No hot water from a gas-fired A. O. Smith tank usually traces back to the pilot, gas supply, thermostat, or sediment buildup, not the tank itself.
Tell us what you need—we’ll call you back fast.
Quick answer
A natural-gas A. O. Smith water heater that produces no hot water is most commonly dealing with a pilot or ignition failure, an interrupted gas supply, a failed thermostat or gas control valve, or heavy sediment insulating the burner from the tank. A homeowner can safely check the obvious things first; anything involving the gas valve, burner assembly, or venting should go to a Technical Safety BC licensed gas fitter.
Need a licensed gas fitter for your tank water heater? Call CANRO at (604) 359-1081 — residential natural-gas heating and hot water across Metro Vancouver since 1999.
Before assuming the worst, confirm the basics. Check that the gas supply valve to the water heater is fully open, that no other gas appliance in the home lost service at the same time, and that a breaker or switch feeding an intermittent-pilot ignition module has not tripped. On older standing-pilot units, look through the sight glass for a lit pilot flame. If the pilot is out, most A. O. Smith manuals walk through a relight sequence printed on the tank jacket, but if it will not stay lit after two attempts, stop and treat it as a service issue rather than repeating the sequence.
It also helps to run a hot tap for a minute and listen at the tank. A working burner produces a soft rumble as it fires; silence with cold water flowing points toward ignition, gas supply, or control failure rather than a delivery problem elsewhere in the plumbing.
| Cause | What It Looks Like | Homeowner-Safe Check? |
|---|---|---|
| Pilot or ignition failure | No flame, clicking igniter with no ignition | Visual check only, do not force relight repeatedly |
| Closed or restricted gas valve | Water heater and possibly other gas appliances affected | Yes, confirm valve handle is parallel to the pipe |
| Faulty thermocouple or flame sensor | Pilot lights but will not stay lit | No, gas control component, licensed tech only |
| Failed gas control valve or thermostat | Pilot lit, burner never fires or overheats | No, licensed tech only |
| Heavy sediment on tank bottom | Popping or rumbling sounds, slow recovery | No, requires flush by a technician |
| Crossed hot/cold lines | Cold water at hot tap, hot water elsewhere | Yes, a plumber can trace this without gas work |
CANRO services tanks across Burnaby, Vancouver, and the wider Metro Vancouver region, and sediment-related no-heat calls are less frequent here than in communities on well water, since Metro Vancouver's reservoir supply is comparatively soft. That said, older character homes in East Vancouver and parts of Burnaby still run galvanized or aging copper branch lines that can shed debris into a tank over the years, and a water heater installed more than eight to ten years ago is a reasonable candidate for sediment buildup regardless of source water. Fraser Valley properties on well water tend to accumulate sediment faster and may need more frequent tank flushing.
Damp coastal conditions can also accelerate corrosion at gas fittings and flue connections on older installs, which is another reason a no-heat call sometimes turns into a broader inspection rather than a single-part swap.
A single failed component, such as a thermocouple, flame sensor, or igniter, on a tank under roughly eight years old is usually worth repairing. Once the gas control valve itself has failed, or the tank shows rust weeping from the bottom seam, replacement is typically the more sensible path, since a new control valve on an aging tank is a costly repair on a unit nearing the end of its service life anyway. A. O. Smith documents expected service factors for its product lines, but actual lifespan varies with water chemistry, installation, and maintenance, so treat any age-based estimate as a general guide rather than a guarantee.
If replacement is the right call, a natural-gas tank swap is generally quoted after CANRO sees the existing venting, gas line sizing, and clearances in person; a tankless install runs roughly $3,500 to $7,500 as a ballpark, not a quote, while a standard gas storage tank's cost depends on tank size, vent type, and access.
Safety note
If you smell gas at any point, leave the home immediately and call FortisBC at 1-800-663-9911 from outside before doing anything else. Never attempt to repair a gas control valve, thermocouple, or venting yourself; gas water heater work in BC must be performed by a Technical Safety BC licensed gas fitter. CANRO holds gas licence LGA0043870.
A lit pilot with no hot water usually points to a failed gas control valve, a stuck thermostat, or in rare cases a burner that is not receiving gas even though the pilot flame is present. This needs a licensed technician to diagnose the control components safely.
Most A. O. Smith tanks have a relight procedure printed on the jacket that homeowners can follow. If the pilot will not stay lit after a couple of attempts, stop and call a licensed gas fitter rather than repeating the process.
Metro Vancouver's reservoir water is comparatively soft, so sediment buildup tends to be slower here than in well-water areas, but it can still occur over many years, especially in older tanks or homes with aging pipe material.
Run a hot tap and listen for the burner firing. If the burner never fires with cold water flowing, the issue is almost always at the water heater rather than elsewhere in the home's plumbing.
No. Gas control valves are safety-critical components and gas work in BC legally requires a Technical Safety BC licensed gas fitter.
Cost depends on tank size, vent type, and site access, and is best quoted after a short in-home assessment; a tankless install runs roughly $3,500 to $7,500 as a ballpark, not a quote.
Family-run, TSBC-licensed (gas LGA0043870 · boiler LBP0046450), serving Metro Vancouver homes since 1999. Residential, natural gas only.
Call (604) 359-1081 Email info@canroheat.ca“Canro does an amazing job! Super professional and skilled with everything—boilers, furnaces, and AC. Always a pleasure working with them!”
“Five stars for Canro. We needed a replacement of a 30-year-old boiler. A new high-efficiency unit was installed—clean, professional work.”
“I can’t speak highly enough about George, who was recommended for a boiler service call for my parents’ home. George is excellent.”
25+ years keeping Metro Vancouver homes comfortable. Honest advice, upfront pricing, work that lasts.