First 10 Minutes: Stop the Damage
When you find water pooling under your boiler, act in this order. First, shut off the water supply to the boiler. On most Greater Vancouver hydronic systems there is an isolation valve on the cold-water feed (the small pipe with the pressure-reducing valve). Turn it clockwise until it stops. This prevents the system from continuously topping itself up and feeding the leak.
Second, turn off the power. Switch the boiler off at its service switch or flip the dedicated breaker. Water and electrical components are a dangerous mix, and powering down also stops the burner from firing against a dropping water level.
Third, contain the water. Slide a shallow tray, towels, or a bucket under the drip and move anything valuable away from the area. Water from a heating system is often warm and can be discoloured or rusty, so protect flooring and drywall right away. With those three steps done, the emergency is stabilised and you can assess calmly or call us at 604-359-1081.
What Causes Most Boiler Leaks
The most common source we find in Lower Mainland homes is a failed or weeping pressure relief valve (PRV). This safety valve opens when system pressure climbs too high, usually because of a waterlogged expansion tank or an overfilled system. The leak shows up at the valve body or at the end of its copper discharge pipe.
Pump and pipe-fitting seals are the next most frequent culprit. Circulator pump gaskets, pump flange O-rings, and threaded joints all dry out and seep over years of heating and cooling cycles. A pinhole in copper pipework, often from slow corrosion, can also drip steadily.
Less common but more serious is a cracked or corroded heat exchanger. If water is leaking from inside the boiler casing rather than from an external fitting, the heat exchanger may be failing. This is a major repair and, on older units, often signals it is time to consider replacement. A proper diagnosis tells you which category you are dealing with.
What NOT to Do
Do not keep topping up the system pressure to chase a leak. Repeatedly refilling a leaking boiler floods more water into your home and can mask a dangerous fault. If the pressure gauge keeps dropping after you refill, that is the leak talking and it needs a technician, not more water.
Do not run the boiler dry. Firing a boiler with low water can crack the heat exchanger and turn a minor seal leak into a four-figure repair. Leaving it off until help arrives is almost always the safer choice in our mild Vancouver climate, where a few hours without heat rarely causes pipes to freeze.
Do not attempt to tighten fittings or swap a relief valve yourself unless you are qualified. Boiler work in British Columbia is regulated, and the pressure relief valve in particular is a life-safety device. Improper repairs can void your warranty and create a hazard.
When to Call a Red Seal Gas Fitter
Call for professional help whenever the leak is coming from inside the boiler casing, when pressure will not hold, when the leak is more than a slow weep, or when you simply are not sure what you are looking at. A licensed technician can pinpoint whether you have a cheap fix like a worn pump gasket or a serious heat-exchanger problem.
GasBoilers.ca is a division of CanroHeat and we service boilers across Greater Vancouver, from Burnaby and Vancouver to the North Shore, Tri-Cities, Richmond, and Surrey. Our Red Seal gas fitters carry common parts on the truck so many leaks are repaired the same visit.
Most leak repairs fall into a wide range depending on the part and labour involved, from a modest valve or gasket replacement up to major component work. We will give you an honest assessment before any work begins. Call 604-359-1081 for an exact quote and fast service.