The appropriate flue size for a water heater depends on the water heater’s BTU output and the manufacturer’s recommendations. Common sizes are 3 inches and 4 inches in diameter.

Twin Wall Flue by Flue Direct, the leading UK supplier of HETAS approved flues; twin wall flue pipe, flexible flue liner, flue for wood burners and all flue supplies for log burners, multi fuel stoves, wood burning stoves, fires, commercial and biomass boilers. The size of the vent needed for a 40-gallon water heater depends on its BTU rating and the manufacturer’s recommendations. Common sizes are 3 inches and 4 inches in diameter. The distance from the flue to the wall should follow local building codes and the manufacturer’s recommendations for clearance distances.A reducer can be used to transition from an 8-inch to a 6-inch stove pipe, but it must be done in accordance with the manufacturer’s guidelines and local building codes. Flue Direct is built on our reputation, excellent delivery times, unbeatable prices and advice service. Please ensure that your goods have arrived before booking your installation service. If you have any queries please feel free to get in touch. For a water heater, the size of the chimney liner depends on the BTU rating of the water heater and the height of the chimney. It is essential to follow the manufacturer’s guidelines or consult a professional to determine the appropriate size. Twin wall flues will heat up when in use as they transport the hot stove gases away from the appliance, the outer part of the flue can be over 90o C or 194o F. The temperature of the twin wall flue will vary depending on: New Swept Elbow - This is the latest product to be added to our Premier Flue Pipe range. Outstanding performance and efficient gas flow are only two of its features. It is aesthetically pleasing and easily cleaned which are important factors when choosing for domestic appliances. Available in 5" and 6"diameters and three angles 90°, 110° and 135°. Also available with an optional blended door for ease of cleaning.

Yes, it is generally recommended to close the flue when the appliance is not in use to prevent heat loss and drafts. Our Flexible flue liner is available in both 316 grade stainless steel and 904 grade (Lifetime warranty). Both are suitable to reline your chimney for use with a multi fuel stoves and wood burners and are HETAS approved, for further information please refer to the flexible flue liner section. A larger flue can provide better draft and improve the appliance’s efficiency, but it must be proportionate to the appliance’s BTU output and follow the manufacturer’s recommendations. Flue diameter is measured as the inner diameter of the flue pipe, which is the open area where combustion gases pass through. The maximum distance for direct venting a water heater depends on the manufacturer’s guidelines and local building codes. Typically, it can be up to 40 feet horizontally and 100 feet vertically.Adjustable Flue Pipes - A variety of telescopic lengths. The band is tightened to secure the joint, this item is non-load bearing and support must be providedimmediately above the adjustable pipe. A twin wall flue is required when a chimney breast is not already present and cannot be installed. Creating a way to remove emissions from wood burning and multifuel stoves from the building safely. The angle of a flue pipe should have a minimum upward slope of 1/4 inch per foot to promote proper venting.

What size flue do i need? HETAS regulations state that there is a minimum flue size of 150mm / 6 inch for any stove (on which wood could be burnt) unless it is Defra Exempt. Therefore, you may need to increase your flue size from your stove outlet using an increaser e.g 5 – 6 inches. Please talk to us for further information if required.

Twin Wall Flue

An open flue can allow significant heat loss, especially in cold weather. It is recommended to close the flue when the appliance is not in use to prevent heat loss. Premier Flue is a comprehensive range of Vitreous enamelled flue pipe. Manufactured in accordance with ISO9001-2008 using superior grade low carbonsteel and coated to the highest standard. Suitable for oil, gas and Solid Fuels, for domestic heating appliances. Finished productshave an internal and external vitreous enamel coating to offer extremely high resistance to heat and toxic or corrosive gasses meeting with the requirementsof BSEN ISO 28706 - 1:2011.

Flue installation should be done by a qualified professional to ensure proper sizing, venting, and compliance with building codes for safety and efficiency. The length of a flue pipe can vary depending on the appliance’s BTU rating, the type of fuel used, and the manufacturer’s guidelines. It is essential to follow their recommendations.In summer, when the appliance is not in use, it is generally recommended to close the flue to prevent heat loss and avoid drafts. Water heater vents are typically made of galvanized steel or aluminum. Stainless steel vent pipes are also commonly used for high-efficiency appliances.