Tankless Water Heater Installation & Repair in San Jose
Navien Service Specialist, Rinnai PRO and NORITZ certified. Efficient Water Heaters Inc. has installed, repaired and descaled tankless systems across San Jose, Santa Clara County and San Mateo County since 1997 — and we answer the phone 24/7.
Open 24/7 · CSLB License #1008381 · Owner Joseph Castro
Quick Answers
- Who installs tankless water heaters in San Jose?
- Efficient Water Heaters Inc., owned by Joseph Castro, CSLB License #1008381. We have installed and serviced tankless systems across San Jose and the South Bay since 1997 and answer the phone 24/7 at (408) 470-0191.
- Which tankless brands do you service?
- Navien, Rinnai and NORITZ. We are a Navien Service Specialist and hold Rinnai PRO and NORITZ certification, so installation, repair and warranty-compliant maintenance are all handled in house.
- How often does a tankless heater need descaling in San Jose?
- Once a year on untreated San Jose water, or about every two years in a home with a properly sized water softener. Manufacturers require documented descaling to keep scale-related warranty coverage.
- How fast can you get out to a no-hot-water call?
- We take calls 24 hours a day, seven days a week at (408) 470-0191, and most San Jose and Santa Clara County addresses fall inside our daily route.
What We Do for Tankless Systems
Tankless installation & replacement
New Navien, Rinnai and NORITZ units sized to your home's hot water demand, with gas, venting and water lines built to code and permitted through the city.
Tankless repair & diagnostics
Error codes, no hot water, ignition faults, flow-sensor problems and short-cycling — diagnosed by a contractor who works on these units every week.
Descaling & annual maintenance
Hard water scale is the number one cause of tankless failure in the South Bay. We flush the heat exchanger, clean the inlet filter and check combustion.
Warranty-compliant setup
Manufacturers set maximum hardness limits and maintenance requirements. We install and document the work so scale-related warranty coverage stays intact.
Hard Water Is Why Most South Bay Tankless Units Fail Early
San Jose Water publishes hardness of 11–26 grains per gallon on local groundwater and 4–12 grains per gallon on surface water. Anything above 7 grains per gallon is hard, and those minerals turn into scale on a tankless heat exchanger — the exact surface the burner heats. Scale means longer run times, higher gas bills, error codes, and a unit that quits years early.
That is why we pair tankless work with whole-home water softener installation. Soft water keeps the heat exchanger clean and keeps you inside the hardness limits Navien, Rinnai and NORITZ set for warranty coverage.
Tankless Water Heater FAQs
- How much does tankless water heater installation cost in San Jose?
- It depends on the unit size, whether gas and venting need upgrading, and whether you're converting from a tank. Joseph gives a firm, itemized price before any work begins — call (408) 470-0191.
- Do you repair Navien, Rinnai and NORITZ tankless heaters?
- Yes. Efficient Water Heaters Inc. is a Navien Service Specialist and is Rinnai PRO and NORITZ certified, so we install and service all three brands.
- Why does hard water damage a tankless water heater?
- San Jose water runs 11–26 grains per gallon on local groundwater. Those calcium and magnesium minerals bake onto the heat exchanger as scale, which blocks flow, drops efficiency and triggers error codes. A water softener plus annual descaling prevents it.
- How often should a tankless water heater be descaled?
- About once a year on hard South Bay water, or every two years if the home has a properly sized water softener. Manufacturers require this maintenance for warranty coverage.
- What areas do you cover?
- San Jose, Santa Clara, Sunnyvale, Campbell, Los Gatos, Cupertino, Milpitas, Saratoga, Morgan Hill, Gilroy, Mountain View, Fremont and San Mateo County cities including San Mateo, Redwood City, Menlo Park and Burlingame. We answer the phone 24/7.
Need a Tankless Water Heater Installed or Repaired?
Call Joseph today: (408) 470-0191
Call (408) 470-0191