40 gallon short water heater dimensions
| Tank heightvaries by brand — measure the model before buying | 46–50″ |
|---|---|
| Tank diameter | 20–23″ |
| Height the space needstank plus 6″ for the connections and the T&P valve | 56inches |
| Width the space needstank plus 6″ each side to get a hand in | 35inches |
| Clear space in frontto change an element, a thermostat or the T&P valve | 24inches |
| Ceiling height to pull the anodethe rod is about 44″ and it comes straight up | 94inches |
Notes
- The anode clearance is the measurement nobody takes. The rod is roughly 44 inches long and it lifts vertically out of the top of the tank, so replacing it wants about 94 inches of ceiling. In a basement with 7-foot joists on a tall tank, there is not room — and the anode is the single part that decides whether the tank lasts eight years or eighteen. Where the ceiling is low, buy a segmented rod at install time; discovering the problem later means draining the tank twice.
- A replacement tank is usually fatter than the one it replaces. The 2015 efficiency standards added insulation, and on tanks over 55 gallons they changed the technology entirely. A closet built around a 1998 heater frequently will not take its modern equivalent, and that surprise arrives with the old tank already drained and out.
- Measure the route, not just the space. 23″ across means the doorway, the stair turn and the pan all have to take it. An 80-gallon tank that fits the alcove perfectly and cannot get down the basement stairs is a wasted delivery.
- The T&P discharge pipe is not optional and it takes room. It runs from the valve down to within six inches of the floor, in rigid pipe, with no valve and no threaded end. Plan the route before the tank goes in — after it is in place, the run is awkward and it tends to get done badly.
- Short and lowboy tanks buy height by giving up something. They are wider, so the closet has to be wider, and a squat tank stratifies less well — the hot layer at the top is shallower, so usable draw before the water turns cool is slightly less than the gallon figure suggests.
The measurement that catches people out
Not the tank. The ceiling. The anode rod is around 44 inches long and it lifts straight up out of the top, so replacing it wants roughly 94 inches of clear height above the floor. In a basement with seven-foot joists, on a tall tank, there is not room — and the anode is the single component that decides whether the tank lasts eight years or eighteen.
Where the ceiling is short, buy a segmented rod when the heater goes in. Finding out afterwards means draining the tank a second time.
Why the replacement does not fit the old space
The 2015 efficiency standards added insulation to every tank, and changed the technology entirely above 55 gallons. A closet built around a heater from the nineties frequently will not take its modern equivalent — a surprise that arrives with the old tank already drained and disconnected.
Measure the route, not just the alcove
20–23″ across has to pass the doorway, the stair turn and the drain pan. A tank that fits the space perfectly and cannot reach it is still a failed delivery.
Nearby sizes
Read more
- Water Heater Replacement Cost by State — 50 Gallon Gas, All 51Like-for-like is the cheap path. Every change away from it adds a trade, and that is why two quotes on "a new water heater" can differ by three thousand dollars.
- Why Hot Water Runs Out Faster in Winter (And It Is Not a Fault)Nothing broke in October. The water arriving from the street got colder, and that changes both how much hot water you have and how fast it comes back.
- Is a 40 Gallon Water Heater Enough for 2 Bathrooms?Two bathrooms is not a load. Two showers at 7:10am is a load, and the answer changes completely depending on what heats the water.
- T&P Valve Keeps Releasing Water — Thermal Expansion, Not a Bad ValveThe valve is the messenger. Replacing it silences the message for a few weeks and leaves the pressure exactly where it was.