Key Takeaways
- A power vent water heater uses a fan to push exhaust out a side wall, so no chimney is needed.
- They're common when a high-efficiency furnace leaves an old water heater without a safe chimney.
- They need electricity to run, so they won't heat water during a power outage.
- Vent terminals must be kept clear of snow and ice through Ottawa winters.
If you've recently upgraded your furnace, finished your basement or been told your chimney isn't suitable for venting anymore, you may hear the term power vent water heater. It's one of the most common types of gas water heaters in Ottawa homes, and for good reason: it solves a venting problem that a lot of older houses run into.
This guide explains how a power vent water heater works, when it's the right choice, what to watch out for, and how to keep it running reliably through an Ottawa winter.
What Is a Power Vent Water Heater?
A power vent water heater is a gas-fired tank heater with an electric fan (blower) mounted on top. Instead of relying on hot exhaust to rise naturally up a chimney, the fan pushes combustion gases out through plastic vent pipe, usually to a side wall of the house.
By comparison, a conventional or "atmospheric" water heater has no fan. Its exhaust rises through a metal vent connector into a chimney, using natural draft.
How it works, step by step
- The thermostat calls for heat when the water in the tank cools down.
- The blower starts and confirms proper airflow with a pressure switch.
- The gas burner lights and heats the water.
- The fan pushes exhaust out through the vent pipe to the outdoors.
- When the tank reaches temperature, the burner shuts off and the fan stops after a short purge.
When Do You Need a Power Vent Water Heater?
Many Ottawa homeowners end up with a power vent model for one of these reasons.
You upgraded to a high-efficiency furnace
Older homes often had the furnace and water heater sharing one chimney. When the furnace is replaced with a high-efficiency model that vents through PVC pipe, the water heater is left alone in a chimney that is now too large for it. That can lead to poor draft, condensation and even exhaust spilling back into the home. Switching to a power vent water heater is a common, safe solution.
Your chimney is damaged or being removed
Masonry chimneys in older neighbourhoods like Westboro, Alta Vista and parts of Nepean can deteriorate after decades of Ottawa freeze-thaw cycles. If repairing or lining the chimney isn't practical, a power vent model lets you stop using it for the water heater.
You're moving the water heater
Finishing a basement or reorganizing a utility room sometimes means the water heater can't stay next to the chimney. A power vent model can be located more flexibly, as long as the vent run and clearances meet code.
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Pros and Cons to Consider
| Pros | Cons |
|---|---|
| No chimney needed — vents through a side wall | Needs electricity; no hot water during a power outage |
| More flexible placement in the home | The fan adds some noise when running |
| Reduces the risk of exhaust spilling back into the home | More components (fan, pressure switch) that can fail |
| Often more efficient than an atmospheric tank | Typically costs more upfront than a conventional tank |
For many homes, the safety and flexibility outweigh the downsides. If you'd rather avoid a tank altogether, a tankless unit is another option that vents through a side wall — we can explain both during a site visit.
Common Power Vent Water Heater Problems
Because a power vent water heater relies on a fan and safety switches, it has a few more things that can go wrong than a basic tank. Common issues include:
- No hot water after a power outage: The unit may need to be reset once power returns.
- Blocked vent terminal: Snow, ice, leaves or even nesting birds can block the outside vent. The pressure switch then stops the burner from lighting as a safety measure.
- Pressure switch faults: A failed switch or a cracked or water-filled sensing tube can prevent the burner from firing.
- Blower motor wear: Louder-than-usual humming, rattling or squealing can mean the fan is wearing out.
- Error codes or flashing lights: Many models flash a code to show what's wrong. Write it down before calling for service.
The Ottawa winter factor
Side-wall vents are close to the ground, and Ottawa winters regularly bring heavy snow, drifting and temperatures below −25 °C. A vent buried by a snowbank or frozen over by ice can shut your water heater down. After big storms, check that the intake and exhaust terminals outside are clear — and never pile snow against them when shovelling.
If you ever smell gas, leave the home immediately and call the Enbridge Gas emergency line or 911 from outside. If a carbon monoxide alarm sounds, get everyone out and call 911.
Getting the Installation Right
Installing a power vent water heater involves gas piping, venting, electrical and water connections. In Ontario, the gas work must be done by a TSSA-licensed gas technician — this isn't a DIY job.
A proper installation includes:
- Choosing the right tank size for your household's hot water needs.
- Planning the vent route within the manufacturer's maximum length and number of elbows.
- Locating the vent terminal with correct clearances from windows, doors, decks, the gas meter and grade.
- Making sure there's a dedicated electrical outlet nearby.
- Testing for gas leaks, verifying draft and checking safe operation before we leave.
Costs vary with the tank size, the length and complexity of the vent run, and any gas or electrical changes needed. With KAD, you get upfront pricing and no hidden fees. Learn more about our furnace and water heater installation services, or request a free quote.
Owned or rented?
Many power vent water heaters in Ottawa are rentals. If yours is rented and having problems, check your agreement first. If you're thinking about owning your next water heater, we can walk you through what's involved.
Maintenance Tips for Reliable Hot Water
Regular maintenance helps your power vent water heater last longer and work more efficiently, which can help keep your Enbridge Gas bill in check. A maintenance visit typically includes:
- Flushing sediment from the bottom of the tank.
- Inspecting the blower, pressure switch and sensing tubes.
- Checking the vent pipe and terminals for damage or blockage.
- Testing the temperature and pressure relief valve.
- Inspecting the anode rod and gas connections.
Our furnace and water heater maintenance service can take care of both appliances in one visit — ideally in the fall, before the coldest weather arrives.
Power Vent Water Heater Service Across Ottawa
KAD Mechanical & HVAC has been serving Ottawa for over 10 years, with more than 500 completed projects and 98% customer satisfaction. Our certified, TSSA-licensed technicians install, repair and maintain power vent water heaters throughout Ottawa, Kanata, Nepean, Barrhaven, Orleans and nearby communities. If your water heater stops working or is due for replacement, explore our water heater installation options or book a repair visit.
Talk to a Certified Technician Today
Call (613) 790-2675 or request your free quote online — we respond fast.
Questions about a power vent water heater? Call (613) 790-2675 or book online and we'll help you find the right solution for your home.
Frequently Asked Questions
Does a power vent water heater work during a power outage?
No. The blower needs electricity, so the burner won't fire without power. Any hot water already in the tank stays usable for a while, and the heater will usually restart once power returns.
Why did my water heater need to become a power vent model when I replaced my furnace?
A high-efficiency furnace vents through PVC pipe, which can leave the water heater alone in a chimney that's too large for it. That can cause poor draft and exhaust spillage, so a power vent water heater is often the safest fix.
Why is my power vent water heater not lighting?
Common causes are a blocked outside vent (often snow or ice in winter), a faulty pressure switch, a worn blower or a power interruption. Check that the vent terminal is clear, then call a licensed technician.
Is a power vent water heater noisy?
You'll hear a fan running while the burner is on, which is normal. Loud rattling, squealing or grinding usually points to a worn blower motor that should be inspected.
Certified, TSSA-licensed heating, water heater and gas technicians serving Ottawa, Kanata, Nepean, Barrhaven and Orleans for 10+ years.
Next article: Tankless vs Tank Water Heater: Which Is Better for Your Ottawa Home?
