Tankless water heater repair in Houston

Ignition codes are the most common call. You open a tap, the fan spins, the unit clicks, and then nothing. We check incoming gas pressure with the burner firing, since a line that reads fine at rest can drop too far under load. Next come the igniter, the flame rod and the gas valve. A flame rod coated in oxide gives a weak signal and the board shuts the burner off after a second or two; cleaning or replacing it is quick. Exhaust and intake codes often trace to a wasp nest or debris in the vent termination outside. Board failures happen too, but they're the last thing we blame, not the first.

If your unit takes longer to heat, makes a kettle-like rumble or throws overheat codes, scale is the likely cause. We close the isolation valves, connect a small pump and hoses to the service ports, and circulate a descaling solution through the heat exchanger for about an hour. Then we flush it with clean water, clean the inlet filter screen, and bring the unit back online. Units installed without service valves need those valves added first, which we can do the same visit. If the unit needs this every few months, adding a softener ahead of it reduces how fast scale returns.

Water that swings hot and cold has a few usual suspects. The cold water sandwich is normal to a point: a short burst of cool water between uses while the burner relights. Long swings are not. A flow sensor clogged with debris can misread demand, a dirty inlet screen chokes flow, and a crossed mixing valve somewhere in the house can feed cold water back into the hot line. We check each one, starting at the unit and working out to the fixtures. Low flow at a single shower may be the shower cartridge, which becomes a shower valve repair rather than a heater problem.