How-to · 10 minutes · easy

How to Read Your Hydro Bill for HVAC Waste

Your gas and hydro bills are an HVAC efficiency report card. Reading them year-over-year shows whether the system is degrading. Here's how.

What you'll need

Steps

1

Pull 13 months of bills

Most utilities have an online portal. Download the past 13 months — covers a full heating + cooling cycle plus a baseline.
2

Build a simple spreadsheet

Columns: month, m³ gas used, kWh used, $ total. Add a column for heating-degree days (HDD) — search the month + 'Toronto HDD' to find historical data.
3

Calculate gas use per HDD

Divide each month's gas use by HDD. Healthy efficient furnace: 0.10–0.13 m³/HDD. If yours is 0.18+/HDD, the furnace or duct system is wasting fuel.
4

Calculate AC kWh per cooling-degree day

Same idea for summer. Healthy AC: 5–8 kWh/CDD for a typical 2,000 sq ft home. Higher = old or undersized.
5

Compare year-over-year

Same month last year vs this year (controlled for HDD/CDD). 15%+ jump signals real degradation.
6

Spot anomalies

Late-summer gas spike = water heater. Mid-winter electric spike = heat-pump backup running too much. Track these patterns.

When to stop and call

If your gas-per-HDD is over 0.18 or has jumped 20% year-over-year with no lifestyle change, it's a tune-up call at minimum. (416) 258-2460.

Open 24/7

Most GTA calls get same-day service. Call, text, or request a fixed quote — we'll come back with a real ETA.

Mississauga, ON · Greater Toronto Area and up to 2 hours out — London, Kitchener, Barrie, Kingston, Niagara.