Three Types — Very Different Trade-offs
Storage Tank Water Heaters
The proven standard. A 40-50 gallon insulated tank stores hot water ready to use; when it cools below the setpoint, the burner fires. About 80-85% efficient with a recovery rate around 45 gallons/hour. Most affordable to install and the simplest like-for-like swap — we can often complete the job same day. Works in any space that fits the tank. Good for San Francisco homes with existing closet or utility room installs and for most Marin homes.
- 80-85% efficient — solid but not peak performance
- 40-50 gallon typical; ~45 gal/hour recovery rate
- Half-day installation on like-for-like replacements
- Most affordable upfront cost and simplest swap
Best for straightforward replacements
Tankless Water Heaters
Tankless units heat water on demand as it passes through a high-combustion heat exchanger — no storage, no standby heat loss. About 95% efficient and capable of 5-7 gallons per minute. Ideal for San Francisco homes where space is tight — they mount on a wall and can fit in a storage closet. Switching from tank requires gas line and venting upgrades in most cases. Not sure where to mount it? Check out our guide on indoor vs. outdoor tankless heaters.
- 95% efficient — lowest operating cost of the gas options
- 5-7 GPM flow rate; endless hot water supply
- Wall-mounted — frees up significant floor space
- Installation typically 1-3 days depending on upgrades needed
Best for space-constrained SF homes
Heat Pump Water Heaters
Electric units that work like a refrigerator in reverse — pulling heat from surrounding air to warm the water. Extremely efficient at 300-400% vs standard electric, but slower recovery (27 gal/hour at 220v, 9 gal/hour at 110v). They’re taller units that need significant clearance and airflow, making them ideal for Marin garages but challenging in tight SF utility closets. With the upcoming 2027 Bay Area gas water heater phase-out, these are becoming the standard replacement. A good fit for all-electric Marin homes.
- 300-400% efficient vs standard electric resistance
- 27 gal/hour recovery (220v) — significantly slower than gas
- Requires 450+ sq ft clearance and good airflow
- Best value in Marin garages; challenging in SF utility closets
Best for Marin homes with garage space
Choosing the Right Type for Your Home
San Francisco and Marin County have very different home layouts, and that matters when choosing a water heater. In SF, space is the constraint — Victorian flats and Edwardian homes have tight utility closets where a tankless unit’s wall-mount pays dividends. In Marin, you typically have more room, which opens up heat pump options that simply won’t fit in city apartments.
Regardless of location: like-for-like is always simplest and cheapest. If your needs haven’t changed, replacing the same type saves money and complexity. If your family has grown, you’ve added bathrooms, or you want to switch from gas to electric, that’s when the conversation gets more detailed — and we’ll walk you through it honestly.
What We Ask Before Recommending Anything:
- How many people are in the household?
- How many bathrooms and concurrent showers?
- What’s your current fuel type — gas or electric?
- Is there garage or utility room clearance for a heat pump?
- Are you open to a 1-3 day installation, or do you need same-day?
- Is your gas line sized for a tankless unit’s higher BTU demand?
Sizing Mistakes That Cause Problems
Most hot water complaints after installation come down to incorrect sizing — not equipment failure.
Don’t Replace a Gas Tank with an Equal-Size Heat Pump
A 40-gallon gas heater recovers ~45 gallons per hour. A 40-gallon heat pump recovers ~27 gallons per hour. Direct swap = running out of hot water by the second shower. If you can’t make it as fast, you need to store more of it — typically size up to 65 or 80 gallons.
Size to Peak Usage, Not What Was There Before
What was already installed may have been undersized for years. We calculate based on your actual simultaneous demand — number of people, bathrooms, appliances running concurrently. Don’t assume the previous size was correct.
Switching Types Often Requires Infrastructure Upgrades
Tankless units need larger gas lines and different venting. Heat pumps may require a 240v circuit. We assess these upfront so there are no mid-project surprises. Budget for the full scope, not just the unit cost. If you’re also considering heating your home, a combi-boiler can handle both domestic hot water and radiant heating in one unit.
Earthquake Bracing Is Required in Both SF and Marin
California code requires seismic strapping on all tank water heaters. We include proper double-strap bracing on every installation. If your existing tank isn’t strapped, that’s a code violation worth fixing regardless of whether you’re replacing the unit.
Water Heater Services
Installation
We install all types — storage tank, tankless, and heat pump. The key is correct sizing before the order is placed. We come out, assess your space and usage, and give you options at different price points with honest trade-offs explained.
Marin water heater installation
Get an EstimateRepair
No hot water? Lukewarm output? Strange noises or a leaking tank? We diagnose fast and give you a straight answer on whether repair or replacement makes more sense — no pressure to go either direction.
All brands and models serviced
Emergency service available
Book a RepairMaintenance
Annual maintenance extends the life of any water heater — tank or tankless. We flush sediment, check the anode rod, test the T&P relief valve, and inspect for slow leaks before they become failures. Marin’s hard water makes flushing especially important.
Marin water heater maintenance
Schedule MaintenanceWater Heater Questions
How long do water heaters last in San Francisco and Marin?
Storage tanks typically last 8-12 years. Tankless units last 15-20 years with proper annual maintenance (descaling is critical — Bay Area water is mineral-rich). Heat pumps are newer technology but expected to last 10-15 years. Regular maintenance extends the life of any type — see our SF maintenance service or Marin maintenance. If your tank is over 10 years old and failing, replacement usually beats repair.
Should I repair or replace my water heater?
If your heater is under 8 years old and it’s a simple fix — thermostat, heating element, pilot assembly — repair is usually cost-effective. If it’s over 10 years old and needs a major component, replacement makes more sense. We’ll give you an honest recommendation either way. We make just as much on a repair call as a replacement job.
Can I switch from a storage tank to tankless?
Yes. Most tank-to-tankless conversions in SF and Marin require upsizing the gas line (tankless units draw more BTUs), changing the venting configuration, and adding a 120v outlet for the controls. Installation typically takes 1-3 days. We assess all of this before giving you a quote so the final number reflects the full scope of work. See our SF installation service or Marin installation service for more detail.
How much does water heater installation cost?
Like-for-like tank replacement is the most affordable — typically a half-day job with minimal changes to existing connections. Switching to tankless or heat pump costs more due to the infrastructure upgrades required. If you have radiant heating and need a combined solution, a boiler system may be worth comparing. We provide free written estimates with all costs broken down clearly before any work begins.
Do heat pump water heaters really save money?
Compared to standard electric resistance — yes, dramatically. Heat pumps use 3-4x less electricity for the same output. If you’re switching from gas, the savings are smaller and depend on local utility rates. The key is correct sizing: a heat pump running out of hot water will frustrate you far more than whatever you pay in utilities. We size them conservatively.
Do I need a permit for water heater replacement in San Francisco or Marin?
Yes — both San Francisco and Marin County require permits for water heater replacement. We handle all permit applications, scheduling inspections, and final sign-off as part of our service. Proper permitting ensures your installation is code-compliant, which matters for homeowner’s insurance and future property sales. We work with all major brands including Navien, Bradford White, Rheem, and A.O. Smith.
Need a Water Heater? Let’s Figure It Out.
Whether your tank just failed, you’re planning ahead, or you want to make the switch to tankless or heat pump — we’ll come out, look at your space, and give you straight advice on what makes sense for your home and budget.
Get a Free EstimateLicensed & Insured • SF & Marin County • Same-Day Available on Like-for-Like Swaps