This guide provides a step-by-step guide on venting a tankless water heater, ensuring its safe and efficient operation. It covers different venting options, required materials, components, and how to calculate the correct vent pipe size and length. Tankless water heaters can be vented through the side wall or roof (high-pressure version), creating more flexibility and placement options.
All indoor tankless gas water heaters must be vented vertically or horizontally to the outdoors using factory approved venting material. It is not recommended to use the existing vent pipe from an old gas tank water heater, as it may not be compatible with tankless water heaters.
Tankless water heaters can be vented in two ways: power-vent or direct-vent. Power-vent units use indoor air for combustion and simply vent the exhaust to the outside. A natural gas tankless water heater in a small space requires both a fresh air vent and an exhaust vent, which means two vents with three-inch diameters.
Installing steel or PVC venting depending on the model you purchase is recommended. Vertical vent or horizontal vent can be used, and tankless water heaters can be vented in either power-vent or direct-vent systems. Proper venting techniques are essential for the safe and efficient operation of your tankless water heater.
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What type of venting is used for a non-condensing tankless unit?
Non-condensing tankless water heaters have a heat exchanger that heats water as it flows through the unit, venting hot exhaust gas. They require metal venting material to tolerate the higher temperature and corrosive nature of the exhaust gas. Non-condensing tankless water heaters don’t need a drain as the exhaust gas doesn’t cool or condense inside the unit. Condensing tankless water heaters have a secondary heat exchanger that captures heat from the exhaust gas and uses it to preheat cold water before it’s fully heated by the primary heat exchanger. Condensing tankless water heaters require a drain and allow more types of venting material to be used.
Do condensing tankless water heaters need to be vented?
Condensing tankless water heaters have two heat exchangers, enhancing energy efficiency and reducing exhaust gas temperature. They can use various venting materials like PVC and polypropylene, while non-condensing models require metal venting due to hotter exhaust gas. Condensing tankless water heaters require a drain to dispose of condensed water vapor and may use a pH neutralizer to treat acidic condensate.
The effectiveness of condensing tankless water heaters depends on personal preferences and priorities. The choice between condensing and non-condensing models depends on individual needs and preferences.
What are the different types of tankless water heater venting?
Tankless water heaters offer a variety of venting options compared to traditional tank-style water heaters. The three main types of vents are power vent, direct vent, and concentric vent. Power vent uses indoor air for combustion and requires an exhaust vent, making it ideal for limited outdoor venting access. Direct vent, with separate intake and exhaust vents, draws in air from outside the house for combustion, making it suitable for smaller spaces. Direct vent systems are often installed near exterior walls or on the roof, providing efficient and safe operation.
What material is used for tankless water heater vent pipe?
Plastic venting materials like PVC and polypropylene are cost-effective, corrosion-resistant, and easy to install for condensing tankless water heaters. They are lightweight, easy to install, and designed to withstand lower exhaust temperatures of condensing units, ensuring safe and efficient operation. However, it is important to note that each manufacturer may have specific guidelines regarding venting materials and installation requirements. Plastic (PVC) is cost-effective, corrosion-resistant, and lightweight, while polypropylene is cost-effective, corrosion-resistant, and easy to install.
Stainless steel, on the other hand, is higher durable and suitable for noncondensing units. It is crucial to consult with a professional to ensure proper venting for your specific condensing tankless water heater.
Can you use PVC to vent a tankless water heater?
Condensing tankless water heating units offer high efficiency and lower exhaust temperatures, allowing for the use of less-expensive plastic materials like polypropylene and PVC in vent installation. Ventilation is crucial in tankless water heater installations to ensure exhaust gases are blown and dissipated outside, preventing indoor accumulation. Gas-powered tankless water heaters are among the most efficient water heating solutions, reducing energy consumption and greenhouse gas emissions by about 50%.
The tankless water heater market in the U. S. is expected to grow by 8. 7 annually over the next decade. For plumbing and heating professionals, using best venting practices, such as concentric vents, meeting local code, and opting for aesthetically pleasing designs, is essential to ensure homeowners love their installation and stay within budget during the project.
How do you insulate an indoor tankless water heater?
Insulation is essential for tankless water heaters and plumbing pipes, which are susceptible to freezing during cold temperatures. Fiberglass and heat tape are excellent options for winterizing, with various types and materials available. Applying heat tape on pipes connected to the water heater ensures water doesn’t freeze. However, heat tape only works when there’s power. Battery backup is crucial for maintaining a consistent power source, especially when homes or businesses lose power, as demonstrated in Texas. Both heat tape and battery backup are essential for protecting water pipes and preventing freezing.
Can a tankless water heater be vented into the attic?
Power-vent units require an exhaust vent and must be placed in a large room or room with vents or louvers for gas combustion. Direct-vent units can be placed in smaller spaces like attics, closets, or mechanical rooms. Tankless water heaters don’t always need two ventilation pipes, even for direct-vent units. Some manufacturers offer concentric venting, a single pipe with an inner exhaust vent and an outer intake vent.
Concentric vents provide advantages such as only needing one penetration in the wall or ceiling and being cool to the touch, unlike exhaust vent pipes that require clearance to avoid contact with the wall.
What is the code for venting a tankless water heater?
The water heater must be vented according to the National Fuel Gas Code (ANSI Z223. 1/NFPA 54) in the United States and/or Section 7 of the CAN/CSA B149. 1 Natural Gas and Propane Installation Code in Canada, as well as local building codes. The water heater should be placed close to the vent terminator, the vent collar should be fastened directly to an unobstructed vent pipe, and the vent should be easily removable for normal service and inspection.
The vent should not be connected to any other gas appliance or vent stack, avoid using an oversized vent pipe, and install a rain cap or other termination for rooftop venting. Common vents or connections from other appliances should not be connected to the water heater vent.
Do tankless water heaters require special venting?
It is of paramount importance to ensure adequate ventilation for gas-powered tankless water heaters. In contrast, electric tankless water heaters do not necessitate venting, as they employ electric burners to rapidly heat water. The variety of vents available for tankless water heaters is contingent upon several factors, including the positioning of the heater, its dimensions, and the spatial requirements associated with its installation. The optimal vent for a given residence is contingent upon a number of factors.
Can you use PVC pipe to vent a tankless water heater?
Condensing tankless water heating units offer high efficiency and lower exhaust temperatures, allowing for the use of less-expensive plastic materials like polypropylene and PVC in vent installation. Ventilation is crucial in tankless water heater installations to ensure exhaust gases are blown and dissipated outside, preventing indoor accumulation. Gas-powered tankless water heaters are among the most efficient water heating solutions, reducing energy consumption and greenhouse gas emissions by about 50%.
The tankless water heater market in the U. S. is expected to grow by 8. 7 annually over the next decade. For plumbing and heating professionals, using best venting practices, such as concentric vents, meeting local code, and opting for aesthetically pleasing designs, is essential to ensure homeowners love their installation and stay within budget during the project.
How to vent an indoor tankless water heater?
Tankless water heaters are a popular choice for homes and buildings due to their ability to draw in outside air and save up to 16 square feet of space. They can be installed outside in warmer climates, freeing up indoor space without the need for additional venting. Tankless water heaters can be vented through the roof or side wall, providing more flexibility and placement options. Condensing tankless water heaters are up to 95 more efficient than non-condensing units and emit a cooler exhaust gas. The exhaust vent can be made of PVC or polypropylene, reducing installation costs.
Tankless water heaters with a concentric vent design offer additional safety benefits, as a 5″ vent contains both intake and outtake pipes, making it cool to the touch and preventing leaks. Recess boxes are available for non-condensing tankless water heaters, allowing them to fit inside the house’s framing. Pipe covers and creative termination points offer aesthetically pleasing venting solutions.
To plan your installation, find a tankless water heater dealer in your area and consult the Tankless Buyer’s Guide for more information.
📹 Myth #3 – Venting is too expensive on tankless units.
The Tankless Truth is we offer affordable concentric venting solutions on our tankless water heaters and can use 2-inch PVC on …
I need some information… I live in a mobile home where my hot water take sits within inches of my electrical panel I’m having difficulty finding out a mobile home system that works with propane . We loose power a lot and we have a generator I feel like I need to move it away from the electrical. I think to hire an electrician to move my panel will be very expensive compared to upgrading to hot water tankless system. Suggestions would be so helpful. I’m a single mom and don’t want to make a expensive mistake I’ll regret
Not exactly. About two years ago my gas tank water heater was leaking after 15 years, and I contacted Home Depot to purchase and install a tankless water heater to replace my gas tank water heater located on the second floor of my townhome in a closet near the outside wall (with accessible attic space above it). My unit is an end unit townhome and the siding was Hardie Plank where the vent could have gone out. The installer came to give me a quote and said they said they would not even do a second story vent to the outside wall of my townhome, due to the height (they didn’t have ladders that would go that high and didn’t have insurance to cover that). So although actual cost of the vent pipes for a tankless water is a nit, the installation cost may not be even close to reasonable unless it is on the first floor. This was the only plumbing installer that Home Depot used in the Atlanta area. Plus I would have had to pay a plumber to run a 3/4″ gas line (the tank water heater was using a 1/2″ line), and pay a licensed electrician to run 120V electrical power to the location (the existing gas tank water heater uses a thermocouple to run the thermostat). So, even if the cost of the pipes is a nit, the total cost may be quite high.