Gas vs electric tankless water heater
When shopping for a tankless water heater, the fuel choice, gas or electric, shapes everything from flow rate to installation to running cost. Both heat water on demand and save space compared to a tank, but they suit different homes.
For Metro Vancouver and Fraser Valley homeowners, the decision depends on your existing gas and electrical service, your hot-water demand, and local energy prices.
Here’s a clear comparison to help you weigh the options. HeatLand installs and services both gas and electric tankless units across the Lower Mainland and can assess which is realistic and cost-effective for your home.
Flow Rate and Whole-Home Capacity
The most important practical difference is capacity. Gas tankless units produce far more heat quickly, so they deliver higher flow rates, enough to run multiple showers or a shower and dishwasher at once in a typical home. That makes gas the usual choice for whole-home hot-water supply, especially in larger households.
Electric tankless units are limited by how much power the electrical service can deliver. A single high-capacity electric unit can serve a small home in a mild climate, but supplying a busy household with simultaneous demands often exceeds what’s practical, particularly when incoming water is cold in winter and more energy is needed to heat it.
Because our winter groundwater is cooler, the temperature rise required is greater, which reduces an electric unit’s effective flow more than in warmer regions. For high-demand whole-home use in the Lower Mainland, gas generally has the edge, while electric shines for smaller loads and point-of-use applications.
Installation, Venting, and Electrical Needs
Installation requirements differ significantly. A gas tankless unit needs a gas supply of adequate size and venting to expel combustion gases, which adds cost and requires a suitable route. It also needs a small amount of electricity for controls. These requirements make gas installation more involved but enable the high output.
An electric tankless unit needs no venting and no gas line, which simplifies placement and can lower installation complexity. The catch is electrical: whole-home electric tankless units draw a large amount of power and often require a dedicated high-amperage circuit and sometimes an electrical panel or service upgrade, which can be a significant added cost.
Which is cheaper to install depends entirely on what your home already has. A home with existing gas and venting may find gas straightforward, while a home needing a major panel upgrade for electric could see that cost dominate. A licensed assessment of your gas and electrical service is the only reliable way to compare real installation costs.
Running Cost, Efficiency, and Choosing
Operating cost depends on local energy prices and your usage. Electric tankless units are highly efficient at the point of use, converting nearly all their energy into hot water, while gas units lose some heat through exhaust, though high-efficiency condensing gas models narrow that gap considerably.
The cheaper fuel to run varies with electricity and gas rates, which change over time, so rather than quoting figures that may be outdated, the sensible approach is to compare current local rates for your expected usage. Both fuel types can also qualify for different rebates, and available programs and amounts change, so confirm current eligibility with the official program rather than assuming.
In short: gas typically suits whole-home, high-demand use where a gas line and venting exist or are feasible; electric suits smaller homes, condos, single fixtures, or supplemental point-of-use needs where venting is impractical. All installations involve gas or high-voltage electrical work and must be done by a licensed, insured, TSBC-certified technician. HeatLand can evaluate your service, demand, and budget and offers financing.
Quick Checklist
- Estimate your peak simultaneous hot-water demand
- Check your existing gas line size and venting options
- Verify electrical panel capacity for electric units
- Account for winter groundwater temperature
- Compare current local gas and electricity rates
- Confirm any rebate eligibility with official programs
| Factor | Gas Tankless | Electric Tankless |
|---|---|---|
| Flow rate | High, whole-home | Lower, best for small loads |
| Venting | Required | None |
| Electrical needs | Minimal (controls) | High-amperage circuit/upgrade |
| Upfront cost | Higher | Often lower (unit) |
| Best for | Larger, high-demand homes | Small homes, condos, point-of-use |
Frequently Asked Questions
Can an electric tankless water heater supply a whole house?
It can in smaller homes and milder climates, but our cooler winter groundwater requires a larger temperature rise, which reduces effective flow. Running multiple fixtures at once often exceeds what a single electric unit and the home’s electrical service can handle. For high-demand whole-home use, gas is usually more practical.
Does an electric tankless unit need an electrical upgrade?
Often, yes. Whole-home electric tankless units draw a large amount of power and typically need a dedicated high-amperage circuit, and sometimes a panel or service upgrade, which can be a significant cost. A licensed electrician or technician should assess your panel’s capacity before you commit to electric.
Which is cheaper to run, gas or electric?
It depends on current local gas and electricity rates and your usage, both of which change over time. Electric units are very efficient at the point of use, while high-efficiency condensing gas units are competitive. The best approach is to compare today’s rates for your expected demand rather than rely on general figures.
Do both types qualify for rebates?
Different rebate programs may apply to gas and electric tankless units, often tied to efficiency levels. Because program availability and amounts change over time, confirm current eligibility and figures with the official program rather than assuming. A licensed contractor can point you to the relevant programs when you get a quote.
Reviewed by the HeatLand Heating & Cooling team — licensed HVAC contractor serving Metro Vancouver & the Fraser Valley since 1999. This article is for general guidance only. If you smell gas, suspect a carbon monoxide leak, or are unsure about any electrical or gas component, stop troubleshooting immediately and call a licensed technician or 911.