Thermostats in Smithville, ON — Check the Wiring Before You Buy One

The box on your wall is probably older than the furnace behind it. Most people only think about it when they want a schedule, or when somebody mentions the rebate. One question comes before either of those: will a smart thermostat work with the wiring already in your Smithville house? This page answers that first, then covers the $100 Ontario pays toward one, and the second programme that pays again afterwards.

What Decides Whether a Smart Thermostat Will Work in Your House

Usually it will work, and the wiring behind the plate decides it.

Most smart models want a C-wire, a fifth wire carrying constant power rather than only a switching signal. Houses wired before smart thermostats existed often have four wires and no fifth.

• Take the cover off and count the wires. Four is common here, five makes the job simple.
• Batteries and adapters close most of the gap. Not every model, and not every house.
• Ontario’s rebate programme says so in its own words. Check the compatibility information before you buy. (2)

The Wire Behind the Plate

An old thermostat is a switch. It closes a contact, the furnace or the air conditioner runs, and the thermostat needs no power of its own to do that.

A smart one is a small computer on your wall. It stays awake, holds a Wi-Fi connection and lights a screen, so it needs a live supply of its own.

That supply is the C-wire, short for common wire, and it runs back to the equipment the thermostat controls. Plenty of Smithville houses were wired for a thermostat that was only ever a switch, so the plate has four wires on it and nobody ever missed the fifth.

Three things follow from that. Some models run on batteries and sidestep the problem entirely. Some ship with an adapter that lets a spare wire carry the power instead. Some houses need a new wire pulled from the furnace or air handler, which is a job rather than a purchase.

Count the wires before you shop. If the system is already misbehaving, the plate may not be where the trouble sits. Two other places are worth a look: the other end of those wires, when the heat does not come on, and when the trouble turns out to be the air conditioner, not the thermostat.

Ontario Pays $100, and There Are Two Ways to Take It

Ontario’s Home Renovation Savings programme pays $100 toward a smart thermostat, and you choose when to take it. (4)

Ask for a code before you shop, and the $100 comes off at the till. Buy the thermostat first instead, and you upload the receipt afterwards. (4) That second route carries a deadline of sixty days from the purchase date, and the deadline is the part people miss. (4)

Two kinds of household qualify: an Enbridge Gas customer who heats with a gas furnace or boiler, or a house on the Ontario electricity grid that heats or cools electrically. (2)

One condition catches people out. The rebate runs once per household, ever. If somebody at your address has already taken a smart thermostat rebate, discount or free device from Enbridge Gas, Save on Energy or this programme, your household has used it. (2)

Six makes sit on the eligible list: ecobee, Google Nest, Honeywell Home, Copeland Sensi, Mysa and Sinopé. (2) Ecobee is designed in Toronto, which is worth knowing if you would rather buy closer to home.

Peak Perks Pays Again, and What You Agree To

A second Ontario programme pays you for having the thermostat rather than for buying it. Save on Energy runs Peak Perks, and it pays $75 when you enrol and $20 for each year you stay in. (3)

The agreement matters as much as the money, so read it first. On the days when Ontario’s grid is under the most strain, the programme adjusts your thermostat for you, and the adjustment is capped at two degrees Celsius and at three hours. (3)

You are told before every adjustment, and you can leave at any time by changing the temperature yourself or through the app. (3)

Eligibility is narrower than the rebate. The programme wants a residential Ontario electricity customer with central air conditioning controlled by that thermostat, and a heat pump counts where it forms part of central air conditioning. (3) Read that rule against your own system first, because ductless systems and the controls that come with them do not always work the same way.

What to Set It To

Space heating and cooling accounts for almost two thirds of what a Canadian home spends its energy on. (1) That share is why moving the setpoint is worth more than most other changes you can make for nothing.

Natural Resources Canada gives a starting schedule: 17°C while you are asleep or out of the house, and 20°C while you are awake and at home. (1) The saving comes from the gap between those two settings, and two to three degrees is the drop that same guidance calls optimal. (1)

A schedule changes when the system runs. It does not change what the system can do, so no thermostat will rescue equipment that is undersized or overdue a service.

Winter and summer also want different schedules from the same box. Set one in October and forget it, and the cooling side spends July running on a plan written for January.

Frequently Asked Questions

Can I install a smart thermostat myself? Many people do, and the wiring at the wall is low-voltage rather than mains. Label every wire before the old plate comes off, because the terminals are not always marked the same way from one brand to the next. The real risk sits at the far end, on the control board inside the furnace or air handler, where one wire on the wrong terminal costs more than the thermostat did.

Can I get a free smart thermostat in Ontario? Not free, but $100 off, which covers a good share of an entry-level model. (4) Take it as a code at the till, or upload your receipt within sixty days of buying. (4)

Which smart thermostats qualify for the Ontario rebate? Six makes are on the programme’s eligible list: ecobee, Google Nest, Honeywell Home, Copeland Sensi, Mysa and Sinopé. (2) The list works by model rather than by brand, so check your specific model against it before you pay.

Does a new furnace or air conditioner need a new thermostat? Not always. A two-stage furnace or a heat pump asks more of a thermostat than a single-stage system did, so the answer turns on what your existing one can drive. Anyone quoting the job should tell you which way yours falls before the order goes in.

Before You Buy Anything

Take the cover off the thermostat, count the wires, and phone the office with that number. One figure tells us most of what we need to know about whether your swap is simple or a wire has to be pulled. We cover the rest of it from a service call to a new system. Our technicians carry the 313A certificate Ontario requires for this trade, in a family business running since 2014.

References

1. Natural Resources Canada, Smart Thermostats, natural-resources.canada.ca
2. Home Renovation Savings, Smart thermostat rebate, homerenovationsavings.ca
3. Save on Energy, Peak Perks, saveonenergy.ca
4. Home Renovation Savings, Terms & Conditions — Smart Thermostat, Before you buy and After you buy (version January 2026), homerenovationsavings.ca