Tankless Water Heater Repair in the Tri-Valley
Experienced Technicians. Fixed-Rate Pricing. 900+ Five-Star Reviews.
When your tankless water heater flashes an error code or stops producing hot water, you need a technician who works on these units every day. Barnett Plumbing & Water Heaters diagnoses and repairs all major tankless brands across Pleasanton, Dublin, Livermore, San Ramon, Danville, and the surrounding Tri-Valley.
Common Tankless Water Heater Problems
Tankless units are reliable, but they are not maintenance-free. The most common service calls we see involve mineral scale buildup, flow sensor failures, ignition problems, and error codes that lock the unit out of operation.
Scale Buildup and Descaling
Tri-Valley water is moderately hard, and mineral deposits accumulate inside the heat exchanger over time. Reduced hot water output, fluctuating temperatures, and specific error codes (like Rinnai's LC code or Navien's E003) are all signs that descaling is overdue. A professional flush restores flow and efficiency.
Flow Sensor and Ignition Failures
If the unit clicks but does not fire, or if it shuts off mid-shower, the flow sensor or ignition assembly may need attention. Flow sensors detect water movement and tell the unit to fire. When they fail or read incorrectly, you get inconsistent heating or no heat at all.
Error Codes and Control Board Issues
Modern tankless heaters display diagnostic error codes on a small control panel. Some codes point to simple fixes like a clogged intake filter. Others indicate deeper electrical or gas supply problems. Our technicians carry manufacturer diagnostic tools and replacement parts for the most common repairs.
Tankless Unit Acting Up? Schedule a Repair Today.
Brands We Service
We repair all major tankless brands, including:
- Rinnai
- Navien
- Takagi
- Rheem
- A.O. Smith
Our technicians are factory-trained and carry common replacement parts on the truck, so most repairs are completed in a single visit.
Preventive Maintenance: The $99 Water Heater Flush
The best way to avoid costly tankless repairs is annual descaling. Our $99 Water Heater Flush clears mineral buildup from the heat exchanger, checks the inlet filter, and verifies that the unit is operating within manufacturer specifications. It takes about an hour and can add years to your system’s lifespan.
Many of the repair calls we see could have been avoided with regular flushing. If it has been more than a year since your last service, scheduling a flush now is a smart move.
What to Expect During a Service Call
We offer 3-hour arrival windows, Monday through Saturday, 7 a.m. to 5 p.m. You will receive a courtesy call when the technician is headed your way. After diagnosing the issue, we provide a fixed-rate quote for the repair before any work begins. No hourly billing, no open-ended charges.
Tankless Water Heater Repair FAQs
My tankless water heater is showing an error code. What should I do?
Write down the code and turn off the unit. Some codes clear with a simple reset, but others indicate a component failure that needs professional attention. Call us with the brand, model, and error code, and we can often tell you over the phone whether it is safe to reset or if you need a service visit.
How often should a tankless water heater be flushed?
At least once a year. In areas with harder water, every six months is better. Regular descaling protects the heat exchanger and keeps your unit running at full efficiency. Our $99 Water Heater Flush covers the full service.
Can you repair any brand of tankless water heater?
We service all major brands: Rinnai, Navien, Noritz, Takagi, Rheem, A.O. Smith, and others. Our trucks carry common parts for these manufacturers, so most repairs are completed in one visit.
Is it worth repairing an old tankless unit or should I replace it?
Most tankless water heaters last 20 years or more. If your unit is under 15 years old and the repair cost is reasonable relative to a new installation, repair usually makes sense. We will give you an honest assessment and let you decide.
Do you offer same-day tankless repair?
We often have same-day or next-day availability, depending on the schedule. Our service hours are Monday through Saturday, 7 a.m. to 5 p.m. Call us and we will get you the earliest available window.