Tankless Water Heater Repair in Plano & DFW

A tankless water heater showing an error code or delivering cold water needs a technician who knows the system — not a trial-and-error parts swap. We diagnose the specific fault, quote the fix, and repair it on the same visit in most cases.

Updated: June 15, 2026

Tankless Water Heater Repair in Plano & DFW

Tankless Repair Requires Different Skills

Tank water heaters have a heating element or burner and a thermostat. Tankless units have a flow sensor, igniter, flame sensor, heat exchanger, gas valve, inlet temperature sensor, and — on modern units — a circuit board that monitors all of it and displays error codes when something is off. Properly diagnosing a tankless fault means reading the error code correctly and understanding what it actually indicates, not just replacing parts until something works.

Common Tankless Faults We Diagnose and Fix

Error codes for ignition failure: usually the igniter, flame sensor, or gas supply issue. Scale buildup in the heat exchanger: reduced flow, error codes, or efficiency loss — a descale flush resolves it when caught early. Flow sensor faults: unit won’t fire when hot water is opened. Inlet temperature sensor failure: unit miscalculates temperature rise. Venting blockage: unit shuts down on exhaust overheat. Recirculation pump failures on units with built-in recirculation.

Brands We Service

Rinnai, Navien, Noritz, Rheem, Bradford White, EcoSmart, Takagi, A.O. Smith. If it’s a tankless unit installed in a DFW home, we’ve worked on it.

Everything We Offer

Error code diagnosis (all major brands)
Igniter and flame sensor replacement
Heat exchanger descaling and flush
Flow sensor diagnosis and replacement
Gas valve and pressure testing
Venting obstruction inspection
Circuit board assessment
Recirculation pump service

FAQ

Tankless Water Heater Repair in Plano & DFW — Common Questions

Straight answers before you call.

My tankless water heater shows an error code. What does it mean?

Error codes are brand-specific — a code 11 on a Rinnai means something different than a code 11 on a Navien. We know the code tables for all major brands. Tell us the brand and code when you call and we can often give you a preliminary diagnosis before we arrive.

Why does my tankless water heater go cold in the middle of a shower?

The most common causes: scale buildup in the heat exchanger restricting flow, a failing flow sensor that intermittently loses the signal, or a venting issue causing the unit to overheat and cycle off. We diagnose which it is with the unit running.

Can you descale a tankless water heater?

Yes. We flush the heat exchanger with a descaling solution using isolation valves. If your unit doesn't have isolation valves installed, we can add them as part of the service. In DFW's moderately hard water, annual descaling is recommended to maintain efficiency and prevent failure.

Is it worth repairing an older tankless water heater?

Tankless heaters typically last 15–20 years with proper maintenance. If yours is under 12 years and the failure is a component (sensor, igniter, flow meter) rather than a failed heat exchanger, repair is usually the right call. A failed or heavily scaled heat exchanger on an older unit may make replacement more cost-effective.

Do you work on electric tankless water heaters?

Yes. We service both gas and electric tankless units. Electric tankless faults usually involve heating elements, thermistors, or flow switches — we diagnose and repair these as well.