Tankless Water Heater Repair & Installation in Douglasville, GA
Several no-heat causes can be ruled out in a few minutes without opening the heater. In Douglasville, that leaves the technician to test the igniter, flame sensor, gas valve and flow sensor inside the cabinet.
When a gas tankless water heater produces no hot water at all, the cause is usually on a short list: no gas, no power, no ignition, too little flow to start the burner, or a safety control that has locked the unit out. For a Douglasville household facing a cold shower, working through that list in order saves time and avoids replacing parts that were never the problem. For tank-style heaters and other options, see our water heater service overview for Georgia.
Start with the simple checks
- Power: gas tankless units need electricity for the controls, fan and igniter. Check that the unit is plugged in, that its outlet works, and that no breaker or GFCI outlet has tripped.
- Gas: make sure the heater's gas shutoff is in the open position and that the range or furnace still lights.
- Water: confirm the cold inlet and hot outlet valves under the heater are fully open.
- Flow: open a hot tap all the way, since a trickle may fall below the unit's minimum activation flow.
- Display: note any code before resetting anything.
Notice a gas smell at any point? Stop, leave the house and call the gas utility or 911 once you are outdoors.
What the technician tests next
When the basics check out, the diagnosis moves inside the heater. The igniter is tested for a strong spark, the flame sensor is inspected for the buildup that keeps it from proving flame, and the gas valve is checked for the correct signal and output. The flow sensor has to report water movement before the board will start the burner, so a stuck or failed sensor produces exactly this symptom. Fuses on the control board, the fan and the vent pressure switch round out the usual suspects.
When the unit lights but quits
Some heaters ignite, run a few seconds and shut down. That points to the burner not proving flame, gas pressure falling once the burner fires, a vent blockage that trips a pressure switch, or overheating from scale. These faults usually leave a code, and the code history stored in the unit helps narrow the cause. After a hard freeze, a unit whose internal parts froze can refuse to run until they thaw, and freeze damage may leave a leak behind.
Common repairs for a no-heat call
- Cleaning or replacing a flame sensor.
- Replacing an igniter, flow sensor, fan or pressure switch.
- Clearing a blocked vent termination or condensate drain.
- Correcting low gas pressure, which may involve the gas piping rather than the heater.
- Replacing a control board, if parts are still available for the model.
If the heat exchanger has cracked from freezing or corrosion, or the board is discontinued on an older unit, replacement is usually the practical path. You can also compare a storage tank through our gas water heater repair and installation service.
Permits for a replacement in Douglasville
The city's Building Division takes plumbing permit applications online, and a water heater replacement is one of the few permits a homeowner can generally apply for directly. Douglasville sits in Douglas County; if your address is outside city limits, check with the county that serves it.
Questions about a tankless heater with no hot water in Douglasville
Why does my tankless water heater not work during a power outage?
Even gas tankless units rely on electricity to run the control board, the combustion fan and the igniter. Without power, the burner cannot start safely, so no hot water is produced. Some homeowners connect the heater to a backup power source, but that should follow the manufacturer's guidance for the unit's electrical needs.
Why would the kitchen get hot water but not the shower?
If one fixture gets hot water and another does not, the heater is working and the problem lies between it and that fixture. A shower mixing valve with a failed cartridge or a limit stop set too low is a frequent cause. That kind of fix falls under our faucet and valve repair service rather than heater work.
Is it safe to relight a tankless heater myself?
Most tankless units have no standing pilot to relight; they ignite electronically each time hot water is called for. A reset after a power interruption is generally fine, following the manual. Opening the cabinet to work on the gas valve, igniter or burner is not a homeowner task, and any gas smell means leaving the house first.
Booking a no-heat visit
Tell us the brand and model, any code displayed, what you have already checked and whether the heater runs on natural gas or propane. If the unit is outdoors and the weather has dipped below freezing, mention that as well.
Cold taps and a silent heater in Douglasville? Call Alpha at (404) 409-4448 and we will work through it with you.