Last reviewed: 2026-07-02 > Quick answer: At our Rice Lake shop, the median dedicated water pump job since 2023 billed about $210 in labour (roughly 2 hours) plus about $76 in pump parts, before HST (as of summer 2026, confirmed when you book); full kits with housing run...
Last reviewed: 2026-07-02
Quick answer: At our Rice Lake shop, the median dedicated water pump job since 2023 billed about $210 in labour (roughly 2 hours) plus about $76 in pump parts, before HST (as of summer 2026, confirmed when you book); full kits with housing run higher by model. It's the cooling system's only moving part and the cheapest insurance an outboard can buy. Book at hbw.wiki/service.
Our impeller post answered WHEN water pumps fail, with 766 jobs of evidence. The question people ask next at the counter is simpler: what does it cost to just do it?
Here are the real numbers from 112 dedicated water pump jobs since 2023, plus what's actually inside that bill and when "impeller" quietly becomes "impeller, kit, and thermostat."
Who this is for
Your impeller is on its interval, your telltale stream is weaker than last season, or an overheat alarm has you reading our overheating guide. Either way, you want the number before you book. If you're unsure whether it's due at all, the impeller timing post settles that first.
What the Job Actually Involves
The water pump lives at the top of your gearcase, driven by the driveshaft. Getting to it means:
- Drop the lower unit (bolts, shift linkage, driveshaft alignment)
- Remove the pump housing
- Replace the impeller, and in most cases the wear plate, gaskets, and O-rings around it
- Inspect the housing liner; replace if scored
- Reassemble, torque, and water-test
That's why the median job runs about 2 hours of labour. The impeller itself is a modest part; the labour of getting there is the job, which is also why doing it "while we're in there" during other gearcase work saves real money.
The Real Numbers
From our completed work orders (2023 to present, before HST; as of July 2026, confirmed when you book):
| Line |
Median at our counter |
Notes |
| Labour |
~$210 (about 2 hours) |
Drop lower unit, replace pump components, reassemble, test |
| Pump parts on the median job |
~$76 |
Impeller plus gaskets/wear items on the median job |
| Full pump kit with housing |
Higher, by model |
Quoted per motor when the liner is scored |
| Indicative all-in |
Labour + parts medians land near $300 |
Derived, before HST; V6/V8 and corroded hardware run higher |
What moves it up: a scored housing (full kit instead of impeller-and-plate), seized lower unit bolts on saltwater or neglected motors, a thermostat added while the cooling system is open, and any surprise the gearcase drain reveals while the unit is off.
What keeps it down: bundling. If your motor is already in for its annual winterize-and-service, the lower unit conversation is already half-done.
Impeller Only, or the Full Kit?
The honest version of the counter conversation:
- Impeller and wear plate is the standard job when the housing liner is smooth and the motor's been maintained on schedule.
- The full kit (housing or liner included) is the right call when the liner shows scoring, usually from an impeller that ran dry or disintegrated, or on motors past their second impeller interval.
- Fragments matter. If an old impeller went to pieces, the missing blades are somewhere in your cooling passages, and the job includes finding them. This is the expensive version of "I'll do it next year."
We put it on your file either way: what we found, what we installed, and when the next one's due.
Common mistakes
- Waiting for the failure. An impeller dies of heat in July, not politely in the driveway. The 766-job dataset shows midsummer is exactly when neglected pumps quit.
- Judging by the telltale alone. A strong stream is necessary, not sufficient; rubber ages on the calendar even when the stream looks fine. Interval beats vibes.
- Running dry "just for a second." A few seconds without water can take years off an impeller. Muffs on before the key, every time.
- Skipping the wear plate and gaskets to save a few dollars. The labour is the cost; reusing worn sealing parts against fresh rubber is how a two-year job becomes an annual one.
What HBW checks before your motor goes back on the water
Every pump job here ends the same way: reassembled to torque, run on water, telltale verified strong, and the interval noted on your file so the next one is planned instead of discovered. It's a small job done carefully, which is the entire point of it; 112 of them since 2023 and the come-backs are the motors we haven't met yet.
Frequently Asked Questions
How much does a Mercury water pump replacement cost in Ontario?
At our shop the median dedicated job since 2023 billed about $210 in labour (roughly 2 hours) plus about $76 in pump parts, before HST; a full kit with housing costs more and is quoted by model. Current rates are confirmed when you book at hbw.wiki/service.
How often should the water pump be serviced?
Follow your interval: for most Mercury outboards that's every 300 hours or 3 years for the pump service, with the impeller inspected sooner if the telltale weakens. Our maintenance intervals guide lays out the schedule.
Can I replace just the impeller and skip the kit?
When the housing liner is smooth and gaskets are healthy, impeller-and-wear-plate is the standard, honest job. Once the liner is scored or the motor has missed intervals, the kit is cheaper than doing the labour twice. We tell you which one your motor actually needs.
Is a weak telltale always the water pump?
No; the telltale outlet itself clogs with debris easily, and thermostat and poppet issues mimic pump problems. Our overheating at high speed guide walks the checks in order before anyone spends money.
Can I do the water pump myself?
Handy owners with a shop manual manage it, and the parts are affordable. The traps are shift-linkage alignment, driveshaft seal damage on reinstall, and torque on the housing. If any of that reads like a foreign language, two hours of shop labour is cheap tuition avoided.
When's the best time to book it?
Fall, bundled with your winterize-and-service while the shop's already working on the motor, or early spring before the rush. Mid-July, when everyone's pump fails at once, is the expensive time to need one.
Ready to Book the Pump?
Tell us the motor, the hours, and the last time anyone was in there.
Service requests: hbw.wiki/service
Questions? Text: 647-952-2153 or call: 905-342-2153
Address: 5369 Harris Boat Works Rd, Gores Landing, ON
Related guides:
Sources
- HBW service records, Rice Lake: 112 dedicated water pump jobs, 2023-2026 (medians before HST)
- Mercury Marine maintenance schedules (your owner's manual governs your model)
