Las Vegas tankless water heater repair — Rinnai, Navien, Rheem
Tankless water heater repair for Rheem, Navien, Rinnai and Noritz units. Heat exchanger flush, flow sensor, ignition module, error code diagnostics. Descaling service for hard-water Las Vegas homes.
Tankless units display specific error codes on the front panel indicating exactly what's failing. Reading the manual to identify what the code means takes 10 minutes; the fix takes 30-90 minutes depending on the part.
Common Las Vegas error codes: Code 11 (ignition failure — usually spark ignitor or gas valve), Code 12 (flame loss — often flame sensor or gas supply), Code 03 (no water flow — flow sensor stuck), Code 90 (heat exchanger overheating — often scale buildup blocking flow).
For hard-water Las Vegas areas (which is most of the city), annual descaling is the difference between 15-year unit life and 6-year unit life. Scale insulates the heat exchanger, forcing it to work harder and eventually fail. Descaling: $190-$240. Skipped descaling for years, then heat exchanger failure: $1,500-$2,200 to replace. Related in Las Vegas: AC installation, AC repair, and gas piping install.
Diagnostic
The service call
How your Las Vegas HVAC install or service call works — four steps, no surprises
Response + error code
Call answers immediately. Error code from the front panel noted on the phone if you can read it. Same-day response for no-hot-water emergencies.
On-site diagnostic
Error code history review, combustion analysis, flow sensor test, ignition sequence, heat exchanger inspection for scale.
Written quote
Straight pricing for part + labour. Descaling if needed quoted separately. Diagnostic credited on repair.
Repair + verify
Part replaced or descale performed. Combustion re-analyzed. System cycled through 3 hot water demands to verify fix. Error code history reset.
Descaling matters
Las Vegas tankless water heater repair
Hard water carries dissolved calcium and magnesium. When water heats past 60°C in the heat exchanger, those minerals precipitate out as scale. Left alone, scale builds up inside the heat exchanger passages, reducing flow and insulating the heating surfaces.
Symptoms of scale buildup: decreased hot water flow rate, temperature swings during use, and error codes 90 (overheating) or 03 (flow restriction). Left unaddressed, scale eventually cracks the heat exchanger — a $1,500-$2,200 repair or full unit replacement.
Annual descaling flush ($190-$240) uses a food-grade citric acid solution circulated through the unit for 45-60 minutes. Removes accumulated scale, restores flow rate, and prevents heat exchanger damage. Worth every dollar in hard-water Las Vegas neighborhoods. Related in Las Vegas: AC installation, AC repair, and free quote.
$190-$240Descale cost
$1,500-$2,200Skipped descale HX repair
15-20 yrUnit lifespan (maintained)
Related services
Related Las Vegas tankless water heater repair services
Las Vegas HVAC repair tankless water heater repair questions answered
Diagnostic: $149. Flow sensor: $220-$380. Ignitor: $180-$280. Gas valve: $350-$650. Heat exchanger flush (descale): $190-$240. Full heat exchanger replacement: $1,500-$2,200 (usually replace whole unit at this price). Straight pricing.
Common codes: 11 (ignition fail), 12 (flame loss), 03 (no water flow), 05 (low battery/power), 90 (overheat). Full error code list is in the owner's manual. Tell us the code on the phone and we can often predict the repair before arriving.
Three common causes: (1) undersized unit for household demand — no fix except upgrade; (2) undersized gas line — fixable with gas line upsize; (3) scale buildup restricting flow — fixable with descaling. Diagnostic identifies which one.
Annual for Las Vegas homes in hard-water areas (most of the city). Every 18 months for homes with water softeners. Skip descaling and heat exchanger fails in 5-7 years instead of 15-20 year expected life.
Heat exchanger warranty on most tankless units: 12-15 years (Rheem, Navien) or 15 years (Rinnai). Other parts warranty: 1-5 years. We check warranty status during diagnostic and file claims for covered parts.
Rheem tankless was throwing code 90 constantly. Descaled the heat exchanger, replaced flow sensor while there. Full flow rate restored, no error codes for a year now.
S. Fernandes
Descaling recovery
★★★★★
Navien unit had ignition issues at year 8. Under manufacturer parts warranty. They handled the claim, replaced the gas valve, only paid labour.
T. Al-Fassi
Warranty repair
★★★★★
Tankless was struggling with simultaneous demand. Turned out gas line was undersized. They ran a load calc, quoted the upsize as a separate job. Tankless works perfectly now.
M. Osei
Gas line diagnosis
★★★★★
Tankless failed Sunday afternoon. On-call technician answered, arrived within 3 hours, replaced ignitor from truck. Charged the after-hours rate honestly, no surprises.
R. Kumar
Emergency Sunday call
From the blog
Las Vegas HVAC guides — heat pumps, rebates, seasonal maintenance
