Best 50 Gallon Water Heaters
The default American size. Same badge number, first-hour ratings from 63 to 91 gallons.
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At 50 gallons the fuel decides everything. The A. O. Smith Signature 100 gas unit delivers 91 gallons in the first hour; the Rheem ProTerra heat pump delivers 67 gallons at a 3.88 UEF; a resistance tank delivers 63 gallons. Same volume, three different appliances.
Fifty gallons is the most installed water heater size in the United States, which makes this the most consequential page on the site for the largest number of people. The good news is that the default is a good default. The useful news is that the spread between the best and worst 50-gallon tank, measured in hot water delivered, is 28 gallons an hour.
Quick picks
Tap any row to read the full assessment below, or go straight to Amazon from the right-hand column. We earn a commission on qualifying purchases at no extra cost to you.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 |  A. O. Smith Signature 100, 50 gal gasThe straightforward 50-gallon gas replacement, and the reason to pay attention to the burner size: the 50,000 BTU version is rated at a 91-gallon first-hour rating against 77 gallons for the 40,000 BTU one. | Most gas tank replacements | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 2 |  Rheem ProTerra 50 gal hybridThe heat pump water heater to start with: a 3.88 UEF, a 67-gallon first-hour rating, and a 37°F lower operating limit that is the widest ambient range in its class — which is the specification that decides whether it works in a cold garage. | Most heat pump installs | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 3 |  Rheem Gladiator 50 gal electricThe electric tank to put above a finished floor: integrated leak detection with an automatic shutoff valve that limits a leak to around 20 ounces, plus a 12-year tank and parts warranty. | Electric tanks in finished spaces | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 4 |  Bradford White RG2PDV50S6NThe direct-vent tank to specify when combustion air is the problem: 83-gallon first-hour rating from 40,000 BTU/h, and it draws its air from outside instead of from the room. | Sealed closets and tight mechanical rooms | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 5 | Rheem Performance Platinum 50 gal electricA plain, well-warranted 50-gallon electric tank: a 63 gallon-per-hour first-hour rating, 21 gallons per hour of recovery at a 90°F rise, and a 0.93 UEF. | Straight electric replacement | Check price on Amazon No live price feed on this site, so we show none. #ad |
The picks in full
Pick 1 — Most gas tank replacements
A. O. Smith Signature 100, 50 gal gas
The straightforward 50-gallon gas replacement, and the reason to pay attention to the burner size: the 50,000 BTU version is rated at a 91-gallon first-hour rating against 77 gallons for the 40,000 BTU one.
| Capacity | 50 gallons |
|---|---|
| First-hour rating | 91 gallons (50,000 BTU model); 77 gallons (40,000 BTU model) |
| Burner | 50,000 BTU/h ultra-low NOx, or 40,000 BTU/h |
| Dimensions | 61 in H x 22 in dia (50,000 BTU); 60-3/4 in H x 22 in dia (40,000 BTU) |
| Warranty | 6-year tank and parts with 1-year labor (50,000 BTU); 9-year tank and parts with 2-year labor (40,000 BTU) |
What is good
- A 91-gallon first-hour rating from a 50-gallon tank covers back-to-back showers that empty an electric tank of the same size
- Widely stocked at Lowe's, so same-day replacement is realistic when the old one fails
- Ultra-low NOx burner meets the stricter air-district rules in California and Texas
- 22-inch diameter fits most existing alcoves without re-plumbing
What is not
- The longer 9-year warranty is on the smaller burner, so warranty and recovery pull in opposite directions
- Atmospheric venting needs a working chimney or B-vent
- Standing pilot and flue losses mean it idles energy away all day
Skip it if: Skip it if your water heater sits in a sealed closet or a space with combustion air problems. An atmospheric gas tank needs real combustion air and a real flue — the power-vent or direct-vent models exist for exactly that case.
No live price feed on this site, so we show none. #ad
Specifications above from Lowe's listing, Signature 100 50-gal 50,000 BTU; Lowe's listing, Signature 100 50-gal 40,000 BTU 9-year. We have not tested this unit ourselves.
Pick 2 — Most heat pump installs
Rheem ProTerra 50 gal hybrid
The heat pump water heater to start with: a 3.88 UEF, a 67-gallon first-hour rating, and a 37°F lower operating limit that is the widest ambient range in its class — which is the specification that decides whether it works in a cold garage.
| Capacity | 50 gallons |
|---|---|
| Efficiency | 3.88 UEF; up to 4.07 UEF advertised on 30 A models |
| First-hour rating | 67 gallons |
| Recovery | 27 gallons per hour |
| Heat pump capacity | 4,200 BTU/h |
| Backup element | 5,000 W |
| Voltage | 208 - 240 V |
| Ambient operating range | 37 - 145°F |
| Cold-climate rating | Meets Northern Climate Specification Tier 4 |
| Leak protection | Integrated detection with factory-fitted auto shutoff; leaks limited to no more than 20 oz |
| Warranty | 10-year limited |
What is good
- A 37°F lower limit means the compressor keeps running in an unheated garage through most of a northern winter
- 3.88 UEF is roughly four times a resistance tank, so the running cost difference is not marginal
- 67-gallon first-hour rating is better than most 50-gallon resistance tanks
- EcoNet control lets you force high-demand mode before guests arrive instead of discovering the limit
What is not
- It is a refrigeration appliance in your house: there is a compressor, a fan and a condensate drain
- Needs roughly 700 cubic feet of air, or louvered doors, in a closet
- It cools and dehumidifies the space it stands in, which is a gift in a Houston garage and a problem in a Minnesota basement
Skip it if: Skip it if the only place it can go is a finished, heated room you occupy. It will steal heat from that room in winter — your furnace then pays for the hot water, and the efficiency you bought disappears.
No live price feed on this site, so we show none. #ad
Specifications above from Rheem ProTerra PROPH50 T2 RH375-30 product page; ABR Wholesalers listing, PROPH50 T2 RH375-30. We have not tested this unit ourselves.
Pick 3 — Electric tanks in finished spaces
Rheem Gladiator 50 gal electric
The electric tank to put above a finished floor: integrated leak detection with an automatic shutoff valve that limits a leak to around 20 ounces, plus a 12-year tank and parts warranty.
| Capacity | 50 gallons |
|---|---|
| Elements | 5,500 W double element, 240 V |
| First-hour rating | 63 gallons |
| Efficiency | 0.92 UEF |
| Leak protection | 360° LeakSense detection with factory-fitted automatic shutoff; leaks limited to no more than 20 oz |
| Warranty | 12-year tank and parts, 3-year labor |
What is good
- The auto-shutoff valve is the single most valuable feature on any tank installed over drywall
- 12-year tank and parts with 3-year labor is among the longest electric warranties sold at retail
- 5,500 W double element gives faster recovery than the usual 4,500 W pair
- Leak alerts arrive before the ceiling does
What is not
- A 63-gallon first-hour rating from 50 gallons is ordinary — electric recovery is slow, full stop
- Running cost is electric-rate running cost; a heat pump model costs far less to run
- The shutoff valve is one more serviceable part in the cold inlet
Skip it if: Skip it if the heater lives on a concrete slab next to a floor drain and you have the headroom for a heat pump model. You are paying for leak protection you can get from a 20-dollar pan, and giving up the running-cost saving a heat pump would deliver.
No live price feed on this site, so we show none. #ad
Specifications above from Home Depot listing, Rheem Gladiator XE50T12CS55U1. We have not tested this unit ourselves.
Pick 4 — Sealed closets and tight mechanical rooms
Bradford White RG2PDV50S6N
The direct-vent tank to specify when combustion air is the problem: 83-gallon first-hour rating from 40,000 BTU/h, and it draws its air from outside instead of from the room.
| Capacity | 50 gallons nominal, 48 gallons rated storage |
|---|---|
| First-hour rating | 83 gallons |
| Input | 40,000 BTU/h |
| Efficiency | 0.71 UEF, 78% recovery efficiency |
| Venting | Direct vent — combustion air from outdoors |
| Tank lining | Vitraglas enamel |
| Safety system | Defender FVIR with ScreenLok flame arrestor |
| Warranty | 6-year limited |
What is good
- 83 gallons in the first hour from a 40,000 BTU burner is the best ratio on this page
- Direct venting solves the sealed-closet and tight-house combustion air problem outright
- Hydrojet sediment reduction genuinely helps first-hour delivery on hard water
- Defender FVIR is standard, not an upcharge
What is not
- Sold through plumbing wholesalers rather than big-box retail, so weekend DIY sourcing is harder
- 6-year warranty where some competitors sell 9- and 12-year tanks
- 0.71 UEF is ordinary — this is a reliability and venting pick, not an efficiency one
Skip it if: Skip it if your old heater vents into a shared chimney with a furnace and you were not planning to touch the venting. Direct vent means cutting a new sidewall penetration, and that changes the job from a swap into an install.
No live price feed on this site, so we show none. #ad
Specifications above from PEX Universe listing, RG2PDV50S6N; Supply House listing, Bradford White RG2PV50T6N power vent. We have not tested this unit ourselves.
Pick 5 — Straight electric replacement
Rheem Performance Platinum 50 gal electric
A plain, well-warranted 50-gallon electric tank: a 63 gallon-per-hour first-hour rating, 21 gallons per hour of recovery at a 90°F rise, and a 0.93 UEF.
| Capacity | 50 gallons |
|---|---|
| First-hour rating | 63 gallons per hour |
| Recovery | 21 gallons per hour at a 90°F rise |
| Efficiency | 0.93 UEF |
| Voltage | 240 V |
What is good
- Publishes recovery at a stated temperature rise, which most retail listings do not
- 0.93 UEF is at the top of what a resistance tank can do
- Drop-in replacement dimensions for the previous generation
- Available in short and tall variants
What is not
- 21 gallons per hour of recovery is a third of what a gas tank does
- No leak detection on this model
- Resistance heating is the most expensive way to make hot water in most of the country
Skip it if: Skip it if you have 7 feet of headroom and an unconditioned space to put it in. A heat pump model in that spot uses roughly a third of the electricity for the same hot water, and the payback is measured in a few years, not decades.
No live price feed on this site, so we show none. #ad
Specifications above from Home Depot specification sheet, Rheem Performance Platinum electric (PDF). We have not tested this unit ourselves.
The one table that matters
| Unit | Fuel | First-hour rating | Efficiency | Warranty |
|---|---|---|---|---|
| A. O. Smith Signature 100, 50,000 BTU | Natural gas | 91 gal | Not published as UEF on the listing | 6-year tank and parts |
| Bradford White Defender direct vent | Natural gas | 83 gal | 0.71 UEF, 78% recovery efficiency | 6-year limited |
| A. O. Smith Signature 100, 40,000 BTU | Natural gas | 77 gal | Not published as UEF on the listing | 9-year tank and parts |
| Rheem ProTerra hybrid | Electric heat pump | 67 gal | 3.88 UEF | 10-year limited |
| Rheem Gladiator | Electric resistance | 63 gal | 0.92 UEF | 12-year tank and parts, 3-year labor |
| Rheem Performance Platinum | Electric resistance | 63 gal | 0.93 UEF | Per model listing |
Three things worth noticing. The longest warranty here is on the electric resistance tank, which is also the least efficient. The best delivery is gas. And the heat pump sits in the middle on delivery while using roughly a quarter of the energy of the resistance unit below it.
Which one, by situation
- You have gas and a working flue → the A. O. Smith Signature 100. Pick the 50,000 BTU version for five people, the 40,000 BTU version for four and take the longer warranty.
- You have gas but the heater is in a sealed closet → the Bradford White Defender direct vent. It solves combustion air outright and gets 83 gallons from a 40,000 BTU burner.
- You are electric with a garage, unfinished basement or utility space → the Rheem ProTerra. Better delivery than a resistance tank and a quarter of the running cost.
- You are electric and the tank is above a finished floor → the Rheem Gladiator, for the automatic leak shutoff and the 12-year warranty.
- You are electric, simple swap, lowest cost now → the Rheem Performance Platinum.
Does a 50 gallon tank fit where yours was?
If you are replacing a 50 with a 50, usually yes. If you are coming up from 40, check:
- Diameter. 22 inches is typical at 50 gallons against 18 to 20 at 40. The A. O. Smith Signature 100 50-gallon is listed at 22 inches.
- Height. Around 60 to 61 inches for a tall model, plus clearance above for the flue or the cold inlet and expansion tank.
- Drain pan. A 22-inch tank needs a 22-inch pan with room for the drain fitting. Drain pan sizing.
- Access. It is a two-person carry, and a full tank at this size weighs over 500 pounds.
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.
How we chose
Published first-hour rating first, then efficiency as UEF where published, then warranty terms as the manufacturer or retailer states them, then install fit. We ranked across fuels rather than separately, because at this capacity the fuel is the decision. We have not tested these units. How we pick.