Best Water Heater Drain Pans
Cheap, boring, and the difference between a wet floor and a ceiling repair.
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Match the pan to the tank diameter plus clearance for the drain fitting: 20 inches for a 30 to 40 gallon tank, 22 inches for a 50, 26 inches for an 80 gallon or a heat pump unit. Aluminum survives a tank being dragged across it; plastic does not corrode in standing condensate. Both need a real drain to be worth anything.
A drain pan is the least interesting item on this site and one of the highest-value. It costs very little, it takes two minutes to fit during a replacement, and it converts the eventual tank failure from a flooring and drywall claim into a puddle in a pan.
The two ways people get it wrong: buying the wrong diameter, and fitting a pan with nowhere for the water to go.
Quick picks
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| # | Product | Best for | Price |
|---|---|---|---|
| 1 | Camco 20841 aluminum pan, 22 inThe 22-inch aluminum pan: the right size under a standard 50-gallon tank, which is itself usually 22 inches in diameter. | 50 gallon tanks | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 2 | Camco 20800 aluminum pan, 20 inA 20-inch inside-diameter aluminum pan with a PVC fitting — the correct size under most 30- and 40-gallon tanks, which measure around 18 inches across. | 30 and 40 gallon tanks | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 3 | Camco 11400 plastic pan, 26 inTwenty-six inches across and 2-1/2 inches deep in plastic — the size that actually fits under an 80-gallon tank or a wide heat pump unit. | 80 gallon and heat pump tanks | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 4 |  Camco 11430 Wall Saver tankless panA rectangular pan sized for a wall-hung tankless heater rather than a cylinder, in aluminum with a bottom drain connection. | Wall-hung tankless units | Check price on Amazon No live price feed on this site, so we show none. #ad |
The picks in full
Pick 1 — 50 gallon tanks
Camco 20841 aluminum pan, 22 in
The 22-inch aluminum pan: the right size under a standard 50-gallon tank, which is itself usually 22 inches in diameter.
| Inside diameter | 22 in |
|---|---|
| Depth | 2.25 in |
| Material | Aluminum |
| Drain fitting | PVC |
What is good
- Matches the 22-inch diameter of the common 50-gallon tank with room for the fitting
- Aluminum construction
- Standard PVC drain connection
- Fits the alcove a 50-gallon tank already occupies
What is not
- A 22 in pan under a 22 in tank is a tight fit — check the drain boss clears
- 2.25 in depth
- Requires a gravity drain path
Skip it if: Skip it for a heat pump water heater. Those are usually wider than a resistance tank of the same capacity and also produce condensate continuously, which means a larger pan and a committed drain, not a shallow pan.
No live price feed on this site, so we show none. #ad
Specifications above from Pacific Plumbing listing, Camco 20841; HD Supply listing, Camco 22 in ID pan. We have not tested this unit ourselves.
Pick 2 — 30 and 40 gallon tanks
Camco 20800 aluminum pan, 20 in
A 20-inch inside-diameter aluminum pan with a PVC fitting — the correct size under most 30- and 40-gallon tanks, which measure around 18 inches across.
| Inside diameter | 20 in |
|---|---|
| Depth | 2-1/4 in |
| Material | Aluminum |
| Drain fitting | PVC, included |
What is good
- Aluminum does not crack when a tank is dragged across it the way thin plastic does
- 20 in ID clears the typical 18 in diameter of a 40-gallon tank
- Pre-fitted PVC drain connection
- Cheap enough that there is no argument for skipping it
What is not
- 2-1/4 in deep holds a leak, not a tank failure
- Aluminum corrodes where it sits in standing water with dissimilar metals
- Needs a real drain or the pan just delays the damage
Skip it if: Skip it if your heater is a 50-gallon or larger tank. Those measure 18 to 22 inches across and the clearance the pan needs for the drain fitting means a 20-inch pan will not take it.
No live price feed on this site, so we show none. #ad
Specifications above from Auer Steel listing, Camco 20800; HD Supply listing, Camco 20 in ID aluminum pan. We have not tested this unit ourselves.
Pick 3 — 80 gallon and heat pump tanks
Camco 11400 plastic pan, 26 in
Twenty-six inches across and 2-1/2 inches deep in plastic — the size that actually fits under an 80-gallon tank or a wide heat pump unit.
| Inside diameter | 26 in |
|---|---|
| Depth | 2-1/2 in |
| Material | Plastic |
| Drain fitting | PVC |
What is good
- 26 in clears the larger diameter of 80-gallon and heat pump tanks
- Deepest pan in this registry at 2-1/2 inches
- Plastic will not corrode in standing condensate the way aluminum can
- Takes the same PVC drain connection as the metal pans
What is not
- Plastic can crack in cold weather or under the weight of a dragged tank
- 26 inches may not fit the alcove the old tank came out of
- Still only a pan, not a shutoff
Skip it if: Skip plastic if the installer is going to walk a full tank across the pan. On a replacement day a thin plastic pan takes the weight of a 500 lb full tank being rocked into position — put aluminum under that.
No live price feed on this site, so we show none. #ad
Specifications above from Do It Best listing, Camco 26 in plastic pan. We have not tested this unit ourselves.
Pick 4 — Wall-hung tankless units
Camco 11430 Wall Saver tankless pan
A rectangular pan sized for a wall-hung tankless heater rather than a cylinder, in aluminum with a bottom drain connection.
| Shape | Rectangular |
|---|---|
| Nominal size | 11-5/8 in |
| Material | Aluminum |
| Drain connection | Bottom |
What is good
- Shaped for a wall-hung unit, which round pans are not
- Bottom connection suits a drop straight into a floor drain
- Aluminum rather than plastic
- Catches the condensate drip a condensing unit produces as well as a leak
What is not
- Only useful under a wall-hung unit
- Small catchment: a burst connection will overrun it
- Needs mounting as carefully as the heater itself
Skip it if: Skip it if your tankless unit hangs over an unfinished basement floor with a drain. There is nothing underneath to protect, and the condensate line should go to the drain directly rather than via a pan.
No live price feed on this site, so we show none. #ad
Specifications above from Pace Supply listing, Camco 11430 Wall Saver. We have not tested this unit ourselves.
Sizing: tank diameter plus clearance
| Tank | Typical diameter | Pan size | Example |
|---|---|---|---|
| 30 to 40 gal | 18 to 20 in | 20 in | Camco 20800, aluminum |
| 50 gal | 22 in | 22 in | Camco 20841, aluminum |
| 50 gal with clearance to spare | 22 in | 24 in | Camco 24 in aluminum |
| 75 to 80 gal | 24 to 26 in | 26 in | Camco 11400, plastic |
| Heat pump unit | Often wider than a resistance tank | 26 in, and check the model | Camco 11400 |
| Wall-hung tankless | Rectangular footprint | Tankless pan | Camco 11430 Wall Saver |
Aluminum or plastic
| Aluminum | Plastic | |
|---|---|---|
| Survives a tank dragged across it | Yes | Can crack |
| Cold weather brittleness | No | Yes, in an unheated space |
| Corrosion in standing water | Can corrode with dissimilar metals | No |
| Available depth | 2-1/4 in typical | 2-1/2 in on the 26 in Camco |
| Best for | Replacement day, where the tank gets moved on it | Heat pump units with continuous condensate |
The practical rule: aluminum where the tank will be walked into position on the pan, plastic where the pan will sit in standing condensate for years. A heat pump water heater is the second case, and it is also where the pan matters most.
A pan without a drain is a delay, not a fix
Every pan here comes with a PVC drain fitting, and that fitting needs to go somewhere: a floor drain, a laundry standpipe, or outside where code permits. A pan with a capped fitting holds a couple of gallons and then overflows.
Which is the honest limit of this product. A 2-1/4 inch deep pan handles a weeping seam or a dripping relief valve. It does not handle a tank letting go. For that you need either a drain that can carry the flow or an automatic shutoff valve.
The tankless case
A wall-hung tankless unit needs a rectangular pan, not a round one. The Camco 11430 Wall Saver is aluminum with a bottom drain connection, sized for the footprint of a wall-mounted heater.
It is worth fitting in two situations: where the unit hangs above a finished space, and where a condensing unit's condensate line could block and overflow. Over an unfinished basement floor with a drain, there is nothing underneath to protect and the condensate should go straight to the drain instead.
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.
- Drain pan
A heat pump water heater makes condensate continuously, so this one is not optional.
- Leak detector
A condensate line that blocks will overflow long before you notice it.
- Expansion tank
Same closed-system rule as any other storage tank.
How we chose
Published inside diameter and depth, then material against the install, then whether the drain fitting is included. We have not tested these pans. How we pick.