Can Tankless Water Heater and Furnace Share Vent: Safety, Efficiency, and Benefits Explained

Can Tankless Water Heater and Furnace Share Vent?

Yes, a tankless water heater and furnace can share a vent, but it is important to choose compatible systems to avoid hazards.

Running both systems simultaneously may require a larger vent pipe to accommodate the exhaust.

Tankless water heaters can be power vented or directly vented, with direct venting being suitable for smaller spaces.

Some tankless water heaters have all-in-one concentric vents, eliminating the need for distancing from walls and containing warm air within the pipe.

Outdoor tankless water heaters do not require additional ventilation and can tolerate subzero temperatures.

It is recommended to consult professionals to ensure proper configuration when sharing a vent and to avoid hazards.

High-efficiency furnaces require separate venting, necessitating the replacement of the existing vent pipe for the water heater.

Incorrect water heater venting can lead to backdrafting, exposing occupants to carbon monoxide and potential health hazards.

Proper water heater venting can be tested by reducing the furnace thermostat, running the water heater, and visually detecting backdrafting using an incense stick.

Key Points:

  • Tankless water heaters can share a vent with a furnace, but compatible systems must be chosen to prevent hazards.
  • Larger vent pipes may be needed to accommodate the exhaust when running both systems simultaneously.
  • Tankless water heaters can be power vented or directly vented, with direct venting suitable for smaller spaces.
  • Some tankless water heaters have all-in-one concentric vents that eliminate the need for distancing from walls and contain warm air within the pipe.
  • Outdoor tankless water heaters do not require additional ventilation and can tolerate subzero temperatures.
  • Consult professionals to ensure proper configuration when sharing a vent and to avoid hazards.

Did You Know?

1. Contrary to popular belief, tankless water heaters and furnaces cannot share the same vent due to differences in exhaust temperature.
2. Tankless water heaters are more energy-efficient than traditional water heaters, as they only heat water on demand, saving up to 30% of energy costs.
3. Furnaces typically require larger-diameter vents compared to tankless water heaters, which can limit the space available for a shared venting system.
4. Shared venting between a furnace and tankless water heater can cause condensation buildup, resulting in damage to both appliances.
5. While it may seem like a cost-effective solution, attempting to share a vent between a tankless water heater and furnace can lead to premature equipment failure and potential safety hazards.

Related Post:  How to Remove Faucet Handle Without Screws: Easy Solutions!

Energy Efficiency and Reduced Emissions

Tankless water heaters have gained popularity due to their energy efficiency and reduced greenhouse gas emissions. Traditional storage tank water heaters constantly heat and store water, resulting in wasted energy and higher utility bills. In contrast, tankless water heaters only heat water when needed, leading to significant energy savings. This energy efficiency not only benefits homeowners financially but also reduces the overall carbon footprint, contributing to a greener and more sustainable environment.

Importance of Proper Ventilation

Proper ventilation is crucial when it comes to tankless water heaters. Ventilation serves two primary purposes: ensuring the safety of occupants and maximizing the efficiency of the water heater. Without adequate ventilation, harmful gases such as carbon monoxide can accumulate inside the house, posing serious health risks. Additionally, proper ventilation allows for the efficient removal of combustion byproducts, allowing the tankless water heater to operate optimally.

Compatibility and Hazards

While it is possible for tankless water heaters and furnaces to share a vent, caution must be exercised to avoid compatibility issues and potential hazards. Ensuring compatibility between the two systems is vital, as mismatched systems can lead to improper venting and potential safety risks. It is advisable to consult professionals who can assess the compatibility of the existing vent system and make necessary adjustments.

Larger Vent Pipe

When running both a tankless water heater and a furnace simultaneously, it may be necessary to install a larger vent pipe in order to accommodate the increased exhaust volume.

This larger vent pipe allows for the proper removal of byproducts from combustion, preventing potential blockages and ensuring the efficiency of both systems.

  • Installing a larger vent pipe is crucial for handling increased exhaust volume.
  • Proper removal of combustion byproducts is essential for system efficiency.
  • Prevents potential blockages and ensures optimal performance.

5. Venting Options

Tankless water heaters offer two primary venting options: power venting and direct venting.

  • Power venting involves using a fan or blower to push the exhaust gases out of the house. This method is suitable for situations where venting through the side wall is not feasible due to space constraints.
  • Direct venting, on the other hand, utilizes a concentric pipe that separately vents the combustion air and exhaust gases. Direct venting is ideal for smaller spaces as it requires less clearance and contains the warm air within the pipe, maximizing energy efficiency.
Related Post:  What Does a Water Softener Do and Why is it Important for Your Home?

All-In-One Concentric Vents

Some tankless water heaters feature all-in-one concentric vents, eliminating the need for additional distancing from walls and maintaining the heat within the pipe. These compact vents are designed to be more space-efficient and simplify the venting process. Homeowners should consider opting for tankless water heaters with all-in-one concentric vents to streamline installation and maximize efficiency.

In conclusion, the shared venting of a tankless water heater and furnace is possible, but it is crucial to ensure compatibility and consult professionals to prevent hazards. Choosing the right venting options, such as larger vent pipes and all-in-one concentric vents, can enhance safety, efficiency, and overall performance. Homeowners should prioritize proper ventilation to promote energy efficiency, reduce emissions, and maintain a safe and comfortable living environment.


Check this out:


Frequently Asked Questions

Can water heater and furnace use same exhaust pipe?

Yes, it is possible for a water heater and furnace to share the same exhaust pipe, especially in homes with standard efficiency furnaces. This is a common practice, and when properly installed, it effectively vents the combustion gases generated by an 80% (or less) gas furnace and a gas water heater. The shared venting arrangement allows for efficient and cost-effective operation of both appliances while ensuring the safe expulsion of exhaust gases.

Is my tankless water heater connected to my furnace?

No, your tankless water heater is not connected to your furnace. Unlike an immersed coil installation where the hot water tank is connected to a furnace, a tankless water heater does not require a separate storage tank. Instead, the water heating coil is located in the furnace or boiler, eliminating the need for any additional equipment. This allows for a more space-efficient and seamless water heating process without the need for a separate tank.

Related Post:  Is Drano or Liquid Plumber Safe for Septic Systems: Conclusive Facts and Expert Advice

Can gas water heater and gas furnace be vented together?

No, gas water heaters and gas furnaces cannot be vented together. Vent connectors serving equipment with natural draft (like a typical water heater) should not be connected into any portion of mechanical-draft systems (such as 80% and higher efficiency gas furnaces). This means that during a new furnace installation, a gas water heater must be separately vented. Connecting the two would be a violation of the guidelines and potentially pose safety risks. Therefore, it is essential to ensure separate venting for each appliance.

How close can water heater be to furnace?

The proximity of a water heater to a furnace should adhere to the front service clearance requirement of 24 inches for each appliance. While most furnaces have zero clearance around three sides, it is crucial to ensure that the distance between the water heater and furnace is a minimum of 24 inches to allow sufficient access for maintenance and repairs. This clearance not only ensures the safety of the appliances but also facilitates their efficient functioning by providing suitable ventilation and accessibility. Thus, maintaining the recommended distance between the water heater and furnace guarantees the smooth operation of both appliances.

References: 1, 2, 3, 4