Ariston Water Heater Reset Button: Where It Is
On this page (6 sections)
The Short Answer: On Ariston electric storage tanks, the reset button belongs to the high-limit safety on the thermostat, behind the front cover. Reaching it means removing a cover over live terminals, so it is a technician’s job, and the safety trips for a reason that needs finding. What an owner can reset is the power: the GFCI, the breaker, or a power cycle on models with a display.
Which reset are you looking for?
The word “reset” covers three different things on Ariston heaters:
| Reset | Where it is | Who should use it |
|---|---|---|
| GFCI outlet or breaker | The outlet the heater plugs into, or the breaker panel | Owner, once |
| Display or control reset (models with a screen) | Power off and on, or a procedure in the manual | Owner, as the manual describes |
| High-limit safety (ECO) on the thermostat | Behind the front cover, on the thermostat | Technician |
Why the high-limit trips
The high-limit safety cuts power to the element if the water gets far hotter than the thermostat setting. It does not trip on its own without a reason. Common causes:
- A thermostat that did not switch off, letting the element keep heating.
- An element shorted to the tank, which can heat regardless of the thermostat and often also trips the breaker or GFCI.
- Power applied to a tank that was not full, which overheats the element in air.
- A loose or overheated connection, sometimes after water got into the compartment.
That is why pressing the button repeatedly is the wrong fix. If the cause is a failing thermostat, each reset lets the water overheat again until the safety catches it. Our guide on why you keep having to reset a water heater goes through this in more detail.
What you can do
- Check the water supply. Open a hot tap and make sure it runs a steady stream. If the heater was recently drained, it must be completely full before power is restored.
- Check for water. Water on the cover, under the heater, or from the relief valve pipe means the heater stays off until the leak is dealt with; see Ariston leaking from the front panel.
- Reset the power once. Press the GFCI reset or switch the breaker fully off and on. On models with a display, follow the reset steps in the manual.
- Give it time. A compact tank takes a while to heat from cold. Check again after half an hour or so.
- If there is still no heat, call a technician. Tell them what you have checked and whether the heater was drained, moved or repaired recently.
For a broader list of causes, see Ariston water heater with no hot water.
What the technician will do
The technician isolates and confirms power is off, removes the cover, and checks whether the high-limit has tripped. Before resetting it, they test the element for a short to the tank and confirm the thermostat switches off at its setting. If both are good and there is no sign of water or overheating, they reset the safety and confirm the heater cycles normally. If either part has failed, they replace it, usually with the thermostat if the element was shorted. A high-limit that will not stay reset, or that shows heat damage, is replaced with the thermostat.
Tankless Ariston models
Electric tankless heaters do not have a tank-style high-limit button for owners. They stop heating and show a code when a safety condition occurs. Turning the power off at the breaker, waiting, and turning it back on clears many lockouts, but only after the cause (low flow, a clogged inlet filter, a supply problem) has been fixed. Check the code in your model’s manual.
Frequently Asked Questions
Q: My Ariston needed a reset once after a power cut. Should I worry? A: A single trip around a power interruption is not unusual. If it trips again within weeks, have the thermostat and element tested.
Q: Can I replace the thermostat myself if the reset keeps tripping? A: Replacing a thermostat means working on line-voltage wiring in a compartment near water. It is a job for a qualified technician, who can also confirm the element is not the real cause.
Manuals and supporting references
These links distinguish general safety information from model-specific documentation. A manual directory helps you locate your unit’s instructions; it does not establish that every model uses the same parts, codes, or test values.
- A. O. Smith: standard electric no-hot-water diagnostic chart (opens in a new tab)Professional diagnostic context for standard electric storage heaters; not instructions to open or test your appliance.
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