Furnaces, boilers, water heaters, tanks and lines for the houses with no gas main: propane, and oil where the tank is still in the basement. Burner and fuel line work requires a TSSA fuels certificate, and an oil tank has to satisfy the fuel distributor's inspection before they will keep filling it.
Quote only
A propane furnace or boiler supplied and installed. A conversion from oil sits at the high end. Excludes the tank, the regulator and the line, which are often rented from the fuel supplier under a contract, and excludes removing an oil tank.
Demand and price peak in fall. Booking outside it is the cheapest saving available on this job.
Required by law. Ontario law requires this credential for the work. A contractor without it cannot legally do the job, whatever the quote says. Technical Standards and Safety Act, 2000, O. Reg. 215/01 (Fuel Industry Certificates).
You asked for the trade Propane and oil heating, and the words "remove popcorn ceiling", and businesses serving Markham. Of the 12 businesses listed, none match every one of those.
The cost band and the licence requirements above still apply. They are what you need to judge a quote from anywhere else: whether the price is in the range, and whether the person quoting is allowed to do the work at all.
Dropping any single one of those filters still leaves nothing, so it is the combination rather than one filter.
Listings here are seed data for demonstration and are labelled as such on each profile. Cost bands are what GTA homeowners are typically quoted, not offers. Always confirm a licence number against the issuing registry yourself before work starts.