Water heater repair and replacement for Belmont homes ? tank, tankless, gas, and electric. No hot water, leaks, and thermostat failures get priority scheduling. We diagnose on site, quote before work begins, and install replacements with proper venting, connections, and haul-away of the old unit.
Request service
Fast response — no obligation
10% OFF
Limited Time Offer
Any plumbing service
Call (415) 728-6391 — cannot be combined with any other offer or coupon.
Gas units may fail at the pilot, thermocouple, gas valve, or venting; electric units at breakers, thermostats, or elements; tankless units at flow sensors, scale, or vent errors. We test systematically and quote the repair before swapping parts.
Household size, fixture count, and peak usage drive tank capacity or tankless flow rate. We discuss efficiency tiers, venting requirements, and earthquake strapping so the new unit is code-compliant on day one.
Tankless saves space and can lower gas use when sized correctly. We install major brands with proper gas line sizing and venting ? undersized units cause cold surprises at peak demand.
Every job is completed by licensed plumbers with full liability coverage.
Tank, tankless, gas, and electric — we diagnose no-hot-water issues and install new units to code.
We explain the problem and quote before work begins — no surprise charges.
When a thermocouple or element fixes the issue on a younger unit, we repair. When the tank is rusting through, we show replacement numbers honestly.
Gas water heater replacements in Belmont often require permit and inspection. We include that in the quote so you are not surprised at the end.
Annual flushing on tanks and descaling on tankless units reduce surprise failures. Ask during your service call.
I had a water heater that broke recently. I used ASAP Plumbing and was very satisfied with my experience with them. They came quickly, were responsive, explained everything I needed to know and honored the price they quoted me over the phone. Very professional. I am glad to know that there is a company like ASAP Plumbing I can call on if I need a plumber in the future. I highly recommend them.
Ellen Markoff
Jul 6, 2026
Came home to no hot water. Asked neighbors who to call. ASAP was true to their name. Showed up almost immediately, diagnosed the failed hot water tank, and got a replacement installed very fast. Also fixed a flow issue we had. Good communication throughout the process, which I greatly appreciate.
Andy Berschauer
Dec 8, 2025
Our hot water heater died after reaching the end of its life, and ASAP Plumbing (Kong was our plumber) came the same day and installed a brand new hot water heater for us. They were easy to work with and worked quickly! The original estimate for the job was that it would take 3 hours for 1 person, but they ended up bringing on a second person to help, and the whole thing was done in 1.5 hours. Communication was prompt, service was great!
Sherry Lin
Jul 16, 2025
Quick and responsible service. Don checked and repaired our leaky sink and water faucet adapter the same day that I called for the service. The work was professionally performed with proper cleanup afterward. I also like the fact that he wore shoe covers inside the house without the need for me to ask him to do so. Great work!
Jonathan
Dec 22, 2023
Don was recommended by a friend of mine. He has helped me replace a sink faucet, a toilet, and installed an instant hot water heater. He has been fantastic with each. Always on time, checks in the day before for the appointment, gives quotes beforehand, knows what he is doing and is great at it, will order and bring any pieces you need beforehand, and is very friendly. Highly recommend!
Lydia Simmons
Dec 15, 2022
Donald is a true professional. He seems to always be able to figure out what is wrong and produce a fix in a very short amount of time. I've hired him for toilet jobs where the toilet was clogged or the flush was becoming weak. He was able to diagnose and repair within an hour and charged a fee that was more than reasonable compared to many other places I got quotes from. Another time I hired him to look into why black stuff was coming out of my shower head. He was able to quickly diagnose that it may be just that my water tank needs to be flushed, and BAM! After flushing, the issue never came back. I highly recommend Donald for any of your plumbing needs. He'll know what to do.
Oliver Xia
Dec 15, 2022
They came out and figured out where my water leak was coming from. They also diagnosed another plumbing issue that I did not call for. I was able to get 2 problems solved at one time. I truly appreciate the service! I have them in my contacts now and will refer them for plumbing work.
Tamara Nobles
Feb 18, 2026
I've worked with Donald of ASAP Plumbing several times over the past 4 years and can confidently recommend their services. He's unclogged drains, replaced kitchen sink water valves and garbage disposal, and resolved an active leak in my old rental apartment kitchen. He's prompt to respond to inquiries, shows up during the expected time window, and overall is a very friendly and personable guy.
Linden McGreevy
Jan 22, 2026
No hot water disrupts showers, dishes, and laundry the same day it fails. ASAP Plumbing Pros repairs gas, electric, tank, and tankless water heaters in Belmont — and installs replacements with proper venting, seismic strapping, and haul-away when repair no longer makes financial sense.
Thermocouples, elements, thermostats, and valves are common fixes on younger units. Rusty tanks, repeated leaks, and units past their rated lifespan often favor replacement. We show both paths with real numbers. See equipment options on our water heater repair & replacement page.
Fixture count and peak demand drive tank gallons or tankless flow rate. Undersized tankless units cause cold surprises; oversized tanks waste energy. We size for how your home actually uses hot water.
Gas replacements frequently require permit and inspection. Earthquake strapping and correct venting are not optional extras — they are part of a safe install we include in the quote.
Call (415) 728-6391 or contact us for water heater service in Belmont. Say whether you have no hot water, a leak, or strange noises so we prioritize and bring the right parts.
No-hot-water calls are prioritized for same-day or next-day service.
Yes ? major brands serviced; descaling and flow sensor issues are common fixes.
We compare repair cost, unit age, and efficiency. Tanks over 10?12 years often favor replacement.
Most tank swaps finish in half a day; tankless may take longer if venting or gas line upsizing is needed.
Yes ? removal and disposal are included in replacement quotes.
We size by household fixtures and peak demand for tanks or flow rate for tankless.
Gas replacements often require permit and inspection; we handle that process.
We serve San Francisco, Daly City, San Mateo, South San Francisco, San Bruno, Millbrae, and communities throughout San Mateo County. Call (415) 728-6391 to confirm service for your address.
Ready when you are
Plumbing emergency? We're on the way.
Call (415) 728-6391 or request service online — 24/7, every day of the year.
