Find the Source First
John Wood is a long-standing Canadian water heater brand, and you will find these tanks in plenty of Greater Vancouver basements and utility rooms. When one starts leaking, the first job is always the same: figure out exactly where the water is coming from, because that single fact tells you whether it is a simple repair or time for a new tank.
Dry the unit and the surrounding floor completely, then watch where moisture comes back. The leak almost always traces to one of four areas: the bottom drain valve, the T&P relief valve and its discharge pipe, the top water connections, or the steel tank itself.
Since water runs down and collects at the lowest point, do not assume a puddle means the tank is gone. Trace the wet path upward to the highest point where dry becomes wet, and that is the true origin.
Common Reasons John Wood Tanks Leak
T&P relief valve drips. This safety valve can weep from a worn seat, or because system pressure or temperature is too high. With Metro Vancouver's variable water pressure, an expansion-related drip is common. The cause should always be checked rather than masked.
Drain valve leaks. The valve at the base may not reseal after a flush or can loosen over time, which is usually a low-cost fix.
Loose or corroded fittings. Years of heating and cooling cycles, plus dissimilar-metal contact at the connections, can produce slow leaks at the top of the tank.
Tank corrosion. Like all tank heaters, John Wood units use a sacrificial anode rod to protect the steel. Once it is depleted, the tank corrodes from within and eventually leaks through the shell. That kind of leak is not repairable and signals replacement.
What to Do and What to Leave to a Pro
If the leak is active, shut the cold-water inlet valve on top of the heater to stop it refilling, and set a gas model's control to OFF or PILOT, or switch off the breaker on an electric unit. This makes everything safe to evaluate.
Place dry paper towel under each suspect point and check after 30 to 60 minutes to pinpoint the source. A clearly loose connection can be gently snugged, but never force a fitting, because cracking it turns a small leak into a bigger one.
Gas valves, burners, and controls are off-limits for DIY. In BC, gas appliance work must be done by certified gas fitters, both for safety and to protect any remaining warranty. When the fix goes beyond tightening a fitting, call for professional help.
One thing worth knowing about John Wood tanks is that the anode rod is the key to longevity. If your unit is around five or six years old and has never had the anode checked, it may be most of the way through its protective life, which is often why tanks of that vintage start to weep. When we service a leak that turns out to be a fitting rather than the tank, we will usually look at the anode at the same time so you get the most life out of the unit before replacement becomes necessary.
Repair or Replace, and Who Handles It
Leaks at the valves, drain, or fittings are usually repairable. A leak from the tank body is not, and on a unit beyond roughly 10 years, replacement is the wiser investment. Many John Wood residential tanks carry a 6-year limited tank warranty, with extended options on some models, so check the serial number for the manufacture date before paying out of pocket.
Water heaters in Greater Vancouver are serviced by our parent company, CanroHeat. Repair costs range from a small valve or fitting repair up to a complete tank replacement, with same-day swaps often available. We provide an exact quote only after seeing the unit, so call 604-359-1081.
Should you ever smell gas near the heater, do not touch switches or flames. Leave the home, call FortisBC at 1-800-663-9911 or 911 from outside, then call us at 604-359-1081.