Questions and Answers for Rheem 12 in. Vent Length 3 x 5 in. Stainless Steel Concentric Vent for Indoor Tankless Gas Water Heaters

A:  Thank you for asking, Eddie. Our longest length of 3x5 Concentric Venting is 36 inches, which is Part# RTG20151D-1. We also offer a 24 inch, RTG20151C-1, and a 12 inch, RTG20151B. If you have any further questions, please contact us at 1-866-720-2076. Thank you and have a great day.

A:  Thank you for asking, AC. You can connect two of these together if you need a longer length. If you have any further questions, please contact us at 1-866-720-2076. Thank you and have a great day.

A:  Yes, they are made to fit together with pre-drilled holes for sheet metal screws. Note that this pipe has an inner pipe and and an outer ring, one for intake and one for exhaust.

A:  yep, I joined a few, I had a bend and joined one of these, a bend and then another on the top. you can see the screw holes at the top and bottom edges.

A:  Yes, I had to join several pieces together to not only get it high enough to go through the roof, but also with an elbow for offset. But it is not cheap, so you want to consider the shortest run, like out a side wall?

A:  Yes, these concentric exhaust and intake pipes have locking slots on the outside tube where the intake air cools, and have a silicon seal ring on the inner exhaust tube. After fitting them together, I believe a slight rotation locks them together. If the brands differ, then they may not merge perfectly, but two Rheem pipes attach perfectly and reliably. Because the intake cools the outside, no clearance is needed around the pipe, but you still need a 2 foot clearance above the roof. More is the roof is slanted, more clearance might be needed. If the water heater and roof do not line up, then you can make horizontal allowances with 2 adjustable elbows in the pipe.

A:  YES! You should get as long a section as possible to reduce joints. That makes the piping stronger. Check for length limitations and the proper termination if it is exiting through the roof.

A:  Yes, they are designed to fit together.

A:  Hey Coach11, Thanks for reaching out, This unit actually does not use that type of venting. This heater requires 4 inch Stainless steel venting manufactured by a company called heat fab their phone number is 800-992-8368

A:  I believe the same vent concentric intake and exhaust pipe is used by both Rheem and Paloma because they are the same with just different names. But that is only from reading and not from actual experience.

A:  Best to check with the Manufacture, They might require something special for safety and warranty.

A:  I am not sure, but I do not think so. First of all, I am not familiar with the Paloma PTG2-42PVP, but found an online manual for a Rheem PTG2-42PVP, https://www.manualslib.com/products/Rheem-Ptg2-42-Pvn-Pvp-330558.html The model being the same makes me think they likely are the same, just rebranded. And that describes a single wall, 3", stainless steel exhaust vent pipe. The pipe you are asking about is a concentric, dual intake on the outside, and exhaust on the inside. The Rheem manual describes requiring the room where the water heater is installed as providing the intake air instead of it coming from dual vent pipe. Since the dual pipe is stainless, can it still be used? Maybe. The extra concentric outer layer may just make installation safer. But this pipe has silicon seals and a particular fit, and is expensive, so I would be cautious about going that route?

A:  I believe that 3x5 concentric stainless ducting is generic. Which means it should work for any device that requires 3x5 concentric venting. Just measure the size of the fittings on the device you want to connect to. The inner is the exhaust, and that is the part that need to be stainless to prevent corrosion from sulfites in the exhaust. That is what has to be exactly 3" in diameter. Then the outer is the intake, and is 5" in diameter. Each piece has a high temp silcon O-ring gasket that has to fit right, but that likely would be no problem as long as the dimension if correct. I would assume that Rheem makes devices for all 3 styles of exhaust. The low efficiency devices likely use single wall, insulated 3" exhaust. The medium efficiency uses this 3x5 concentric duct for exhaust and intake. The high efficiency used 2 separate 3" PVC plastic duct. As long as it is medium efficiency with concentric 5" intake and 3" exhaust together concentrically, I would assume this would be the right venting for the device.

A:  This is the only pipe that an be used with there tankless water heater. Check manufacturing recommendations for the water heater you are thinking of purchasing, this is slightly differant than normal piping for water heaters/

A:  You can use it with any application that requires Concentric vent pipe.

A:  Thank you for asking. This would be for a Tankless Gas Unit only

A:  I think you just need to have the in and out air flow. It’s two pies for for the inlet and one for the out let. If your just looking for the exhaust I’m sure you can find a cheeper option

A:  Yes, this can be used for Mid Efficiency Tankless gas water heaters.

A:  When you buy 3x5 concentric venting, all the pieces should ideally be the same brand. That is because the inner exhaust has a special seal, usually high temperature silicon, that prevents leakage back into the intake air. While 3x5 concentric venting is expensive, that is because it is stainless steel, and will last forever essentially. So it is worth the value. Home Depot has the appropriate cap for the 3x5 concentric venting it sells. The brand is Rheem I believe. https://www.homedepot.com/p/Rheem-3-in-x-5-in-Stainless-Steel-Concentric-Tankless-Gas-Water-Heater-Vertical-Venting-Termination-with-Cap-RTG20151P/202798878?MERCH=REC-_-PIPHorizontal2_rr-_-202798879-_-202798878-_-N There may also be other ways to split the inner and outer to separate vents, because that is usually how it is done if venting out through a wall. But I am less familiar with 3x5 concentric wall vents. https://www.homedepot.com/p/3-in-x-5-in-Stainless-Steel-Low-Profile-Termination-Vent-for-Tankless-Water-Heaters-RTG20234/203215764?cm_mmc=Shopping%7CG%7CVF%7CD26P%7C26-10_WATER_HEATERS%7CNA%7CPLA%7c71700000033150351%7c58700003868932468%7c92700031086623210&gclid=EAIaIQobChMIjLqhyNmN3AIVgx5pCh1WgANREAYYASABEgLN9fD_BwE&dclid=CKXm6tLZjdwCFUyMaQodgqcArQ

A:  Just a added note, check out Home Depot / Rheem model # RTG20151P / Internet # 202798878, sales for $80.00

A:  Thank you for asking. The part number for the Vent Cap is RTG20211.

A:  Rheem 3 in. x 5 in. Vertical Concentric Termination Vent Kit Stainless Steel for Mid Efficiency Tankless Gas Water Heaters Model # RTG20211 Internet #203041258 https://www.homedepot.com/p/Rheem-3-in-x-5-in-Vertical-Concentric-Termination-Vent-Kit-Stainless-Steel-for-Mid-Efficiency-Tankless-Gas-Water-Heaters-RTG20211/203041258

A:  Since my 3X5 was vented thru the wall, I went with the 3X5 termination piece, However, Home Depot does sell a cap for vertical venting, and it too, should be stainless 3X5 approved.

A:  This vent segment has an 35.66” overall length

A:  The length of the 36" 3x5 concentric vent pipe is 36", and the outer diameter is 5". But I can't think of the point of the question unless you are having trouble figuring out how to get something to match up? And the way I do that is by using a set of 2 45 degree angle elbows. Using 2 45 degree elbows, you can make sure most things you need to accommodate will be able to fit correctly. You don't really want to cut these concentric vent pipes to a different length if you can help it, because of the inner and outer seals.

A:  It’s 36 inches in length. The inside exhaust vent pipe is 3 inches in diameter and the outside concentric intake vent is 5 inches in diameter

A:  The length is 35 inches.

A:  Not sure what you mean because this is labeled as being 36 inches long. They also sell one that is adjustable in length, as well as elbows. You can not cut this to other lengths because of the dual seals.

A:  Not sure what you are asking because this is specified as being 36" in length? But they do sell other lengths that are shorter. It is just that the longer runs are the cheapest way to go if possible? Since this is concentric, I also believe one likely should not cut it, and instead rely on a pair of 45 degree elbows it one need some fine tuning of the length.

A:  35”

A:  36 inch plus about 1 to1 1/2 inch for connection to next pipe or termination, or what ever you are planning to attach to it. They also have a 3 X 5 pipe that you can cut to the size you want for fit.

A:  36 inches length. Inside exhaust vent 3 inches diameter. Concentric outer intake vent is 5 inches diameter

A:  36 inches long.

A:  Thank you for asking. What you are describing is known as a concentric vent, and out product does meet the specifications you supplied. However, whether use of our venting is allowed by your warranty is unknown. Before purchasing, please contact AO Smith.

A:  Right. The outer 'ring' carries cool air from outside. Only the inner ring is hot. Outside is cool or warm to the touch.

A:  While the venting does not require any clearance to combustibles, it is completely dependent on local code whether or not it is necessary to install fire stops.

A:  Yes. The inner core of the Concentric vent expels heat, the outer portion of the vent pulls fresh out door air to the heater, the effect is slight warming. A 1" clearance from combustibles is a code requirement.

A:  I did not use one but this is in my garage and only went through the roof.

A:  The answer to whether or not Rheem vents need fire stops has many parts. First of all, the high efficiency tankless water heaters do not even need metal venting at all, and use PVC. It is only the medium efficiency that still need metal venting. But since the stainless steel venting for this is concentric, the outside never can get hot, and so it needs no additional spacing from combustibles that is normally obtained through fire stops. However, if going vertically through multiple floors, it is still important to seal off any opening that any fire in one floor might travel through to propagate into a higher floor. So while you do not need firestops in order to maintain distance from combustibles, you might still need firestops just to plug up the holes around the round venting. But if you can seal the opening around the venting without firestops, then they are not necessary. The concentric venting can not get hot enough to create any risk in contact with combustibles. Specifically the 3x5 designation means the outside is 5" in diameter, and the hot exhaust portion inside is 3" in diameter. There are also high temperature silicon seals at the inside joints.

A:  I'm not sure, but you can connect these to make 10 feet, they seal very nicely. Home Depot can contact the Manufacture to see if they have something that can be special ordered.

A:  Yes. Concentric vent kits are designed to easily attach with screws included.

A:  Yes, the point of these 36" long 3x5 vent pipes is that you can chain together as many as you need or want. There are inner and outer seals on each end, so you have to be careful to put them in the right direction. Start from the heating device and work your way up. You can also go sideways out a wall with these medium efficiency systems.

A:  Yes, you could connect 4 of them to give a 12 foot stack. They cannot be cut. I believe there are longer lengths available

A:  Yes, each piece has a male and female end, with a silicon heat proof seal. They are a tight fit, and each piece comes with 3 screws. So you can add them together for any length you want. Remember to put a cap piece on the top.