No hot water? Start with safe, simple checks.

Start with observations

No hot water? Find out how widespread the problem is.

1. Compare two fixtures safely. Test another hot tap carefully, keeping skin out of the stream because hot water can scald. One cold shower with hot water elsewhere may indicate a fixture or mixing-valve issue rather than a failed heater.
2. Separate no water from cold water. No flow at hot taps is different from normal flow that stays cold. Note whether cold taps work and whether freezing or a water outage is possible. Do not thaw pipes with a flame.
3. Check demand and user settings. Has a tank just supplied several showers? Allow its normal recovery time. Look for vacation mode, schedules or an external error display. Do not raise the water temperature to compensate; excessive settings can cause scalding.
4. Look for visible leaks from a safe distance. Report where the water appears and whether space heat also failed. Do not touch wet controls, cap a relief-valve pipe or restart a leaking or flooded heater. A leak near electrics needs immediate professional attention.

Find your equipment

Water-heating checks by fuel and system type.

Fuel and equipment type are separate: for example, a boiler may burn gas, propane or oil, while an indirect tank uses that boiler’s heat. These checks help describe symptoms; they do not confirm a failed part or promise service for every specialty system.

Know your ignition system

How to approach a pilot light that has gone out.

Some older natural gas and propane appliances have a standing pilot. Many newer furnaces, boilers and tankless water heaters ignite automatically. Electric, heat-pump and oil-fired equipment do not have a gas pilot to relight.

1. Identify the appliance first. Read its model label and the lighting instructions attached to that exact appliance. Find the matching manufacturer manual. If the label is missing, unreadable, or does not describe homeowner relighting, call for service.
2. Check the safety conditions. Do not attempt lighting after a gas odor, repeated pilot failure, flooding, soot, damaged venting or a suspected combustion-air problem. Do not remove a sealed burner cover.
3. Follow the appliance label exactly. Only if it explicitly allows homeowner relighting, follow its OFF position, full waiting period, pilot setting, built-in igniter and control-hold sequence. Timing and controls differ by model; there is no safe universal sequence. Never force a control or improvise with a match or lighter.
4. Stop if the labeled attempt fails. If the pilot will not light, will not stay lit, or goes out again, leave the appliance off as directed by its label and arrange service. Do not repeat attempts or bypass the flame-safety device.

For electronic ignition, do not try to light the burner manually. Record the displayed fault and contact a technician. A pilot that repeatedly goes out needs diagnosis, not repeated relighting.

Manufacturer reference: A. O. Smith pilot-light guidance. Your appliance label and model-specific manual take priority.

Still no hot water? Call with these details.

Have your town and property address, callback number, equipment type, fuel, model number, visible fault code and the time the problem began ready. Explain whether the whole home is affected, whether there is a leak, and whether anyone has already reset the equipment. Only take photos if the area is safe.

For Cape Cod, Plymouth, Wareham and Marion, call (508) 217-7090 to discuss urgency and available service. Online requests are for follow-up and do not guarantee emergency dispatch or an arrival time.

Heat and hot water both out? See No Heat →

Related services: boiler service · furnace service · heat pumps · water-heater repair and replacement · service areas.