Water heater smells like something burning

Symptoms

• Burning or acrid smell near the water heater
• May be strongest right when the unit is heating
• No visible smoke, or a slight haze near the unit
• Smell might be new or have started recently

Likely causes

• CommonDust burning off the burner or elements after a period of disuseThis is common right after turning on a heater that's been idle, like at the start of a season, and usually clears within minutes.
• PossibleElectrical fault in wiring, an element, or a thermostatOverheated or arcing electrical connections can produce a distinct acrid smell.
• PossibleDebris or an object too close to the burner or flueStored items placed too close to a gas unit can scorch.
• Less commonFailing gas valve or venting issue causing incomplete combustionSerious but less common, this can create unusual smells along with soot.

What to do

1. If it's the first time running the heater after a long idle period, monitor for a few minutes; a brief dust-burning smell that fades is usually harmless.
2. Check that nothing flammable or non-heat-rated is stored touching or very close to the unit.
3. For electric units, turn off the breaker if the smell is strong or persistent and don't restore power until it's checked.
4. For gas units, check for any gas smell in addition to the burning smell, which would call for immediate evacuation and a call to the gas utility.
5. Look around the base and top of the unit for any soot, scorch marks, or discoloration.
6. If the smell doesn't clear quickly, gets stronger, or you see any scorch marks or smoke, shut the unit down and don't use it again until inspected.

Tools and parts

• Flashlight

When to call a pro

Have an electrician or gas technician inspect the unit if the burning smell persists beyond a brief startup period or you find any scorch marks.

Safety