Professional Tankless Water Heater Repair
A tankless water heater repair brings your hot water back when the unit flashes an error code, runs cold, drips, or shuts off mid-shower. These heaters last a long time, but scale, ignition faults, and worn sensors still take them down, and most fixes need a trained tech and the right parts.
Call a licensed local pro now for a fast quote, with 24/7 help for no-hot-water emergencies.
What a tankless water heater repair covers
A pro reads the error code, tests the gas and water supply, and traces the fault to its real cause. Typical work includes descaling a clogged heat exchanger, swapping an igniter, flame rod, flow sensor, or control board, clearing blocked venting, and resetting the unit after a lockout. Gas, electric, and propane models are covered, indoor or outdoor. A conventional tank unit is a different job, see repair on a standard tank water heater.
Signs your tankless water heater needs repair
- No hot water, or water that swings between hot and lukewarm
- An error code blinking on the display or wall remote
- Banging, humming, or clicking from inside the cabinet
- Water pooling under or around the unit
- The burner igniting, then cutting out after a few seconds
- Weak flow, rusty color, or a metallic smell at the tap
Catch these early. A small scale problem today turns into a failed heat exchanger later, one of the priciest parts on the unit.
Try this first: a 5-minute check before you call
A few quick steps clear the most common false alarms and tell the tech what is happening:
- Confirm power. Check the breaker, and on gas models that the unit is plugged in.
- Confirm gas. The gas valve should be open and other gas appliances running.
- Open both isolation valves and the main water supply fully.
- Clean the inlet filter screen. A clogged screen mimics a flow-sensor fault.
- Note the error code, then power-cycle the unit once.
If the code comes back, call a pro, and never ignore a gas smell.
Common problems we fix and what causes them
| Symptom | Likely cause | DIY or pro |
|---|---|---|
| No hot water, ignition code | Failed igniter or flame rod | Pro |
| Lukewarm or swinging temp | Scale buildup or bad sensor | Pro |
| Low flow at the tap | Clogged inlet screen or scale | Often DIY |
| Unit keeps shutting off | Blocked venting or overheating | Pro |
| Leak at the base | Cracked exchanger or loose fitting | Pro |
Scale buildup is the number one killer. Hard water leaves deposits that choke the heat exchanger, so an undescaled unit fails years early.
Brands and error codes we handle
Techs service every major tankless brand, including Navien, Rinnai, Noritz, Rheem, Bosch, and Takagi. Each brand speaks its own code. A Navien E003 points to ignition failure, a Rinnai 10 flags an air or exhaust blockage, and a Rheem 11 means the igniter did not light. Brand-trained techs and factory parts also keep your manufacturer warranty valid, which a generic repair can quietly void.
What to expect during the repair
Most visits open with a diagnostic: code readout, gas pressure test, and flow check. Many repairs, like a descale, sensor swap, or igniter, wrap up in one visit of one to two hours. A control board or heat exchanger may need a part ordered, so the tech confirms the price first.
What it costs, and repair versus replace
Cost tracks the failed part and its labor: a descale or flush at the low end, a flow sensor or igniter in the middle, a control board or heat exchanger at the top. One rule keeps it simple. If the repair runs past about half the price of a new heater and yours is near the end of its 15 to 20 year life or out of warranty, replacement usually wins. If yours is past saving, a pro can install a new tankless unit and explain what a tankless installation costs.
Same-day and emergency repair
No hot water in winter, a steady leak, or a gas smell is an emergency. Local pros run same-day, 24/7 response for these. The sooner an emergency plumber gets on it, the less damage you face and the lower the repair bill.
Tankless water heater repair FAQ
Why is my tankless water heater not producing hot water? Common causes are a tripped breaker, a closed gas valve, a clogged inlet screen, scale in the heat exchanger, or a failed igniter. Check power, gas, and the filter first, then have a pro read the code.
How often should a tankless water heater be descaled? About once a year, and every 6 to 9 months on hard water. Skipping it is the top cause of early failure, since scale chokes the heat exchanger and cuts your flow and heat.
Can I descale a tankless water heater myself? A flush kit lets handy owners descale, and you can safely reset the unit and clean the inlet screen. Leave gas, igniter, sensor, and board work to a licensed tech.
Get your hot water back today. Call a licensed local pro now for a fast quote, with 24/7 service for no-hot-water and leak emergencies.