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Boilers · MaintenanceBoiler Tune-Up & Annual Service
A boiler tune-up and annual service is a once-a-year visit in which a TSSA-licensed gas technician measures combustion, cleans the burner and heat exchanger, and tests the water side: pressure, expansion tank, relief valve, air elimination and circulators. Book it every year, ideally in September or early October before the heating season. Condensing boilers need it most, because their heat exchangers foul on the fire side and their condensate traps clog.
Boiler service in Burlington, Oakville and Hamilton covers two very different machines. The cast-iron atmospheric boilers in pre-war brick houses are simple and forgiving, and their service is about burners, draft and the hydronic parts around them. The wall-hung condensing boilers that replace them are efficient and exacting: a fan, a sealed burner, a stainless or aluminum heat exchanger and a control board that locks out when a reading drifts. The visit is built around whichever one is in your basement.
The fire side comes first. A combustion analyzer in the flue records oxygen, carbon monoxide and flue temperature, and on a condensing boiler the gas valve is adjusted to the manufacturer's combustion figures at both high and low fire. The burner is removed and cleaned, the igniter and flame sensor are checked, and the heat exchanger's fire side is brushed and rinsed of the gritty deposits condensing boilers build up. Those deposits wash down into the condensate trap, so the trap is taken apart and flushed and any neutralizer is checked.
The water side gets the same attention. Cold fill pressure is confirmed, usually 12–15 psi; the expansion tank is isolated and its pre-charge measured; the relief valve and its discharge pipe are inspected; air separators and automatic vents are checked; and each circulator and zone valve is run on a call for heat. Systems with antifreeze, such as a garage or snow-melt loop, have the glycol tested. A tank found waterlogged is flagged for expansion tank replacement before it starts tripping the relief valve in January.
Safety controls are tested, not just looked at. The low-water cut-off is proven to stop the burner, the flame safeguard is checked by removing the flame signal and confirming the gas valve closes, and the high-limit aquastat, the pressure switch and, on atmospheric boilers, the spill switch are verified. This page is maintenance only: faults and replacements belong to boiler repair, and forced-air systems are covered by the furnace tune-up.
What a boiler tune-up includes
- Combustion analysis with oxygen, CO and flue temperature recorded on the invoice
- Burner, igniter and flame sensor cleaned; the fire side of a condensing heat exchanger brushed and flushed
- Condensate trap and drain cleared, venting and air intake inspected end to end
- System pressure, expansion-tank pre-charge, relief valve, air vents, circulators and zone valves checked
- Low-water cut-off, flame safeguard and high limit tested, and the home's carbon monoxide alarms confirmed working
How it works
Call in late summer with the boiler's make, model and age. Condensing boilers often need a gasket or igniter kit at service, and knowing the model lets us bring it.
Expect the boiler to be off for the visit while the burner is out. The technician works through the fire side, the water side and the safety controls, recording each reading.
You receive the combustion numbers, the pressures and a short list: fine, watch, or fix. Request a service date and we will confirm the price for your boiler.
Brands: We service residential cast-iron, condensing and combi boilers of all major makes, including Navien, IBC, NTI, Viessmann and Weil-McLain.
Common questions
How often does a boiler need servicing?
Once a year. Condensing boiler manufacturers specify annual service in their manuals, and warranty claims can depend on records of it. A cast-iron boiler tolerates neglect better but still has a relief valve, an expansion tank and a flue that should be checked yearly, since those are the parts that fail quietly.
What happens if a condensing boiler is not cleaned?
Combustion deposits coat the heat exchanger, flue temperature climbs and efficiency drops. The same debris fills the condensate trap; when condensate backs up into the heat exchanger the boiler locks out on an ignition or pressure fault, typically during the first hard cold spell when it runs longest. Cleaning is routine at one year and a much bigger job at five.
Does a combi boiler need anything extra?
Yes: the hot-water side. Halton and Hamilton water is hard, and scale builds in the plate heat exchanger that makes domestic hot water, showing up as shower temperature that swings. Service includes checking that exchanger and flushing it with descaling solution where needed. Repairs beyond that are on our combi boiler repair page.
Is boiler service different from a furnace tune-up?
The combustion test is similar; almost everything else differs. A furnace visit deals with airflow, filters and a blower. A boiler visit deals with water: pressure, air in the system, the expansion tank, circulators and the relief valve. A technician who services only furnaces will miss the hydronic half, which is where most boiler breakdowns start.
Should the system water be flushed every year?
No. Draining and refilling brings in fresh oxygenated water, which is what corrodes a hydronic system. The water is inspected at service, and a flush is recommended only when it is black with sludge, radiators have cold bottoms or a new boiler is going onto old piping — see hydronic system flush.