Why Lochinvar Boilers Leak
Lochinvar is widely used across Greater Vancouver in both residential and light-commercial settings, with the Knight series among the most familiar condensing models. As a modern high-efficiency boiler, a Lochinvar produces acidic condensate and runs cool return temperatures, so its leaks tend to follow the same predictable pattern as other condensing units.
The usual sources are the condensate trap and drain line, the pressure relief valve, circulator pump and union fittings, and the O-rings and gaskets within the hydronic assembly. Because these boilers are compactly built, a small weep from one fitting can run down the chassis and collect at the base, making the visible pooling a poor guide to the actual source.
A genuine heat-exchanger leak is less common but does occur on units with poor water chemistry or a history of low-pressure running. The diagnosis always begins by tracing the water to its true origin.
Condensate and Relief Valve Leaks
The condensate trap on a Lochinvar collects the acidic water created as flue gases cool and condense. If the trap cracks, its seal fails, or the drain line clogs with sediment or biofilm, condensate backs up and leaks from the bottom of the boiler. This is one of the most routine Lochinvar leak repairs and usually involves cleaning or replacing the trap and clearing the drain.
The pressure relief valve is the other common source. Water at the valve or its discharge pipe means system pressure has exceeded the safe limit. On Lochinvar systems this frequently traces back to a waterlogged or undersized expansion tank rather than a defective valve, so a thorough technician checks the expansion tank and overall pressure before deciding whether the valve itself needs replacing.
Both repairs are straightforward when done with the correct parts and followed by proper re-commissioning of the boiler.
Heat Exchanger and Internal Leaks
If water appears to be leaking from inside the sealed combustion area rather than from an accessible fitting, the heat exchanger or an internal seal may be at fault. Lochinvar condensing boilers use durable heat exchangers, but poor system water quality, trapped air, or repeated low-pressure operation can shorten their life.
Warning signs of an internal leak include steady pressure loss with no visible external drip, white mineral staining inside the casing, and corrosion around the heat exchanger. These are not DIY repairs, as they require opening a sealed combustion unit and working to manufacturer procedures.
On an older Lochinvar, a heat-exchanger leak becomes a repair-versus-replace decision. Our technicians will give you an honest assessment of the cost either way and help you check whether a high-efficiency replacement would qualify for current FortisBC rebates.
Lochinvar Repair Across Greater Vancouver
GasBoilers.ca, a division of CanroHeat, services Lochinvar boilers, including the Knight series, throughout Burnaby, Vancouver, the North Shore, the Tri-Cities, Richmond, and Surrey. Our Red Seal gas fitters work on Lochinvar equipment in homes and small commercial buildings and re-commission every repair properly.
Many Lochinvar leaks, such as the condensate trap, relief valve, and pump gaskets, are resolved the same visit once the cause is confirmed. Accurate diagnosis matters, because an external fitting leak and a heat-exchanger leak are at opposite ends of the cost scale.
Minor Lochinvar leak repairs fall at the lower end of the cost range, while heat-exchanger work sits much higher. We always diagnose and quote before any work begins. Call 604-359-1081 for an exact quote on your Lochinvar boiler.