What a Water Heater Actually Costs
We will not give you a single number, and this page explains why that is the honest answer.
There is no single answer, and anyone giving you one has not looked at your house. Published install cost ranges for overlapping scopes of work differ by thousands of dollars. What we can tell you is the six things that drive your number and what to ask for in a quote so you can compare two of them honestly.
During our research for this site we found published cost ranges for water heater installation that varied from roughly $750 to $2,100 at one end to $1,800 to $5,000 at the other — for scopes of work that overlapped substantially. Those sources were not wrong. They were describing different jobs, in different markets, with different inclusions.
The temptation is to average them and print a confident figure. We will not, because that figure would be a number nobody published, and you might budget against it.
The six things that drive your number
- Is it a swap or a conversion? Same fuel, same location, same capacity is a half-day job. Changing fuel type, capacity or technology means new infrastructure, and the infrastructure is where the money goes.
- Gas line capacity, if you are going tankless. Your old tank burned 40,000 BTU/h; a whole-house tankless unit wants up to 199,900. Upsizing the line is frequently the single largest line item in a tankless conversion, and sometimes the meter has to change too.
- Venting. Reusing an existing flue costs nothing. A new condensing vent run in PVC is moderate. Stainless category III for a non-condensing unit is several times the cost per foot. On a long run this item can exceed the price gap between two heaters.
- Electrical work. A resistance tank reuses its 240 V 30 A circuit. A whole-house electric tankless unit needs 100 A or more of draw across multiple circuits, and if your panel is 100 A or 125 A that is a service upgrade — which usually costs more than the entire water heater.
- Access. A basement with a door to the driveway is cheap. A third-floor laundry closet up two flights with a tight turn is not. A full 50-gallon tank weighs over 500 pounds and does not flex.
- Code-required extras. On a closed system, thermal expansion control is required by IPC 607.3. A drain pan is commonly required where a leak would cause damage. Seismic straps are required in seismic zones. None of these is expensive; all of them belong in the quote.
What drives running cost
Here we can be much more useful, because the ratios transfer even when the rates do not.
| Appliance | Efficiency | Relative energy use |
|---|---|---|
| Electric resistance tank | 0.92 to 0.93 UEF | 1.0x (the baseline) |
| Gas tank | About 0.6 to 0.7 UEF | Lower cost per gallon in most markets, despite the lower UEF, because gas costs less per BTU |
| Gas tankless, condensing | 0.93 to 0.98 UEF | Lower still, plus no standby loss |
| Electric tankless | About 0.99 | Roughly the same energy as a resistance tank, minus standby loss |
| Heat pump water heater | 3.42 to 4.02 UEF | About 0.24 to 0.29x |
What to ask for in a quote
Two quotes are only comparable if they cover the same work. Ask for these six items itemized, and a quote that will not itemize them is telling you something:
- The exact model number. Not "a 50-gallon gas heater". Everything else follows from the model, including the first-hour rating you are actually buying.
- Whether an expansion tank is included, and whether your system is closed. If there is a pressure-reducing valve at the main, it is. Code requirements.
- Whether a drain pan is included and at what diameter. A 50-gallon tank needs a 22-inch pan, not the 20-inch one that fit the old 40. Drain pan sizing.
- What happens to the old unit. Haul-away and disposal is sometimes a separate line.
- Permit and inspection, where required.
- For tankless: gas line sizing, venting, condensate and isolation valves, each separately. These four items are the conversion cost, and a quote that lumps them is impossible to compare.
Where to spend and where not to
| Item | Worth it? | Why |
|---|---|---|
| A bigger first-hour rating | Yes | Undersizing is the complaint people live with for 12 years. Oversizing costs a little standby loss |
| Leak detection with automatic shutoff | Yes, above a finished floor | A leak limited to about 20 ounces is a different outcome from a ceiling repair |
| A heat pump over a resistance tank | Yes, with a suitable space | Roughly a quarter of the running cost and a better first-hour rating |
| A longer warranty | Sometimes | Read what it covers. A 12-year tank warranty with 1 year of labor is not 12 years of free repairs |
| Wi-Fi and app control | Mostly no | Useful on a heat pump for forcing high-demand mode. Otherwise a feature in search of a problem |
| A tankless conversion for its own sake | Usually no | Unless the gas line is already adequate or you are already building |
| An expansion tank | Yes, and it is required | It protects every fixture in the house, not just the heater |
The cheapest thing you can do
Replace the anode rod before it runs out. It costs very little, it takes about an hour, and it is the difference between a tank that reaches 15 years and one that leaks at 8. Nobody does it, which is why identical tanks in identical houses fail years apart. Anode rods.
What goes in with it
A water heater is a system, not a box. These are the parts that go in with it, and the ones people discover they need halfway through the job.
- Expansion tank
Required by code on a closed system, which is most homes with a pressure-reducing valve.
- Drain pan
Cheap insurance anywhere the tank sits above something you care about.
- Anode rod
The part that decides when the tank leaks. Replacing it is the highest-value hour of maintenance there is.