6. Mechanics of Buying, Installing or Upgrading

6. The Mechanics of Buying, Installing or Upgrading a System

Buying Your Equipment

You cannot shop for a furnace the way you shop for a camera or a pair of shoes. There are not many "furnace stores" where makes and models can be examined, compared and priced. To get first-hand information on the different makes and models available, you will have to contact a number of heating firms. Ask them for the manufacturers' illustrated sales literature on the furnaces they sell and install. You should also contact your local gas utility or a local contractor for assistance and information. Your utility can usually provide information on the cost of purchasing, renting or installing furnaces and the estimated seasonal heating costs of the type of equipment you plan to use.

If you have decided on a particular type of furnace, read the literature carefully to find out if it describes the features you are looking for – such as a condensing heat exchanger and a high-efficiency brushless DC motor for the circulating fan. Also, look for the EnerGuide rating. This is the seasonal efficiency (AFUE) rating, not just the steady-state efficiency. Make sure you distinguish between the two types of ratings. For more information on the EnerGuide rating system for gas and propane furnaces, refer to page 16.

Ask your contractor to calculate the heating requirement of your house. The furnace size should preferably be determined by a heat loss calculation using the method prescribed in CSA F280, "Determining the Required Capacity of Residential Space Heating and Cooling Appliances." This method requires a thorough measurement and examination of your house to determine size, insulation levels and the degree to which the house envelope is airtight. Alternatively, the contractor may arrive at a reasonably good estimate using calculations based on the fuel consumption history of your present furnace over a known period, and the known climatic history for your location over the same period.

Before settling on the size of furnace, you should ask the contractor to provide you with the calculation results, including a summary of the general design assumptions, and a statement of the calculation method(s) used. A calculation based simply on the floor area of the home, or on replacing the furnace with one of "equivalent" size, is not adequate in most cases. If the contractor does not show any interest in either a detailed assessment of the house or a review of your past heating bills, then his or her calculation of your furnace size is likely to be not much more than a "guesstimate."

It is important to hire a contractor who will install your equipment properly to ensure that it will operate efficiently. Check with your local gas utility or provincial/territorial gas regulatory office to find out how to get in touch with a fully qualified, registered or licensed contractor. If your neighbours have had similar work done recently, ask them how satisfied they were with their contractor.

Before you decide what to buy, obtain firm, written bids from several companies on the cost of buying and installing a complete new unit, along with any other fittings and adjustments required, including changes to any ductwork or piping and a final balancing of the heat supply to the house.


Before replacing your heating system, you should consider having a home energy audit carried out by a qualified EnerGuide for Houses advisor. The advisor will provide you with a thorough whole-house energy evaluation and analysis, including

  • a guided tour of your house to point out areas of air leakage
  • an easy-to-understand report on your home's energy performance
  • a home improvement plan that will show you how to lower your energy costs
  • an EnerGuide for Houses rating and label so you can compare your home with others across Canada

By following up on the recommendations of such an audit, you may be able to reduce the size of furnace required. For more information on EnerGuide for Houses, see page 69.


You should get several estimates on the work to be done. When you are comparing these estimates, cost will be an important factor, but there are other considerations involved. Some contractors may be better at explaining what has to be done. Some may use higher-quality components, and others may schedule the work at your convenience.

Estimates should include the following items:

  • the total cost for all necessary work
  • an itemized list of all material and labour costs in the bid, including those for the
    • alteration or improvement of existing heat distribution ducts
    • installation of furnace and gas supply piping and ductwork
    • installation of water heater and vent (where applicable)
    • installation of chimney liner and any attendant masonry work
    • installation of additional equipment, such as gas appliances, humidifiers, air cleaners or air conditioners
  • a statement describing how much existing equipment will be used in the new system
  • a rough diagram showing the layout of ductwork or water pipes and the location of supply piping and heating equipment
  • a statement that clearly defines who is responsible for
    • all necessary permits and payment of related fees
    • on-site inspections by the utility
    • scheduling of all other required work by the utility, such as supply pipe installation and hookup
    • removal of any existing equipment that will not be used with the new system
    • all related costs, such as subcontracts with tradespeople
  • a clear estimate of when the work will be completed
  • a warranty for materials and labour
  • a schedule and method of payment

Ask contractors for the names of homeowners for whom they have done similar work. The Better Business Bureau will know if the contractor is a member and whether any recent complaints have been filed against him or her. Your local Chamber of Commerce or Board of Trade may also be able to provide information.

The contractor installing the heating system may be able to install additional gas-fired appliances for a favourable price at the same time as the heating system is set up. This work can often be undertaken without duplication of the inspections, permits and labour associated with such jobs.

Some utilities or dealers will also offer rental of heating equipment or lease-to-purchase plans. You may find it advantageous to participate in one of these plans rather than to purchase the equipment outright.

Do not hesitate to ask the contractor for a clear explanation of any aspect of the work before, during or after the installation of your heating system.


Billing for natural gas service is handled in different ways, with two of the most common ones being equal billing and standard billing.

Equal billing. Your gas bill is paid in regular, equal instalments, based on an estimate of your annual total consumption. Periodic adjustments are made to balance your monthly charge against your actual yearly household consumption.

Standard billing. Gas utility bills are paid on a monthly basis for gas consumed during that month. Your gas meter is read periodically and bills are adjusted accordingly.

There may be a minimum monthly charge for natural gas service, and a small monthly payment may be required in the summer months even if gas is not used. This will not be a noticeable factor in homes equipped with gas water heaters or other gas appliances. In some areas, there is an extra fixed administrative charge in addition to the minimum monthly billing.

To determine your actual gas cost, you may have to calculate the sum of the charge for distribution and the charge for gas itself.

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Source: Natural Resources Canada (NRCan) - Office of Energy Efficiency