Deciding whether to repair or replace a tankless gas water heater depends on the unit's age, repair history, and what a diagnostic actually finds, not a fixed rule of thumb.
Tell us what you need—we’ll call you back fast.
Quick answer
A tankless gas water heater is usually worth repairing if it is under roughly ten years old, has no prior major component failures, and the fault is a single identifiable part such as an igniter, flow sensor, or flame rod. Replacement becomes the more sensible choice once the unit is older, has already had one or two significant repairs, or the heat exchanger itself is affected, since that is the most expensive component to replace and often signals the unit is near the end of its practical service life. A licensed technician's diagnostic is what actually settles the question for a specific unit.
Need a licensed gas fitter for your hot water / boiler? Call CANRO at (604) 359-1081 — residential natural-gas heating and hot water across Metro Vancouver since 1999.
The repair-versus-replace decision for tankless equipment usually weighs three things together: the age of the unit, what has already been repaired on it, and what the current fault actually is. A five-year-old unit with a single failed igniter is a straightforward repair. A twelve-year-old unit with a corroded heat exchanger is a much clearer case for replacement, both because that part is costly relative to a new unit and because it suggests the unit has been under stress for a while.
There is no fixed age at which a tankless unit must be replaced, since service life depends heavily on water quality, maintenance history, and how hard the unit has worked, but many units in the region are giving reliable service into their second decade when properly maintained, and many others show problems earlier if descaling was skipped for years.
These faults are commonly documented as recoverable through a single-part repair, though a technician verifies against the manual for your specific model rather than assuming, since diagnostic paths differ across brands.
| Sign | Why it leans toward replacement |
|---|---|
| Heat exchanger showing corrosion or leaking | Most expensive component; often not economical to repair alone |
| Unit has already had two or more major repairs | Suggests ongoing decline rather than an isolated fault |
| Unit never had scheduled descaling on hard or untreated water | Internal wear likely more extensive than a single visible symptom suggests |
| Repeated ignition failures despite prior repairs | May indicate a deeper issue rather than a single faulty part |
| Parts for the specific model are increasingly hard to source | Repair timeline and cost both increase |
It helps a technician to know roughly how old the unit is, whether it has been serviced or descaled on any regular schedule, and what exactly the household has noticed, such as the unit shutting off mid-shower, taking longer to ignite than it used to, or displaying an error indicator on its control panel. Noting when the problem happens, for example only during high simultaneous demand or only on cold mornings, is useful information that costs nothing to gather and can speed up the diagnostic.
Homeowners should not attempt to open the unit's casing or access the heat exchanger themselves, since this involves gas connections and, on some models, electrical components near water, and is squarely a licensed gas fitter's task.
As a ballpark, not a quote, a full tankless installation in Metro Vancouver commonly runs $3,500 to $7,500. A single-part repair is typically a fraction of that, which is exactly why age and repair history matter so much to the decision: a modest single-part repair, such as an igniter, on a five-year-old unit is an easy call, while a similar repair quote on a thirteen-year-old unit with a history of prior fixes is worth weighing against simply moving to replacement and starting the service-life clock over.
Manufacturer warranty terms vary and should be checked against your unit's certificate, since a covered part can change the economics of a repair significantly, particularly on a unit still within its original warranty window.
Safety note
This equipment burns natural gas and is vented to the outside, so any work on the gas line, burner, venting, or combustion air supply must be done by a Technical Safety BC licensed gas fitter. If you ever smell gas, hear a hissing sound near a gas fitting, or suspect a venting problem, leave the home immediately and call FortisBC at 1-800-663-9911 before doing anything else.
There is no fixed age, but once a unit is past roughly ten to twelve years and has already had a major repair, replacement often becomes the more sensible choice, especially if the heat exchanger is affected.
Rarely. The heat exchanger is typically the most expensive single component, and a leak there usually points toward replacing the unit rather than repairing it.
You can note symptoms like ignition failures, temperature swings, or error indicators, but only a licensed technician's diagnostic can actually confirm whether it's a single-part repair or a sign of broader decline.
Yes, skipped descaling on hard or untreated water is a common contributor to internal wear that shows up later as harder-to-repair problems.
It depends on the manufacturer's terms and how old the unit is; verify against your specific warranty certificate rather than assuming coverage.
A single-part repair is usually a fraction of a full replacement, which as a ballpark, not a quote, commonly runs $3,500 to $7,500 installed in Metro Vancouver.
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.