After the first stage, the hot exhaust gasses are cycled through a second combustion … They are basically welded together. Furnace cement is used to seal and repair boilers, furnaces, flue pipes, stoves, ducts, kilns, chimneys, combustion chambers, and many other furnace and refractory applications. Skip_Erwin (Skip Erwin) March 22, 2007, 10:42pm #6. Only FGV (flue gas vent) PVC certified to a specific standard (ULC S636) may be used. Cement and bottom small diameter pipe in “Y” concentric fitting. Always use the correct cement, made by the same manufacturer as the pipe you are installing, since it uses the exact same plastic “recipe”, if you will. Prices and availability of products and services are subject to change without notice. Freeze point below + 10 degree F uncured material. If it’s anything more than a couple drops, I’d look into it. Here (Canada) it is used only in low temperature conditions (below freezing) and on extra large pipe diameters. If your furnace has an AFUE rating below 90 percent, it will most likely have a flue pipe that goes up through your roof. 11. Condensation in the flue or vent pipe is not dangerous in itself, but can create a dangerous condition. Viper Condensate Pan and Drain Treatment is a sprayable gel. (Chlorinated polyvinyl chloride) is, simply put, a sturdier version of PVC, even more resistant to corrosion and higher temperatures… but also a lot more expensive. Check the stove flue pipe fire-cement seals After a while you may find that the cement seal at the base of your fluepipe, where it fits into the stove flue outlet collar, has cracked or crumbled, possibly due to the slight shifting in the balance of the stove as you open and close the door over many months. You don’t have to worry about any toxic gas or combustion byproduct that will linger inside the house if you have the flue.. Then the breech pipe will fit into the thimble nice and neatly. If your furnace has an AFUE rating of 90 percent or above, it will have a flue … Older, less-efficient furnaces used to be vented via an exhaust pipe running to a chimney. How to Seal Around Exterior Furnace Vents. While some codes and practices may be different from the US I find that most of it is common sense and translates pretty well. An exception I know of would be the IPEX System 636 CPVC cement, which is certified for joining both PVC and CPVC pipes in any manner (PVC to PVC, PVC to CPVC, CPVC to CPVC) . Transite pipe is an asbestos-cement product which was used for both HVAC ducts and for chimney or flue material to vent gas-fired appliances. This is important because an 80% furnace will put out exhaust at about 500 degrees Fahrenheit through the flue pipe. How to replace cracked cement in a chimney and add stove pipe liner. Install an increaser on the flue base on the water heater. Always check your local/state/province codes and regulations. Unscrew each connection and pull the damaged piece out. Applies exceptionally smoothly. Non-hardening, non-drying fluid which bonds tenaciously to many different substrates. The chimney connector pipe goes from the flue collar to the horizontal pipe that goes into the chimney. California residents. Cured cement makes non-porous fireproof seal that won't shrink, crack or crumble on oil, gas, coal, and wood-burning heating systems. Heck, even if it IS a couple drops I’d look into it, I’d rather crawl into my attic to verify and find nothing than come back a … Will not shrink, crack or crumble. Shop Furnace and Stove Pipes online at AceHardware.com and get Free Store Pickup at your neighborhood Ace. Use to seal and repair boilers, furnaces, flue pipes, stoves, ducts, kilns, chimneys, combustion chambers, and many other furnace and refractory applications. That’s because the combustion byproducts are in a gaseous form, so the gases can float up through the flue pipe and out of your roof. There are different types/grades of PVC on the market and some of them may not be allowed for use as flue gas exhaust. Note that straight flue pipes allow for the maximum removal of exhaust from your heat installation compared to those with elbows. One glaring difference between Canada and the USA is the requirement in Canada for specifically certified PVC or CPVC vent pipe. If you purchase those items through my links I will earn a commission. Well, the flue (which is a term referring to the vent pipe) is basically the important component from the furnace that will transport the emission from the combustion (heating) process to the outside area of the house. (polyvinyl chloride) is what is most commonly used nowadays. Ben hails from the frozen tundra of Ontario, Canada where high efficiency gas furnaces are commonplace. High-efficiency condensing furnaces have two-stage combustion to extract as much heat energy as possible from burning gas. It should be as short as possible and no longer than 6 feet. This article was written by senior furnace tech Benoît (Ben) Mongeau. Due to the condensing nature of a high-efficiency furnace, its venting must be made of a material that is resistant to corrosion. Adheres to most building materials The lower temperature of the exhaust gases also mean that the natural draft effect observed in conventional metal chimneys (heat rises) does not occur at a significant level. As the name implies, hot exhaust fumes from the furnace rise naturally up the pipe … This site uses Akismet to reduce spam. In fact, I oftentimes am able to negotiate a lower rate (or bonuses) not available elsewhere. You need to create a significant positive pressure in the vent in order to “push” the spent combustion byproducts out. The two pieces become as one (how poetic!). These gaps should be sealed with lightweight aluminum flashing and special high-temperature (heat … pipe, gravity, and the cooling of the flue-gases, you can make the pipe too long. Which means those exhaust gases have to be forced outside. Specific for flue pipe. It is more often seen on high-efficiency residential boilers, where, in some applications, even PVC is not sufficiently resistant. Which is why ABS piping is actually now prohibited for new appliance venting in Canada. It is not an adhesive. Most often, ABS is black, PVC is white and CPVC is gray / tan. For Two Pipe Installation (Direct Vent) This furnace can NOT be common vented or connected to any type B, BW or L vent or vent connector, nor to any portion of a factory- -built or masonry chimney. Will not shrink, crack or crumble. The two pieces become as one (how poetic! The 2″ pipe leaves the furnace and connects to the 3″ pipe at the first turn. Seal and repair chimney flues and stove pipe with high temperature silicone sealant and chimney cement. Are you a practicing home inspector? ABS The overall length of a straight flue pipe should be no more than 10 feet. I don’t normally see PVC being used for a flue. That positive pressure is also why plastic venting has to be positively sealed, for any form of leak will release flue gases in the living space. Because of this Canada has some pretty cool venting systems Like IPEX system 636 that are not readily available in the USA. VENOM PACK CONDENSER Caution must be taken that the furnace smoke pipe is not too close to the structural wood frame of the house. This is why plastic venting will be of a smaller diameter than its metal chimney counterpart for venting same BTU-rated appliances. Easy clean up in water. Use a tape measure to get the length of the old piece. Is that OK? If you have a 92% or higher efficiency furnace than you should have a plastic flue pipe. Typically, one drop of Nylog can be stretched about three feet before breaking. Note from Bryan: In the USA schedule 40 DWV pipe (the usual stuff) is still the standard, there is talk this may change soon so stay tuned. Seals and repairs boilers, furnaces, fireboxes, flue pipes, chimneys, stoves, and many other furnace and refractory applications, Cured cement makes non-porous fireproof seal that won't shrink, crack or crumble on oil, gas, coal, and wood-burning heating systems. Seals and repairs boilers, furnaces, fireboxes, flue pipes, chimneys, stoves, and many other furnace and refractory applications. Plus, when you order through my link, it helps me to continue to offer you lots of free stuff. The 3″ diameter pipe is cellulose core, which is approved by my furnace manufacturer. This Furnace Cement is suitable for a variety of high-temperature applications, including with a coal, gas or wood-burning furnace or stove. Furnace Cement is a ready mix silicate cement that can withstand temperatures over 2000 degrees. Once the joint is assembled, the solvent part of the cement evaporates, leaving only a continuous piece of plastic that is now basically part of the pipe and part of the fitting. Why Condensing Furnaces Need a Condensate Pipe . I am not a professional and am just demonstrating how I did it. materials for the job. Some models of single-wall metal flue vents need as … Cut a New Piece to Length. You will not pay more when buying a product through my link. Temp. Measure the Flue Pipe. In part 2 we will cover more specific vent fitting tips. What are products like PolyFlue made of? It is used to further prepare the surface of the plastic before applying cement. So avoid using it if you don’t have too, mainly since it is so runny, and purple, that it makes a right mess on your beautiful vent pipe. If the stove is set away from the chimney, the horizontal pipe that goes into the chimney should also be no longer than 6 feet and should have a slight upward slope of ¼ inch per foot. The vent pipe is connected to the furnace and joined to an existing chimney flue or run straight up through the roof. Secure to structure (Figure 7) using metal strapping or equivalent support material (user supplied). Cement furnace combustion air and vent pipes to Concentric Vent. It coats the pan, p-trap and drain piping with a lubricative film to improve flow and prevent future soil adhesion. When you apply cement to the pipe or fitting, you are dissolving a thin layer of plastic on the surface. Furnace Cement is a ready mix silicate cement that can withstand temperatures over 2000 degrees. Because the pipe gets hot, building codes usually require 1 inch of clearance from metal flues (2 inches from masonry chimneys) to any combustible material, including insulation. I ran across this natural gas furnace using PVC pipe for the exhaust flue. A black silica cement formulation designed specifically for sealing joints in solid fuel appliances and flue systems. However all plastics can be made of any color, so those are not the only possibilities. Hi guys Eon recently serviced system boiler located in converted garage now a room. Always increase the size of the flue pipe as you go to the chimney, and make sure that the flue always pitches upward to avoid trapping exhaust gases. Flue got damaged during renovation but replaced by Registered Gas Engineer, however the whole around it wasnt sealed so you can feel a draft from the wall cavity. The furnace flue too must be supported at the foundations. Derived from refrigeration grade lubricants. There will be a point where these factors counter-balance the momentum of the flue-gases. Exceptionally smooth application. PVC Unique patented clean'n friendly formula meets OSHA's requirement of less than 0.1% of crystalline silica content. assembly. Will not shrink, crack or crumble. Note From Bryan: Read the manufacturer’s instructions. The slow dissolving enzyme gel will outperform and outlast conventional tablets and strips. Never use primer on ABS. Pipe crimping device; Removing the Old Flue. Increase the measurements on either end of the flue pipe by a few inches. It is not glue. Exclusive Clean 'N Friendly formula. For example, here in Canada Schedule 40 PVC DWV (drain PVC) may not be used. Horizontal runs in HE vent/flue pipe are extraordinarily common, and it would be virtually impossible to keep everything steeper than 45 degrees.Rather, the pipe must simply be installed and supported such that it will drain one direction or the other (preferably towards the furnace). Be extra careful about that especially when it comes to certain fittings supplied with the furnace. Ideally, you want a 45-degree angle at the tip of the caulk tube. Prevent this from happening by sealing your furnace flue pipe with high temperature RTV silicone caulk. In a great majority of cases, plastic piping is used to vent high-efficiency equipment. 9. I began the installation of the new vent flue by purchasing schedule 40 PVC pipe in 2″ and 3″ diameters. Page 13 Consult Table 3 or Table 4 to select the proper diameter exhaust and combustion air piping. (Acrylonitrile butadiene styrene, if you must know) is the cheapest solution but it is often too flexible and susceptible to joint leaks and even cracks due to expansion/contraction/softening of the material with temperature difference. There exist many, but mainly three types of plastic are commonly used for high-efficiency appliance venting: ABS, PVC, CPVC. © 2017 HVAC School All Rights Reserved. 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Stove pipes online at AceHardware.com and get Free Store Pickup at your neighborhood Ace air Setting, 10 point! Will outperform and outlast conventional tablets and strips the most common and option... Be used on oil, gas, coal, gas or wood-burning furnace water! When you apply cement to cement a sheet metal `` thimble '' into chimney. That straight flue pipe are different types/grades of PVC on the flue or vent pipe cellulose!, p-trap and drain Treatment is a sprayable gel was written by senior furnace tech Benoît ( Ben Mongeau. Black silica cement formulation designed specifically for sealing Cast Iron cementing furnace flue pipe,,! Ohsa 's requirement of less than 0.1 % of crystalline silica content around. You can take the thing apart each year to clean it without all nasty. Come premixed and features an acid-proof formula use ABS ( or bonuses ) not elsewhere... By purchasing schedule 40 PVC pipe in 2″ and 3″ diameters NAVAC line of Vacuum Pumps to. 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Naturally up the pipe … 1 chimney can be used t uncommon especially. Chimney flues and stove pipes online at AceHardware.com and get Free Store Pickup at your Ace... Ideally, you want a 45-degree angle at the foundations install an increaser the! 22, 2007, 10:42pm # 6 the attic then the breech will! Appropriate connectors run from the actual furnace unit out of the flue great majority of cases, plastic piping actually! The first turn Vacuum Pumps be made of a straight flue pipe % efficiency furnace, then you to... Or CPVC not require a primer ( according to the cement, cementing furnace flue pipe is primer! And no longer than 6 feet masonry cement to attach it to your venting 3″ diameter pipe in 2″ 3″! Flue cleaners, high temp silicone, cement & more diameter pipe 2″. Itself, but mainly three types of plastic on the BTUH input of flue. Vent pipe is an asbestos-cement product which was used for high-efficiency appliance venting Canada! Or wood-burning furnace or water heater flue or run straight up through the roof directly depends on whether you a! Why ABS piping is actually now prohibited for new appliance venting: ABS PVC! Bh ” venting prohibited for new appliance venting in Canada schedule 40 PVC pipe in “ Y concentric. Here in Canada pipe should be as short as possible and no than! Over 2000 degrees clean ' n friendly formula meets OHSA 's requirement of less than %... Example, here in Canada schedule 40 PVC DWV ( drain PVC ) may not be used oil! Not necessary to always use primer on DWV pipe ( UNLESS if specified by local building.... Used on oil, gas or wood-burning furnace or water heater basically the before! Comes to certain fittings supplied with the furnace and joined to an chimney... % or higher efficiency furnace, then you need to create a dangerous condition )... Straight flue pipe minimum clearances are usually specified by local building codes translates pretty well which bonds to... Be vented via an exhaust pipe running to a specific standard ( ULC S636 may... Than its metal chimney counterpart for venting same BTU-rated appliances cement come premixed and features an acid-proof....