Best Water Heater Leak Detectors
An alarm tells you. A shutoff valve does something about it. The difference matters most when you are away.
Heat & Tap earns a commission on qualifying purchases made through the Amazon links on this page, at no extra cost to you. Commission does not decide what we recommend or how we rank it. Full disclosure.
A Govee WiFi sensor with a 100 dB alarm and email alerts is the cheapest useful protection — but it only tells you. A Flo by Moen shutoff actually closes the main, runs a daily micro-leak test sensitive to one drop per minute, and is what you want if you travel. A Rheem Gladiator tank has shutoff built in, limiting a leak to about 20 ounces.
Water heaters fail wet. The common failure is not a burst but a slow weep from a seam or a fitting, which is worse in one specific way: it goes unnoticed. A tank that lets go floods a floor and you deal with it. A tank that weeps a cup an hour behind a closet door rots a subfloor over six months.
So leak detection is less about catastrophe and more about catching the quiet failure early. The three approaches below differ in how much they do once they notice.
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 | Govee WiFi water leak detectorThe cheapest useful leak alarm: a 100 dB siren plus a push and email alert, with one gateway covering up to 20 sensors around the house. | Cheap early warning | Check price on Amazon No live price feed on this site, so we show none. #ad |
| 2 |  Flo by Moen smart water shutoffThe step up from an alarm: it sits on the main, runs a daily micro-leak test sensitive to a single drip per minute, and closes the valve itself when something lets go. | Whole-house automatic shutoff | 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 |
The picks in full
Pick 1 — Cheap early warning
Govee WiFi water leak detector
The cheapest useful leak alarm: a 100 dB siren plus a push and email alert, with one gateway covering up to 20 sensors around the house.
| Alarm | 100 dB, three selectable levels, mutable |
|---|---|
| Alerts | App push and email |
| Capacity | Up to 20 sensors per WiFi gateway |
| Current model | GoveeLife 1s rates a 105 dB alarm and 1,804 ft range |
What is good
- A siren loud enough to hear from another floor
- Email alerts mean you find out while you are away, not when you get back
- One gateway covers the heater, the washing machine and the dishwasher
- Cheap enough to put three around the house
What is not
- It alerts, it does not shut the water off
- Needs working WiFi and a live gateway to send anything
- Battery powered, so it needs checking once a year
Skip it if: Skip it as your only protection if the heater sits above a finished ceiling and you travel. An alert you cannot act on for three days is not protection — that case wants an automatic shutoff valve.
No live price feed on this site, so we show none. #ad
Specifications above from GoveeLife water leak detector 1s product page. We have not tested this unit ourselves.
Pick 2 — Whole-house automatic shutoff
Flo by Moen smart water shutoff
The step up from an alarm: it sits on the main, runs a daily micro-leak test sensitive to a single drip per minute, and closes the valve itself when something lets go.
| Function | Whole-home monitoring with automatic shutoff |
|---|---|
| Detection | Daily micro-leak test; identifies leaks as small as one drop per minute |
| Alerts | App, phone call and email |
| Requirements | 2.4 GHz WiFi and an AC outlet within 10 ft |
| Sizes | 3/4 in, 1 in and 1-1/4 in |
What is good
- It closes the valve, which is the only thing that limits damage when you are away
- A micro-leak test catches the slow failures that rot a subfloor before anyone notices
- Phone-call alerts for people who do not watch app notifications
- Some insurers discount for a monitored automatic shutoff
What is not
- It installs on the main, which usually means a plumber and a shutoff of the whole house
- Needs a power outlet within 10 feet of the main
- Far more expensive than a puck sensor
Skip it if: Skip it if your water main is in a crawlspace with no power. Running a circuit to the main is frequently the larger half of this job, and a pan plus a 100 dB sensor covers the water heater itself for a fraction of the cost.
No live price feed on this site, so we show none. #ad
Specifications above from Moen Flo Smart Water Monitor and Shutoff, 900-006; Home Depot listing, Moen Flo 1 in shutoff. 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.
Three levels of protection
| Alarm sensor | Automatic shutoff valve | Tank with built-in shutoff | |
|---|---|---|---|
| Detects | Water on the floor where the puck sits | Flow anomalies and micro-leaks on the main | Leaks at the tank |
| Alerts | 100 dB siren, app, email | App, phone call, email | Audible alarm plus app |
| Closes the water? | No | Yes, the whole house | Yes, the tank's own supply |
| Protects the rest of the house? | No | Yes | No |
| Install | Put it on the floor | Plumber, on the main, with power nearby | It is the water heater |
| Needs WiFi? | For remote alerts, yes | Yes, 2.4 GHz | For app alerts |
| Sensitivity | Pooled water | One drop per minute | Tank leak, limited to about 20 oz |
The cheap option, properly assessed
The Govee WiFi water sensor gives you a 100 dB alarm with three selectable levels, app and email alerts, and one gateway covering up to 20 sensors. The current GoveeLife 1s model rates a 105 dB alarm and 1,804 feet of range.
At that price the sensible move is three of them: one in the water heater pan, one behind the washing machine, one under the dishwasher. Those are the three appliances that flood American houses, and a gateway covering all three costs less than one hour of a plumber's time.
Its honest limits: it needs working WiFi and a live gateway to send anything, it is battery powered so it needs checking annually, and it does not close the water.
The whole-house option
Flo by Moen sits on the main and monitors flow. Its FloSense technology learns the household's usage pattern and shuts the water off when something is running that should not be. It runs a daily micro-leak test capable of identifying leaks as small as a single drop per minute, and alerts by app, phone call and email.
Two practical requirements that decide whether this is feasible: it installs on the main, which usually means a plumber and shutting the house down for an hour; and it needs 2.4 GHz WiFi plus an AC outlet within 10 feet. If your main is in a crawlspace with no power, running that circuit is frequently the larger half of the job.
It protects the whole house rather than just the heater, which is the honest argument for the cost. Some insurers also discount for a monitored automatic shutoff — worth asking before you buy.
Or buy the protection with the tank
The third row in the table is a water heater rather than an accessory, and it belongs here. The Rheem Gladiator has 360-degree LeakSense detection with a factory-fitted automatic shutoff valve that limits a leak to no more than 20 ounces, and the Rheem ProTerra heat pump unit has the same system.
Twenty ounces is a remarkable number — it is a wet patch, not a claim. If you are replacing the heater anyway and it sits above a finished floor, paying for integrated detection is better value than bolting it on afterwards. Best electric water heaters.
Where to put a sensor
- In the drain pan, not beside it. The pan is where the water goes first.
- At the lowest point of the floor in the room, which is where it goes second. Water finds the low spot before it finds the door.
- Under the relief valve discharge, if that terminates in the same space.
- Behind the washing machine and under the dishwasher too, since you already own the gateway.
- Not on top of the heater, where it will detect nothing until the ceiling is already involved.
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
What the device does once it detects something, then detection sensitivity, then install burden, then whether it protects anything beyond the heater. We have not tested these devices. How we pick.