Boiler Repair or Replacement? What Drives the Cost
“How much does a boiler cost?” is a fair question with an annoying answer: it depends. What we can do is explain what drives the price, so a quote makes sense when you get one.
Repairs: cheap, medium and expensive
Usually modest: bleeding air, a pressure relief valve, an expansion tank, a thermostat or zone valve, cleaning a condensate trap.
Middle: a circulator pump, an ignition electrode or flame sensor, a gas valve, a control board.
Expensive: a leaking or failed heat exchanger. On older boilers, this is usually where replacement starts to make more sense.
What affects the cost of a new boiler
- Boiler type: a heat-only boiler, or a combi that also makes domestic hot water.
- Size: based on the home’s heat loss, not the old boiler’s rating. Old cast-iron boilers were often oversized.
- Venting: switching from a chimney-vented boiler to a high-efficiency one means new PVC or polypropylene venting, and sometimes a chimney liner for the water heater left behind.
- Piping changes: condensing boilers work best with lower return water temperatures and often need primary/secondary piping, new pumps and an air separator.
- Water quality: old systems full of sludge need flushing and sometimes a dirt separator, or the new heat exchanger will clog.
When replacing makes sense
If the boiler is over 20 years old, needs a major part, or you’re already planning to replace the water heater, it’s worth looking at a combi or a high-efficiency boiler. Natural Resources Canada explains boiler efficiency ratings in its energy efficiency resources.
Estimates for new installations are free, and financing is available. See our boiler services or contact us at 647-657-2977. We work in Oshawa and the rest of the GTA.
