500 | Unit, venting upgrade, larger gas line, labour |
| Tankless, electric | $1,500 – $3,500 | Unit, dedicated circuits, labour |
| Heat pump | $3,000 – $6,000 | Unit, condensate line, circuit, labour; rebates often apply |
Prices assume the unit sits where the old one did. Relocating a water heater is a plumbing and venting project, not a replacement.
Where the money goes
On a like-for-like replacement the unit is roughly half the invoice. The rest is labour, the safety parts around the unit, and the permit.
The safety parts are the ones homeowners rarely ask about and inspectors always look for: a drain pan with a pipe to a drain, a temperature and pressure relief valve piped to within six inches of the floor, and a thermal expansion tank on a closed system.
Share of a typical tank replacement
| Component | Share | What it covers |
|---|---|---|
| Water heater unit | 40 – 55% | Tank, burner or elements, insulation, controls |
| Installation labour | 25 – 35% | Drain, disconnect, remove, set, connect, test |
| Safety components | 5 – 12% | Pan and drain line, expansion tank, new flex connectors |
| Permit and inspection | 3 – 8% | Local plumbing permit, inspection of venting and relief |
| Disposal | 2 – 5% | Old unit removed and recycled |
A quote without a pan, an expansion tank and a permit is not cheaper — it is incomplete, and an inspector can require it redone.
- Capacity: match the first-hour rating to the household, not just the tank size in gallons.
- Fuel: gas is cheaper to run, electric is cheaper to install where no gas line exists.
- Venting: a gas unit needs a compliant flue or a sealed power vent; this is often the hidden cost.
- Location: a garage, basement or closet install changes the pan, drain and vent requirements.
- Efficiency: higher-efficiency models cost more up front and less per month — check local rebates first.
A worked example: 50-gallon gas tank, garage, same footprint
The most common job we see: a 50-gallon gas tank in a garage, replaced in place, with the existing vent reused. No gas line work, no relocation, no electrical change.
50-gallon gas tank, replaced in place
Priced at national averages, including the safety parts a compliant install requires.
- Water heater unit50 gal, 40,000 BTU, 6-year tank warranty
- $780
- Installation labourDrain, remove, set, connect, test
- $520
- PermitPlumbing permit and inspection
- $120
- Thermal expansion tankRequired on a closed system with a check valve
- $180
- Drain pan and discharge linePan with a line to the exterior
- $160
- Flex connectors and shut-offNew gas connector, water flex lines, ball valve
- $140
- DisposalOld unit removed and recycled
- $80
$1,980 — one day, one visit
Add a 10% allowance ($198) for a corroded shut-off valve or a vent connector that fails inspection, and budget about $2,180. A tankless conversion at the same address would start around $3,500 once venting and the gas line are upgraded.
Repair or replace?
The usual rule of thumb: if the repair costs more than half of a new installed unit, replace it. That threshold arrives quickly on a tank older than eight years.
Age is not the only signal. Water on the floor, rust at the tank seams, a rumbling sound from sediment, or a relief valve that keeps discharging are all end-of-life signs, not maintenance items.
Repair or replace, by situation
| Situation | Age | What to do |
|---|---|---|
| Leak from the tank body | Any | Replace — a rusted tank cannot be repaired |
| Leak from a fitting or valve | Under 8 years | Repair, if the tank is sound |
| No hot water, tripped breaker | Any | Diagnose first; elements and thermostats are cheap to replace |
| Sediment rumbling, slow recovery | Over 8 years | Replace — flushing rarely restores it |
| Relief valve discharging | Any | Investigate immediately; could be pressure or a failed valve |
A tank leak under pressure can cause several thousand dollars of water damage in an hour. Replace rather than wait.
Tankless: when it pays, when it does not
Tankless units heat water on demand and last roughly twice as long as a tank, but the installation is where the money goes. Most homes need a larger gas line, a new stainless vent and sometimes a bigger meter.
The savings claim is real but modest for a typical household — often 10% to 20% of water-heating energy, not the 30% the sales material implies, because a tank does not lose as much as older figures suggest once it is insulated.
Tankless makes sense when the install is straightforward: gas available, short vent run, and a household that wants endless hot water or has limited floor space.
- Check the gas meter capacity before committing — upsizing the line or the meter is a big line item.
- Flow rate matters: size by gallons per minute for simultaneous showers, not by the number of bathrooms.
- Vent runs are short and expensive; a condensing unit needs an outside wall or a sealed vent.
- Maintenance is annual descaling in hard-water areas — budget for it.
- Heat pump water heaters are often the better choice than tankless where the unit lives in a garage or basement.
How long a water heater replacement takes
A like-for-like swap is a half-day job. Anything that changes fuel, venting or location is not.
Diagnosis and quote
1 – 2 days
Confirm the failure, measure the space, check venting and gas capacity.
Permit
1 – 5 days
Many jurisdictions issue over the counter; some require a day or two.
Drain and removal
1 – 2 hours
Shut the water and gas off, drain, disconnect, haul the old unit out.
Installation and connections
2 – 4 hours
Set the new unit, connect water, gas or electrical, vent and relief line.
Fill, test, inspect
1 – 2 hours
Purge air, check for leaks, confirm the relief valve and venting.
Total: one day for a tank replacement. Tankless conversions run two to three days once gas and venting are upgraded.
The six most expensive water heater mistakes
These are the ones that show up as water damage, failed inspections or a second invoice.
Skipping the drain pan and its line
A tank fails from the bottom up. Without a pan and a drain line, the first sign of failure is a flooded garage or ruined flooring.
Piping the relief valve into a wall or capping it
The temperature and pressure relief valve must discharge to within six inches of the floor, visibly. Anything else is a serious safety defect.
Reusing a corroded vent connector
Flue gas is the risk. A rusted or wrongly sloped connector can spill carbon monoxide into the room; replace it with the unit.
No expansion tank on a closed system
A backflow preventer turns the plumbing into a closed loop. Without an expansion tank, pressure spikes and the relief valve discharges or a fitting fails.
Sizing by tank gallons instead of first-hour rating
A family of four with two showers running needs recovery capacity, not just a bigger tank. Size on the first-hour rating.
Never replacing the anode rod
The anode is what protects the steel tank. In hard water it is consumed in a few years; replacing it is inexpensive and can double the life of the unit.
Before you approve a water heater quote
A compliant installation has line items for each of these. Ask where they are.
- Confirm the fuel type, capacity and first-hour rating of the quoted unit.
- Check that a permit and inspection are included.
- Confirm the drain pan and where its discharge line goes.
- Confirm the relief valve is piped to within six inches of the floor.
- Ask whether a thermal expansion tank is required and included.
- Confirm the vent connector or flue is new, correctly sloped and included.
- Ask for the warranty terms in writing: tank, parts and labour are separate.
- Confirm disposal of the old unit and the emergency call-out rate.
Put a number on your project
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Frequently asked questions
How much does it cost to replace a water heater?
A tank replacement runs about $900 to $2,800 installed depending on fuel type and capacity, with most homeowners near $1,500 to $2,000 for a like-for-like swap. Tankless systems cost $2,500 to $5,500 once the vent and gas line are upgraded.
How long does a water heater last?
A tank water heater lasts 8 to 12 years in typical conditions, shorter in hard water. Tankless units last about 20 years, and heat pump water heaters 15 years. Replacing the anode rod every few years is the cheapest way to extend a tank.
Is tankless worth the extra cost?
It depends on the installation. Where gas is available, the vent run is short and the household wants unlimited hot water or needs the floor space, yes. If the gas line and meter need upsizing, the payback rarely works on energy savings alone.
Do I need a permit to replace a water heater?
In most US jurisdictions, yes — a plumbing permit and an inspection are required for a water heater replacement, mainly to verify venting and the relief valve. The fee is modest and the inspection protects you if the unit is later involved in a claim.
Can I replace a water heater myself?
In many places a homeowner may do it on their own property, but the permit, the venting rules and the relief valve requirements still apply, and a mistake can be dangerous. Gas connections and venting are the two areas where a professional is worth the cost.
Why is my new water heater making noise?
Rumbling or popping is usually sediment or trapped air. On a new unit it often settles within a few days after the lines are purged. If it persists, check the water pressure and whether the tank was properly flushed before installation.
Where these numbers come from
Ranges are national averages for 2026, installed, for a replacement in the existing location. Code requirements vary by state and municipality.
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