San Jose’s Water Heater Specialist
Water Heater Repair & Installation in San Jose, CA
Same-day tank, tankless, and heat-pump water heater service across San Jose and the South Bay.
Quick Answer
Efficient Water Heaters, Inc. provides same-day tank, tankless, heat-pump, residential, and commercial water heater service across San Jose and the South Bay. Call (408) 470-0191 or request a phone estimate with photos of your current unit.
Phone estimates available. Send a photo of your water heater for faster help.
Licensed CSLB #1008381 · Bonded & Insured · Same-Day Service Available
Credentials & Affiliations
What we do
Specialized Water Heater Services
Residential and commercial work across San Jose, Santa Clara County, San Mateo County, and the South Bay — from same-day repairs to full system replacements.
NEW Tankless Water Heater Installation
Space-saving tankless systems with proper gas sizing, venting, condensate, and recirculation planning.
View ServiceTankless Water Heater Repair
Troubleshooting for ignition issues, flow errors, mineral scale, venting problems, and inconsistent hot water.
View ServiceNavien Tankless Service
Navien tankless diagnostics, descaling, recirculation support, and error-code troubleshooting.
View ServiceNEW Heat Pump Water Heater Installation
Efficient electric water heater options for homeowners planning ahead for Bay Area rule changes.
View ServiceNEW Water Heater Installation
Code-compliant tank, tankless, and heat-pump water heater installation across San Jose.
View ServiceWater Heater Repair
Same-day diagnostics for leaks, no hot water, pilot issues, burner problems, and tankless error codes.
View ServiceWater Heater Replacement
Replace old, leaking, or inefficient units with a properly sized water heater for your home.
View ServiceWater Heater Maintenance
Tank flushing, tankless descaling, safety checks, and preventive maintenance for longer system life.
View ServiceResidential Water Heater Service
Repair, replacement, installation, and maintenance for San Jose homeowners with tank, tankless, and heat-pump systems.
View ServiceCommercial Water Heater Service
Hot water solutions for restaurants, multifamily properties, offices, retail, and commercial buildings.
View Service
Joseph J. Castro
Owner, Efficient Water Heaters, Inc.
- Navien Service Specialist
- Rinnai PRO
- Noritz Certified
- CSLB #1008381
- Bonded & Insured
Why choose a specialist
A focused trade.
A better answer.
Water heaters are our specialty. Unlike general plumbing companies, our main work is tank, tankless, heat-pump, residential, and commercial water heater service. That focus helps us diagnose faster, scope jobs by phone, and install cleaner.
Water heaters are our specialty
Our main work is tank, tankless, heat-pump, residential, and commercial water heater service. That focus helps us diagnose faster and install cleaner.
Licensed, bonded & insured
CSLB #1008381. Permit-ready installs to current San Jose code: seismic strapping, venting, expansion tanks, and gas sizing.
Owner-led by Joseph J. Castro
You speak with a specialist — not a call center. Same-day service available · phone estimates during business hours.
What neighbors say
Real Reviews from South Bay Customers
In their own words — South Bay homeowners describing how Efficient Water Heaters handled their job.
“Had a great experience with the guys at Efficient Water Heaters. Joseph and his employee came out right on time, got to work with no fuss, and a little more than three or four hours later we had a brand new tankless installed in our house. They even swept up the garage cleaner than it was before they got there. Great communication before, during, and afterwards. Would definitely recommend them.”
Chieze O.
San Lorenzo, CA
“I asked a lot of questions about tankless. Joseph was quick in responding and the answers were unbiased and helpful. Marco helped us install the water heater. He is efficient, professional, and the job was very well done. Price is fair — I got the best quote comparing with 2 other vendors who have good reviews on Yelp. Highly recommend.”
Tony C.
Campbell, CA
“We were in a bind. Had no water and couldn't get ahold of anyone on the weekend. Joseph responded immediately. Scheduled an appointment the next day and gave us a beautiful new tankless hot water heater for the same price as the previous person quoted for a 40-gallon. His work was very nicely done and we are very happy with our new efficient water heater.”
Celeste G.
San Jose, CA
“I'm so pleased with these guys. Very quick to pick up the phone, and got us scheduled right away for our new tankless water heater. The technician Marcos was super friendly and very receptive to some tough design challenges. It was important to me that the pipes were hidden in the walls, and he really went the distance to get it right, including working a very long day to install everything.”
Tyler M.
San Francisco, CA
“We texted EWH at 10pm and they called us right away! Our 10-year-old tankless water heater wasn't heating, and Marcus came out first thing the next morning. He had to order parts which came in the next day. He was back quickly to replace them and had our heater back to working. We are very impressed with this company — they are definitely very efficient and friendly too.”
Janet B.
San Jose, CA
“My new house had a tankless water heater without a descaling filter. Tried to call multiple places around but I did not get many responses back. Efficient Water Heaters had prompt and great communication, and I was able to book an appointment right away. Installation was done very quickly and professionally by Martin. I could not be happier!”
Y. W.
San Jose, CA
Reviews shown in customers’ own words. We do not publish star ratings or aggregate ratings on this page.
Enjoyed your service? Tell your neighbors.
Your review helps South Bay homeowners find a trusted water heater specialist — and it takes less than a minute.
Reviews are never incentivized. We earn them by doing great work.
Guides & resources
Know before you call.
The Bay Area 2027 Water Heater Rule
BAAQMD Rule 9-6 changes how certain water heaters can be sold or installed in the Bay Area. San Jose homeowners with older systems should understand replacement options before an emergency failure.
Read the 2027 guide
Repair or Replace Your Water Heater?
Age, leak severity, repair frequency, efficiency, and 2027 rule changes all affect whether repair or replacement makes more sense.
See the decision guide
San Jose Water Heater Permit Requirements
Learn when San Jose water heater replacements may require permits, seismic strapping, venting updates, expansion tanks, or electrical changes.
See permit basics
Tank vs Tankless vs Heat Pump
Compare tank, tankless, and heat-pump water heaters by cost, space, efficiency, hot water output, maintenance, and long-term fit.
Read the comparisonTank · Tankless · Heat Pump
Tank vs Tankless vs Heat Pump Water Heaters in San Jose
| Tank (Gas) | Tankless (Gas) | Heat Pump (Electric) | |
|---|---|---|---|
| Best for | Smaller households, lower upfront cost | High hot-water demand, space savings | Long-term efficiency, electrification rebates, 2027 alignment |
| Typical lifespan | 8–12 years with maintenance | 15–20 years with descaling | 10–15 years |
| Footprint | Closet or garage | Wall-mounted, compact | Tall + clearance + condensate |
| Hot water output | Limited by tank size | Endless within sizing | Limited by tank, slower recovery |
| Efficiency | Standard | High | Very high |
| Maintenance | Annual flush, anode rod | Annual descaling (hard water) | Filter cleaning, condensate check |
| Installation complexity | Like-for-like usually simple | Gas sizing, venting, condensate | 240V electrical, clearance, drain |
| 2027 BAAQMD fit | Install through 12/31/2026 | Install through 12/31/2026 | Compliant with BAAQMD Rule 9-6 long-term |
Tank (Gas)
- Best for
- Smaller households, lower upfront cost
- Typical lifespan
- 8–12 years with maintenance
- Footprint
- Closet or garage
- Hot water output
- Limited by tank size
- Efficiency
- Standard
- Maintenance
- Annual flush, anode rod
- Installation complexity
- Like-for-like usually simple
- 2027 BAAQMD fit
- Install through 12/31/2026
Tankless (Gas)
- Best for
- High hot-water demand, space savings
- Typical lifespan
- 15–20 years with descaling
- Footprint
- Wall-mounted, compact
- Hot water output
- Endless within sizing
- Efficiency
- High
- Maintenance
- Annual descaling (hard water)
- Installation complexity
- Gas sizing, venting, condensate
- 2027 BAAQMD fit
- Install through 12/31/2026
Heat Pump (Electric)
- Best for
- Long-term efficiency, electrification rebates, 2027 alignment
- Typical lifespan
- 10–15 years
- Footprint
- Tall + clearance + condensate
- Hot water output
- Limited by tank, slower recovery
- Efficiency
- Very high
- Maintenance
- Filter cleaning, condensate check
- Installation complexity
- 240V electrical, clearance, drain
- 2027 BAAQMD fit
- Compliant with BAAQMD Rule 9-6 long-term
Rules and rebates can change. Review the full 2027 guide or call for current options.
Where we work
Serving San Jose, the South Bay & Peninsula
Owner-led service across Santa Clara County and San Mateo County — same crew, same standards, every job.
Phone estimate
Send photos.
Get a phone estimate.
Most San Jose water heater repairs, replacements, and tankless issues can be scoped faster when we can see the model number, venting, and install location.
- Same-day responses during business hours
- Phone estimates available
- Licensed, bonded and insured
- No high-pressure upsells
Frequently asked questions
Need Hot Water Back Today?
Call or request a phone estimate. A San Jose water-heater specialist will review your situation and help you decide whether repair, replacement, tankless, or heat-pump service makes sense.
- Licensed CSLB #1008381
- Bonded & Insured
- Open 24/7
Navien Service Specialist · Rinnai PRO · Noritz Certified