Why Did My Energy Bill Go Up After Installing a Smart Thermostat?

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The thermostat itself isn't the culprit

A smart thermostat draws a tiny amount of power to run its screen and Wi-Fi connection, far too little to move your bill in any noticeable way. The energy your home uses comes from your furnace, heat pump, or air conditioner, and the thermostat only decides when those run. So when the bill jumps, the real question is: is the system now running more than it used to? Nine times out of ten the answer is yes, and it traces back to how the new thermostat was set up rather than a fault with the device.

Common reasons your bill went up

• A more comfortable schedule. Many people set the new thermostat warmer in winter or cooler in summer than the old dial actually delivered, so the system simply runs more.
• Setback features never got turned on. Auto-away, geofencing, and nighttime setback are what generate the savings. If they're off or misconfigured, you lose the benefit.
• Learning mode is still figuring you out. Some models spend the first couple of weeks learning your habits and may run more before they settle into an efficient pattern.
• The fan is set to 'On' instead of 'Auto'. Running the blower constantly uses electricity around the clock and can slightly raise heating and cooling costs.
• A wiring or C-wire issue is causing short-cycling. If the thermostat rapidly starts and stops the system, efficiency drops and wear increases.
• Colder weather or higher rates. It's worth checking whether the billing period simply covered a colder stretch or a rate change, not the thermostat at all.

What to check and adjust

Start by comparing your actual settings to how you used to run the house. Pull up the thermostat's schedule and confirm the temperatures and times match your routine. Then walk through these steps:

• Enable eco or setback periods for when you sleep and when the house is empty, and turn on auto-away or geofencing if your model supports it.
• Set the fan to 'Auto' so the blower only runs when there's heating or cooling to deliver.
• Check the energy report inside the thermostat app, which shows how many hours the system ran each day and can pinpoint an aggressive schedule.
• Give a learning thermostat two to three weeks before judging it, then review the schedule it created.
• Compare this bill to the same month last year rather than last month, since Metro Vancouver heating demand swings a lot between billing periods.

When to call a professional

If your system is short-cycling, if the thermostat keeps losing power or rebooting, or if the bill stays high after the schedule is dialed in, the issue may be a missing C-wire, a loose connection, or a compatibility mismatch with your equipment. Those are worth having checked, because a system that short-cycles wastes energy and puts extra strain on the furnace or heat pump. CANRO Heating & Cooling can verify the wiring, confirm the thermostat is compatible with your system, and make sure the setup is genuinely saving energy. Reach us at (604) 359-1081 or info@canroheat.ca for a diagnostic visit and a free written quote.

Frequently asked questions

Reviewed by the CANRO Heating & Cooling service team — July 07, 2026. Technical Safety BC gas licence LGA0043870 · boiler licence LBP0046450 · Red Seal certified · WorkSafeBC and liability insured · 4.9★ from 85+ Google reviews · serving Metro Vancouver since 1999 · (604) 359-1081.