“Reset” means two different things depending on whether your Rheem is electric or gas. On an electric unit it’s the red high-temperature cutoff button, the ECO, sitting on the upper thermostat behind the access panel, and you only press it with the breaker shut off. On a gas unit there’s no reset button like that. What people call resetting is relighting the pilot or restarting the burner using the steps printed on the heater itself. The bigger point for both: if you have to reset it more than once, something is wrong underneath, and resetting again won’t fix that.
Electric: the reset is the ECO, and the breaker comes off first
The reset button on an electric water heater is a safety switch called the ECO, short for emergency cut-off, also called the high-limit. It’s a small red button built into the upper thermostat, hidden behind the upper access panel and a layer of insulation. It trips and kills power to the elements when the water climbs past a safe temperature. That’s the tank protecting you from scalding water and worse.
How do you know it tripped? On an electric heater a tripped ECO usually means no hot water at all, because it cuts both elements at once. If you’ve still got some warm water, you’re probably looking at a single failed element or a thermostat, not the ECO.
If you’re going to press it, the breaker feeding the water heater goes off first, every time. There’s 240 volts sitting behind that panel and the ECO is right next to live terminals. Turn the breaker off, then you can pull the panel, fold the insulation back, and press the red button until it clicks.
Here’s the part most people skip. The ECO didn’t trip for no reason. It tripped because the water actually got too hot. The usual causes are a thermostat set way too high, a thermostat that’s failed and won’t shut the element off, or an element that’s shorted and heating nonstop. Press the reset once to get hot water back, sure. But if it trips again that day, or again that week, stop pressing it. Each trip is the safety doing its job because the real fault is still there. Replacing a thermostat or an element means testing live circuits and draining the tank, so that’s where I’d have you call instead of keep resetting.
Gas: there’s no reset button the same way
A gas Rheem doesn’t have that red ECO button. When people say they want to reset a gas water heater, they almost always mean the pilot went out and they need to relight it, or the burner quit and they want to restart it.
Don’t guess at the sequence. Rheem prints the lighting instructions right on the unit, usually on a label by the gas control valve, and the steps differ between an older standing pilot and a newer push-button igniter model. Follow that label. One thing it will tell you that’s worth repeating: turn the gas control to off and wait several minutes before you try to relight, so any gas can clear. Don’t shortcut that wait.
If the pilot lights but drops out as soon as you let go, or it keeps going out over and over, that’s usually the thermocouple or flame sensor not holding the gas valve open. Cleaning or replacing that is a pro job on a gas appliance. And if you ever smell gas, don’t fiddle with anything. Leave, and call your gas utility from outside.
When one reset turns into a pattern
A reset is meant to be a one-time recovery. The tank hit a fault, the fault cleared, you reset, you’re back in business. What’s not normal is resetting the same heater again and again. On electric that points at a thermostat or element. On gas it points at the thermocouple, the gas valve, or a venting problem. None of those get better by hitting reset one more time, and a couple of them are the kind of thing you don’t want to ignore.
When to call us
If the breaker’s on, you’ve reset once, and you still have no hot water, or the ECO keeps tripping, or a gas pilot won’t stay lit, that’s our cue. We cover the whole Bay Area and can usually get out same or next-day. Book at adriumservice.com or give us a call. We’ll find out why it keeps tripping instead of just resetting it and walking away. I stand behind the work, even when I’m not the one knocking on your door.