navien tankless water heater pressure relief valve

Garageboy Member Posts: 3. warranty from date of purchase. What is the purpose of a thermostatic mixing valve above a water heater? How do you drain the condensate in a tankless water heater? Please try again later. No required pressure relief valve at hot water side, because piping is CPVC. Allows users to adjust temperature, set operational settings, and display operational info. What can I do to make my water heater last longer? Is a PhD visitor considered as a visiting scholar? The best answers are voted up and rise to the top, Not the answer you're looking for? Is it possible to rotate a window 90 degrees if it has the same length and width? The one feature that make this model stand among the rest is its impressive flow rate. But why is the relief water discharging water in the first place? There isnt a single solution for excessive water pressure. What is the difference between a regular water heater and a direct vent water heater? You accept the use of cookies as described in our, Learn more aboutHAir Kit AHU Optimizer, Learn more aboutNaviLink Lite Wi-Fi Control, Learn more aboutReady-Link Manifold System for NPE and NPE-2 Series, Problem Solved: Gandy Installations Saves Customer Enough Space for a Refrigerator, Problem Solved: Steve Hosack of SC Hosack Plumbing Upgrades His Hair Stylist to Navien, Ways to save money on your water & electric bill. I just need to find out how to plumb the output of the neutralizer. NFB-C series parts kit designed to help service in the field. Where are gas water heaters not allowed to be installed? If the pressure is less than 80 PSI, its all well and good. However, if the issue is beyond your understanding and you arent comfortable with plumbing, youll need to contact a plumber to do the work. 1 year warranty from date of purchase warranty from date of purchase. Where Is the Water Heater Pressure Relief Valve? After a time, heaterrelief valvescorrode or leak due to a faulty seal. When is a water heater drain pan required? Where do I find the water heater in a mobile home? How long does a condensate neutralizer last? The liquid comes out through this auxiliary route, relieving the heat and pressure within the water tank. Allows for combined space heating and domestic hot water when paired with a recirculation pump (ComfortFlow on NPE-A and NPE-A2). What does it mean when a water heater Temperature/Pressure Relief (TPR) discharge pipe is "trapped"? When the Navien Water Heater / Heating Boiler is at maximum burn, check the inlet gas pressure reading on the manometer, it should read between 3.75"and 10.5"WC for Natural Gas / 10.5". $599.00. Can I plumb it with the relief valve? Page 34 Code in Canada and in accordance with all applicable local building codes. If youve been having issues with your water heater recently, you might find that youre paying high energy bills, not getting access to hot water when you want it, or your water pressure is low. Quote from the video: This is for safety reasons. Navien Premium Efficiency condensing tankless water heaters are the #1 selling high efficiency condensing tankless water heaters in North America. What is the difference between a regular water heater and a power vent water heater? Sometimes, theres a third reason why water discharges from the relief valve, and that is that if your relief valve is faulty or not properly sealed. Is a catch pan and drain piping required for a replacement water heater? Open the pressure relief valve. Usually, you can find it on the top or side of this appliance. If your water temperature is 210 F or higher, then its likely that your relief valve is discharging water due to the water overheating. It connects to the condensate drain port of the water heater by using connectors included with the neutralizer kit. To get started, identify where the relief valve shut off is. Pressure relief valves. Condensate neutralizers can last many years without needing to be serviced apart from replacing the media. What does it mean when a tankless water heater is condensing? Required Breaker:4 x 40 A. The manual for Titan electric water heaters, for example, does not require a pressure relief valve, except if your water supply piping is plastic. If that's not an option you'll definitely want to maintain your neutralizer and perhaps test the condensate with pH test strips from time to time and simply pipe it to the closest floor drain. We work so hard all day, so its only right to go home and run a hot bath to []. Navien Plumb Easy (Lead Free Isolation) Valves 3/4"with Relief Valve V2. Sleek and compact design with digital output temperature display. to work on NPE and NPE-2 series units. Ready-Link Commercial Boiler Rack System Make sure that it doesnt come from the valve before replacing it. It serves as a filtration device for the acidic condensate created during the combustion process in gas-fired, high-efficiency appliances. Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater? Everything went well, I turned on the cold input and wham, water just started gushing out of the relief valve. If the water in the heater reaches a temperature of 210 degrees F, the T&P valve will open and release water until the water temperature is reduced. There could be a rupture as a result. CC, CR, NR & NP series parts kit designed to help service in the field. designed for infield assembly for indoor and outdoor installations. Here's how it works. We have fast FREE SHIPPING on all orders over $99 and ship all orders within 1 business day. The valve itself has been screwed into the threaded inlet. In the case of both excessive pressure and temperature, the relief valve tends to discharge water in large quantities. If so, is it still a good idea to have one installed or does that fact that the heater is tankless make these items not necessary? Or fastest delivery Wed, Mar 1. For this reason, it cuts installation time by half. In this case, you can quickly get a new relief valve from a local hardware store and replace it on your own with a few tools. have a Navien tankless hot water heater that, for no reason, it turns off periodically. Add-on. This can be frustrating, but whats the cause? This valve also ensures that there arent any leaks in your water heater, which would lead to low water pressure when you want to use it to wash the dishes or take a shower. Allow the filter to dry completely. Good post Jeff. GoTankless Service Department - 647-925-1930 ( GoTankless is a trusted tankless specific company operating out of Toronto, Ontario) Navien Technical Help Line - 1-800-519-8794 (Great solution for the Do It Yourself crowd) Navien Warranty details - Find out more HERE (should be accurate for Canada and Ontario) Additional Issues - Read Here. Incoming cold water flows around the coil and collects most of the heat. Condensate pump is not emptying properly. As water is removed through the T&P valve, cold water enters through the inlet and mixes with the water in the tank. Required fields are marked *. Such a bit of unburned gas is normal before it gets a good burn going. Gas-fired tankless water heaters will usually require a pressure relief valve, while electric on-demand water heaters may not. August 24, 2021 by Hubert Miles. Instead of sending hot exhaust gases out the flue, which wastes energy, this heater blows them through a coil at the bottom of the tank. This condensing water heater has a BTU rating of 19,900199,900 per hour. Secondary loop manifold designed to work on NCB-E, NFC, NFC-H, NHB, NFB and NFB-H models for fast, clean installations. Page 1 Navien Condensing Water Heater Manual NR-180 (A) NP-180 (A) NR-210 (A) NP-210 (A) NR-240 (A) NP-240 (A) If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Though I understand what you mean. Brief content visible, double tap to read full content. Expansion tanks and pressure relief valves serve two different purposes. Is a catch pan and drain piping required for a replacement water heater? Lead-Free isolation valve kit with relief valve 3 valve set: Cold, Hot, Recirculation Return. The manufacturers typically only require a pressure relief valve, not the combination temperature and pressure relief valve that is necessary for tank-type water heaters. Required for NPN-U outdoor installations. Does a tankless water heater in an attic require a drain pan? 6 units NPE, NCB, NFC, NFB and NHB; 3 units NFB-301C; 2 units NFB-399C. This purpose of the relief valve is to discharge water in two cases: When either of these takes place, the relief valve is activated, and the excess hot water flows out the relief valve. Replacement media for residential neutralizer. Also, construction methods and materials vary in different parts of the country and it is possible that important issues related to your area may not be covered here. If your water heater pressure relief valve is working, this is when it will open. Only the size of a small suitcase, the natural gas RU160iN model is compact, easy-to-install and perfect for indoor locations. Make sure you pipe your pressure relief valve down to within 6" of the floor and not into the drain maintaining 3/4 inch diameter all the way. You must log in or register to reply here. Once the temperature and pressure returned to safe levels, the water heather pressure relief valve closes. Temperature, pressure, or a faulty valve. An expansion tank provides the excess hot water that flows back into the inlet pipe, a place to go preventing the pressure from becoming excessive and water from discharging via the relief valve. Ready-Link Rack (V3) Add-on. The manufacturer said to check my water pressure. Do I need a thermal expansion tank if I already have a pressure tank? Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater? FREE delivery Tue, Feb 21. Water heaters located in the garage may terminate on the garage floor with the same . https://www.google.com/aclk?sa=L&ai=DChcSEwjZsrDb78zgAhUOtrMKHQFmBB8YABAIGgJxbg&sig=AOD64_3f3Fc_0mYzjmXXWbHAYQvAGUPvyw&ctype=5&q=&ved=2ahUKEwiJ5abb78zgAhWCZd8KHSvbAk0Qwg96BAgLEBA&adurl= this one is 50 bucks. The reason its there is to keep you safe in case the water pressure is too high. Make sure the new TMP valve is in the closed. Remove the filter from the plastic assembly and clean it with a toothbrush, and clean running water. How does a contractor determine the water performance rating needed for a sliding glass door? If its still between 40-80 PSI, the pressure isnt the problem here. Ensure that the maximum BTU/H rating on the . We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. Navien introduces NaviCirc, the Navien recirculation valve designed for use with Navien NPE-A series tankless water heaters to provide recirculation of domestic hot water in applications where a dedicated return line is not available. The vapor from a condensing tankless water heater is much cooler. Water-heater condensate usually has a pH of two or three, says Oshiro. Your email address will not be published. 3/4 Inch IPS Isolator Tankless Water Heater Service Valve Kit with Pressure Relief Valve, Clean Brass, 3/4 Inch Service Installation Valve for rheem,rinai,ecosmart,navien,noritz,takagi,bosch. Products with electrical plugs are designed for use in the US. If you'd like to support the site, please allow ads. Now that weve reviewed everything you should know about a water heater pressure relief valve you might have realized that you need to replace your water heater valve. exhaust pipe for a clean installation look in location where 3/4 lead free isolation valves with relief valve designed to work on NPE, NPE-2, NPN, NCB-E and NCB-H series units. We asked for this to be added and the sellers told us that per the codes for tank-less hot water heaters (California) a pressure relief valve nor a discharge line are needed. Yes, water hammer spikes with rapid turn-off can easily exceed 150 psi on a static 50 psi system. Space-saving high-efficiency condensing boilers provide the ultimate heating and comfort experience. What does it mean when a gas appliance (water heater, furnace, or range) has been "red tagged"? Without a neutralizer, condensate has the potential to corrode a buildings foundation, floors, and drainage system. Enjoy an endless supply of hot water with the SENSEI RU160iN Super High Efficiency Plus condensing tankless water heater from Rinnai. The Navien NPE-A is a powerful tankless water heater that delivers hot water on demand. Does a water heater need a shut-off valve? But what would be the value added by a pump that I cannot get with gravity alone in this case? Due to inclement weather across the U.S., packages may be delayed. If there is an excess of pressure in the heater and a lack of air in the expansion tank, the water will be forced back into the expansion tank instead of the main water supply line. Hi, my 7 yr old Navien tankless water heater has been intermittently spraying water from pressure relief valve every day or so. There is also one further complication to this . To do this, connect a garden hose to the drain valve located at the bottom of the water heater. rack system allowing up to 16 units on a free What is the difference between a regular water heater and a direct vent water heater? Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Where do I add window casing with a replacement window. Make sure you report which pressure valve went off the direct hot water should be 150psi. When doing this, just make sure that the new relief valve youre buying is compatible with your water heater and rated for 150 PSI and 210 F. Propane Gas 1.30 0.08 W.C 3.86 0.08 W.C gas valve Proportional valve Air Pressure Minimum Modulating Gas Pressure PCB Board Manometer Maximum Modulating gas . It may not display this or other websites correctly. They always have relief valves. Now, pull the metal lever of the valve slightly, so that a small amount of the watera quarter cup or sodischarges into the bucket. With the crazy weather maybe something odd is occuring. Protect your water supply and your water heating equipment with eco-friendly water treatment solutions. Why can I no longer turn the knob of my self-locking door from the inside? Removing the old valve and installing the new valve is a relatively simple process. Here is an excerpt from a Tagaki installation manual: Interesting since the regular tank models have expansion tanks on the cold side. Make sure your condensate doesn't come into contact with metals. I am currently monitoring my water pressure for my house with a pressure gauge. Use with Pipe Cover. Includes an add-on PCB, 1 push button and wall plate. Close the isolation valves to the cold-supply and recirculation lines. So how do you diagnose this issue? Colored valve handles for easy identification and use of hot and cold valves. Sound may come out of the recirculation pump. Most standard indoor water heaters have a relief valve. Everything is good, I installed the proper intake an exhaust with 3in schedule 40 PVC pipes as recommended, I plumbed 3/4in copper pipes for cold and hot water, a 3/4in gas line. This innovative Navien recirculation valve allows you to recirculate hot water through existing lines. We have fast FREE SHIPPING on all orders over $99 and ship all orders within 1 business day. Approved for indoor and outdoor installations. Most standard indoor water heaters have a relief valve. Fortunately, by understanding how relief valves work, you can solve whatever problem youre having with the one on your water heater. 132. Then, take a bucket and put it under the discharge tube. So if youre having any issues with the valve, youll have to call a professional to have it fixed. The NPE-2 series offers ultra-high efficiency up to 0.96 UEF to keep your utility bills low, endless hot water, and exclusive ComfortFlow technology with a built-in recirculation pump and buffer tank. Lead-Free isolation valve kit with relief valve 3 valve set: Cold, Hot, Recirculation Return. They are making a come back, they were popular in commercial high rises once upon a time, but dropped because they were less efficient and more troublesome. 3/4 lead free isolation valves with relief valve designed Kelaro Tankless Water Heater Flushing Kit - Just add Vinegar Descaler, Hourleey 3/4 Inch IPS Isolator Tankless Water Heater Service Valve Kit, with Pressure Relief Valve, Clean Brass, 1996-2023, Amazon.com, Inc. or its affiliates. Please try again later. The pressure relief safety or p/t valve can open due to abnormal conditions such as too hot, or too much pressure, or just bad. 1 year warranty from date of purchase. Residential condensate neutralizer for NPE-2, NCB-H, NFC-H, NHB and NFB-H units designed to neutralize the condensate of one unit. However, if it continues to stick, then youll need to replace it. Why should a tankless water heater have an isolator/service valve kit installed? Visit ourWATER HEATERSpage for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles. through the internal PCB. I have a 3 year old Navien 240a tankless water heater. NaviCirc Valve Kit includes the NaviCirc Valve (PFFW-SXX-001) and two 1/2" x 3/8" flexible hoses and adapters. This Navien Combination Water Heater / Heating Boiler can be vented with . Replacement Media for Light Commercial Neutralizer. The water heater pressure relief valve is in place so that it can relieve excess pressure and temperature in a water heater if either of these is too high. However, being tankless does not mean they will not leak. The drain lines in my house are copper and then they become cast iron at some point (who knows what is original from the 70's and what has been remodeled before I bought it). Im starting to see these more frequently, usually coupled up with a holding tank and a high velocity heating system. Does a tankless gas water heater still work with no electricity during a power outage? Is the minimum size water heater inlet pipe 1/2" or 3/4" according to the building code? This does not need a TPR valve right? . Water Heater Navien NR-180 (A) Owner's Operation Manual. We might be able to do something about it. Ideally you would be able to pipe it somewhere where there isn't any metal piping but if that's not an option you can use a condensate pump to, pump outside if you're in a climate where you don't experience freezing temperatures. In my case, water was coming out from the pressure relief pipe. >>. What's that powdery crust on the pipe connections at the water heater? Every major brand of tankless requires a drain pan if the unit is installed where a leak can cause damage to the home or building. Lead free isolation valves. Basically it comes out to about eight pounds of water for one therm or a hundred thousand BTUs or a hundred cubic feet of natural gas. Can the temperature and pressure relief (TPR) valve discharge pipe for a mobile/manufactured home water heater terminate under the home? 99. or do all tankless need them? However where am I going to drain the neutralized water? 1" isolation valves without relief valve designed to work on NHB, NCB-E, NCB-H and NFC-H series units. If its closed, then the valve wont be able to relieve the heat or pressure that builds up in the closed water heater system. When was a gas water heater first required to be elevated 18 inches above a garage floor? Can I run a plumbing vent through a wall instead of the roof? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. The manufacturers typically only require a pressure relief valve, not the combination temperature and pressure relief valve that is necessary for tank-type water heaters. Where do I find the water heater in a mobile home? Base rack allows installation for up to 2 units back to back. Manufactured in United States. expand the base rack system allowing up to 16 units back Condensing tankless heaters use a dual heat exchanger design to make maximum use of the energy delivered to the system. $5799. Why do water heaters have a sacrificial anode? Unprotected NM-cable connected to water heater. All Navien Valves are brand new in the original factory packaging and are guaranteed to fit and function properly. Navien Plumb Easy Valves (V2) are designed to provide ease of installation and operation as well as for quick maintenance on all tankless water heater models featuring a compact, versatile design that is easy to use. I replaced it with a tank-less gas heater. A structural engineer we used to work with in the Florida Keys, Paul Mitchell, suggested to us after a struggle with a county inspector at our jobsite that Never argue with an inspector. I must be missing something obvious :(. You cant replace or remove it. NPN series parts kit designed to help service in the field. Water is life. I see. Range 100 to 180 Degrees F, Seat Material PTFE, Handle Material Vinyl Covered Steel, Seal Material PTFE, Includes Includes a residential pressure relief valve . Remove the valve and discharge tube. Worth watching for sure. Gas-fired tankless systems can be designated as either condensing or non-condensing. Condensing tankless water heaters can achieve efficiencies of up to 98%, while non-condensing water heaters have a maximum efficiency of about 80%. This is the case with tankless water heaters installed with a recirculation loop and a storage tank. Navien OEM Repair Parts and Tankless Water Heaters. W5 investigates cases where brand-new HVAC systems aren't working properly, with some homeowners finding that their homes are freezing on one floor and feeling tropical on another. Why do water heaters have a sacrificial anode? Ensure that all lines and valves are joined correctly, and you set the relief valve during installation according to the size of the heater. Code requirements cited may have been changed in a newer code edition, or may not yet be adopted in your area. 1. Noritz Isolation Valve Naviens NFB primary manifold kits are system matched for fast installations and maximum efficiency. There but if we come down here. If youve been noticing any issues with your water heater pressure relief valve, then you need to know where it is on your water heater. Outlets and voltage differ internationally and this product may require an adapter or converter for use in your destination. Efficient, durable and high-performance products for any commercial application. Thanks for contributing an answer to Home Improvement Stack Exchange! Your question might be answered by sellers, manufacturers, or customers who bought this product. So I would say not ALL need such a valuebut I can only speak for the models (SETS) units. But you might want to get the pressure valve fixed if its leaking. What is the usual maximum load for drywall? Check our price for ateam inspection by two FL-licensed contractors and inspectors. The more efficient the unit is, the less energy waste which translates to more energy savings. Pump not included. In most cases, the issue may be remedied by opening and closing the pressure relief valve that is located close to the exit of the heater. Another reason the valve could be leaking is that there is sediment or dirt trapped inside the relief port. Heres 9 Reasons Why! Replace the old valve and discharge tube with new ones. 5 Reasons Why Tankless Water Heater is Leaking 3. When the heater starts heating water after some hot water is used up, some excess hot water flows back into the main inlet pipe as it expands, causing the water pressure in the pipelines to rise as it has nowhere to go. Required for outdoor installations. Navien Water heaters have an advantage when it comes to being energy efficient. Bad Installation. Why Does My Shower Have Too Much Water Pressure? NCB and NCB-E series parts kit designed to help service in the field. 3-year warranty from date of purchase. servicing of DHW systems. Why are trials on "Law & Order" in the New York Supreme Court? Installed Navien CH-210 last summer (2013), has worked fine until late December when heating relief valve (Watts 3/4", 30psi) began to intermittingly "pop". << What is the difference between a UL rating for dry, damp, and wet locations? Note: The pressure relief valve on a water heater cannot be used as the device to control the pressure. . If the increase in pressure is constant, like in the first pressure test, then you need to install a new pressure regulator. Once the pressure has reached the blowdown amount, the pressure relief valve will close again so that you can use the water heater as intended. Natural Gas Tankless water heater condensate volume. What is required clearance for access and working space in front of an electric water heater? Does a tankless water heater need a condensate neutralizer? Sometimes, the relief valve isnt installed correctly, or the seal or other parts are failing with time, causing the relief valve to begin dripping. for ateam inspection by two FL-licensed contractors and inspectors. Not sure why they are coming back now, except maybe everyone forgot? Pumps and Tanks Well Forum & Blog. NFC-H series parts kit designed to help service in the field. Replacement Media for Commercial Neutralizer. If your pressure relief valve is leaking, then this maybe because it isnt seated properly in the tanks threaded opening. The tankless water heater should have been installed only by a qualified, Tagaki approved installer so it should be proper. Watts 556034 3/4 inch 150# Pressure Relief Valve 0556034. Position. Connect and share knowledge within a single location that is structured and easy to search. Everything has been done according to standards that have been mandated by plumbing codes. Pipe cover designed to hide gas, water and Buying a home in North/Central Florida? Most technician said there might be a leak in the heat exchanger. The free standing rack system is For reference, the normal pressure of the water inside of the water heater tank is 50-100 PSI. CH series parts kit designed to help service in the field. Navien units have UEF ratings of up to 0.96 while Rinnai Units max out at approximately 0.93. To stop the humming noise, you must fix those issues. Are electric tankless water heaters condensing? Are water heaters required to be raised off the floor? Please make sure that you are posting in the form of a question. Whether or not a tankless water heater is required to have a pressure relief valve depends on what the manufacturer states in the installation manual. Installation of Liquid Propane Gas line to new Takagi Tankless Water Heater, Correcting Navien Tankless Hot Water Heater Installation. If its the case, you should change your hot water heater temperature. Does Counterspell prevent from any further spells being cast on a given turn? The drain system of the house will eventually be "the same pipe" as there is only one connection to the public sewer line. Skip to content. Therefore, a device, such as a thermal expansion tank, must be provided to control the potential pressure increase. Condensing combi-boilers deliver high-efficiency endless hot water and space heating in one compact unit. Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater. Step 3: Drain about 10 gallons from the water heater. Is it a bug? What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? A condensate line that goes out would be tens of feet long and I would have to tear down half of the house to run it :(, Tankless water heater plumbing: neutralized condensate and pressure relief valve, https://www.diversitech.com/en-US/item/id/11672, https://www.google.com/aclk?sa=L&ai=DChcSEwjZsrDb78zgAhUOtrMKHQFmBB8YABAIGgJxbg&sig=AOD64_3f3Fc_0mYzjmXXWbHAYQvAGUPvyw&ctype=5&q=&ved=2ahUKEwiJ5abb78zgAhWCZd8KHSvbAk0Qwg96BAgLEBA&adurl=, We've added a "Necessary cookies only" option to the cookie consent popup, Tankless water heater - not consistent hot water output. In some locations neutralizers are a code requirement to protect the environment and municipal waste systems but it's rarely enforced. and NHB (NHB -110 & NHB-150 models) series units produced on or after September 15, 2016. Part Number: (GXXX001931) 75 PSI . what pressure rated boiler relief valve should be used on a boiler rated for 500,000 btu supplied heat to 3 story structure. Tankless Water Heater Service Valve, Pipe Size 3/4 in, Body Material Brass, Pressure Range 398 to 500 psi, Temp. The Titan tankless water heater in the picture at the top of the page was in a homeowner-remodeled house we inspected today, and is the inspiration for this article. Navien Water heaters have an advantage when it comes to being energy efficient. But if its more than 80 PSI, then youve got a problem. Some people don't really understand the function of a pressure relief valve on water . When either of these takes place, the relief valve is activated, and the excess hot water flows out the relief valve. Base. 2023 TanklessParts.com ALL RIGHTS RESERVED, Navien OEM Repair Parts and Tankless Water Heaters, Navien OEM Repair Parts - Shop by Part Type, Watts 121327 3/4 inch 100# Pressure Relief Valve 0121327, Watts 556034 3/4 inch 150# Pressure Relief Valve 0556034, Navien 30002729A Pressure Reducing Valve Kit, Navien 30005993C Auto Feed Valve Assembly, Navien 30008245A Water Adjustment Valve for NPE/A.

The Ben Show Racist Football Coach, Terri Pearsons Net Worth, Header Collector Flange Reducer, Who Is Emily From Bible Adventure, Accident On 364 St Charles Today, Articles N