A gas boiler's circulator pump that never shuts off in a Coquitlam home usually points to a control fault, not a pump that needs replacing on its own.
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Quick answer
A circulator pump that runs continuously, even when no zone is calling for heat, is usually a control issue rather than a pump problem: a stuck relay on the control board, a thermostat or zone control wired incorrectly, or the pump's own control set to a continuous mode by mistake. A licensed tech checks the control signal to the pump before assuming the pump itself has failed.
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A circulator pump is told when to run by the boiler's control board, which is in turn triggered by a thermostat or zone valve calling for heat. When the pump runs non-stop regardless of whether anyone's asking for heat, the most common explanation is that the control signal telling it to stop isn't reaching it — a stuck relay on the control board, a wiring fault that's holding the circuit closed, or a setting on the pump itself left on a continuous or manual mode.
Some systems use the circulator for a secondary purpose too, such as domestic hot water priority or freeze protection, and a pump that appears to run constantly may actually be legitimately cycling for one of those functions rather than continuously heating the whole house — worth distinguishing before assuming a fault.
A pump that's genuinely stuck in the "on" position mechanically, rather than electrically, is less common but possible on an older unit, and shows up as a pump that keeps running even after the control board and wiring are confirmed to be sending a proper stop signal.
Because most causes trace to the control signal rather than the pump hardware, diagnosis usually starts at the control board and thermostat wiring, not by assuming the pump needs replacing.
Homes on Burke Mountain and in Partington with multi-zone systems have more wiring points where a fault could hold a call for heat active, simply because there are more zones and more thermostats involved. Older Maillardville and Austin Heights homes with simpler single-zone or two-zone systems have fewer points of failure, which can make the diagnosis quicker, though their control boards and relays are also older and more likely to be the actual source of a stuck relay.
A pump that's been running constantly through cold weather in a hillside home can also mask a legitimate issue — if that zone genuinely needs more run time to overcome a longer pipe run or a harder-to-heat room, it's worth ruling that out before assuming it's purely a control fault.
You can check whether any thermostat is stuck displaying a call for heat, and whether there's a mode switch on the pump itself set to "on" or "continuous" rather than automatic. A circulator pump running constantly does add to electricity use over time, though the boiler's burner itself only fires when there's an actual call for heat, so this isn't the same as continuous gas consumption.
A stuck relay or faulty wiring is a targeted electrical repair. A genuinely failed pump is a component swap. Neither points toward a new boiler — this is a control or component-level fix in the large majority of cases.
| Sign | Likely cause | Typical fix |
|---|---|---|
| Pump runs 24 hours regardless of thermostat setting | Stuck relay or control fault | Repair control board/wiring |
| Pump runs, mode switch set to continuous | Setting left in wrong mode | Reset to automatic |
| Pump runs constantly, mechanically stuck | Pump hardware failure | Replace pump |
Safety note
If you ever smell gas, hear a hissing sound near the boiler, or your carbon monoxide alarm sounds, leave the home immediately and call FortisBC at 1-800-663-9911 from outside before doing anything else. Do not attempt to relight a boiler or work on gas piping, venting, or combustion air yourself — that work must be done by a Technical Safety BC licensed gas fitter.
It's not an immediate safety issue, but it usually points to a control fault rather than intentional operation, and it does add unnecessary wear and electricity use over time, so it's worth having checked.
Not necessarily — the burner still only fires when there's an actual call for heat, so the pump running continuously doesn't automatically mean continuous gas use, though it should still be diagnosed.
Look for a mode switch on the pump itself that might be set to continuous or manual rather than automatic, and check whether any thermostat appears stuck calling for heat.
On some systems the pump legitimately cycles for domestic hot water priority or freeze protection, which can look like constant running but is a normal function — a tech can confirm which is happening.
They can be, simply because more zones and thermostats mean more wiring points where a fault could hold a call for heat active, though the root cause is still usually found and fixed directly.
Sometimes, but a stuck relay or wiring fault is more common than an actual pump failure, so a tech typically checks the control signal first before recommending a pump replacement.
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