Tankless Water Heater Repair & Service in East Bay

Reliable Tankless Water Heater Repair & Service Across East Bay

Are you getting hit with a sudden blast of cold water mid-shower, staring at a blinking error code on the display, or hearing a strange rumbling noise from your unit? These are clear signs that your high-efficiency system is struggling with internal buildup, sensor failure, or combustion issues, and ignoring them will only lead to a complete shutdown. Flow Pro Plumbing is ready to diagnose the exact fault and get your reliable hot water flowing again.

Warning Signs Your Tankless Water Heater Needs Professional Attention

Inconsistent or Fluctuating Temperatures

You step into the shower expecting endless hot water, but instead, you get a quick burst of heat followed by an icy shock. This sudden temperature drop usually points to a failing flow sensor or severe mineral scale coating the heat exchanger. If you ignore this, the unit will overwork itself trying to compensate, driving up your energy bills and risking a cracked heat exchanger.

Digital Display Error Codes

Instead of showing your preferred water temperature, the digital screen is flashing a sequence like code 11, 12, or 90. These codes are a hard stop from the unit's computer, indicating critical issues like flame failure, exhaust blockage, or severe scale buildup. Resetting the unit might clear the screen temporarily, but the underlying mechanical fault will quickly trigger another shutdown.

Strange Rumbling or Screeching Noises

Tankless units are designed to run quietly, so a sudden banging, rumbling, or high-pitched whining is a major red flag. Rumbling usually means hard water minerals have baked onto the heat exchanger, causing the water inside to boil unevenly and violently. Let this go too long, and the stress will physically warp or crack the internal copper piping.

Significant Drop in Water Pressure

When you turn on the hot tap, the water pressure barely trickles out, even though your cold water pressure remains perfectly strong. This happens when calcium and magnesium deposits choke the narrow internal pipes or clog the unit's inlet filter. A restricted flow forces the system to work harder to push water through, which eventually burns out internal components.

Unusual or Foul Odors

You notice a metallic smell, a rotten egg odor, or worse, the distinct scent of burning plastic or exhaust near the unit. Rotten egg smells can mean bacterial growth or a gas leak, while burning odors indicate electrical shorts or dangerous venting failures. These are immediate safety hazards that require an expert to shut down and inspect the system immediately.

Common Causes of Tankless Water Heater Failures

Severe Mineral Scale Buildup

Our regional water supply contains high levels of dissolved minerals that rapidly bake onto the extremely hot surfaces inside your unit. This hard scale acts like insulation, preventing the burner from actually heating the water while simultaneously restricting the flow. We fix this by isolating the unit and pumping a specialized descaling solution through the heat exchanger to dissolve the rock-hard deposits.

Dirty or Failing Flame Sensors

Your system relies on a tiny sensor to confirm that the burner has successfully ignited the gas. Over time, carbon soot and condensation can coat this sensor, tricking the computer into thinking there is no flame and causing it to shut off the gas valve as a safety precaution. We carefully extract, clean, and test this sensor, replacing it if the internal resistance is out of specification.

Blocked Air Intake or Exhaust Venting

A tankless heater needs to breathe massive amounts of air to burn fuel cleanly and safely exhaust the combustion gases. Dust, lint, insect nests, or debris can clog the intake filter or the exterior exhaust pipe, choking the system and triggering an immediate safety lockout. We inspect the entire venting run, clear out obstructions, and verify that the internal fan is pulling the correct draft.

Gas Supply and Pressure Fluctuations

These units require a massive, sudden volume of natural gas or propane the second you open a hot water tap. If your gas regulator is failing, the gas line is undersized, or the meter is struggling, the burner will starve and fail to maintain the target temperature. We hook up a manometer to test the dynamic gas pressure while the unit is firing to pinpoint exactly where the bottleneck is occurring.

What to Expect During Your Repair Visit

When we arrive at your home, we do not just start throwing parts at the problem or guessing based on the symptoms. We hook up our diagnostic tools, pull the exact fault history from the unit's computer board, and test the physical components like the igniter, flow turbine, and gas valves. We check the incoming water pressure, the dynamic gas pressure, and the condition of the heat exchanger to get a complete picture of the system's health.

Once we know exactly what failed and why, we walk you through the findings without hiding behind technical jargon. We provide a clear, upfront breakdown of what it will take to fix the unit, whether that is a deep descaling flush, a sensor replacement, or a new computer board. You will know the exact cost before we turn a single wrench, ensuring there are absolutely no surprises on your final invoice.

After completing the repair, we fire the system back up and run multiple hot water fixtures simultaneously to stress-test the unit. We verify that the temperature remains dead-steady, the exhaust is venting safely, and there are zero leaks inside the cabinet. We leave your utility area cleaner than we found it, delivering the white-glove service that Flow Pro Plumbing is known for.

Tankless Water Heater Repair & Service Coverage Across East Bay

We provide fast, reliable tankless water heater diagnostics and repairs to homes throughout the region. Our fully stocked service vehicles are ready to dispatch to your neighborhood to restore your hot water.

Southern East Bay: Berkeley, Castro Valley, Dublin, El Cerrito, Fremont, Hayward, Livermore, Newark, Oakland, Union City, Albany, El Sobrante, Kensington

Central Contra Costa: Alamo, Concord, Danville, Lafayette, Martinez, Moraga, Orinda, Pleasant Hill, Walnut Creek, Diablo, Pacheco

Northeast Contra Costa & Delta: Antioch, Benicia, Brentwood, Byron, Clayton, Crockett, Discovery Bay, Hercules, Knightsen, Oakley, Pinole, Pittsburg, Richmond

North Bay & Solano County: Fairfield, Suisun City, Vacaville, American Canyon, Napa

San Joaquin Valley: Escalon, French Camp, Lathrop, Lodi, Manteca, Mountain House, Ripon, Stockton, Tracy

Related Services

If your unit is repeatedly breaking down due to old age or severe internal damage, we can help you explore options for traditional Water Heaters as a replacement. We also offer comprehensive System Inspections to keep your plumbing network running efficiently before these emergency breakdowns occur.

Restore Your Hot Water Today

Living with an unreliable tankless water heater is frustrating, but you do not have to put up with cold showers or blinking error codes. Our technicians have the specialized training and diagnostic equipment to fix these complex systems the right way, the first time.

Do not wait for a minor sensor issue to turn into a cracked heat exchanger. Contact Flow Pro Plumbing to schedule your professional repair and get your hot water running flawlessly again.