✅ Expansion Tank Installation on a Water Heater - What is an Expansion Tank? - How to Install it

hi guys how are you doing it's dennis here today's video is going to be about expansion tanks uh what they are what they do when you need one and how you can install one uh the most common expansion thing size is this 2.1 gallon so we can just call it a 2 gallon tank and then if you have a larger home that has a 75 or 100 gallon tank most likely you have or you need a 4.5 gallon one now when is one needed by law you need to have an expansion tank when your home has a backflow preventer of the water main uh entering the house or a check valve throughout the plumbing system for example if you have a water heater with a circulation pump then you surely have a check valve and then this is required by law every time you heat something expands in volume including water when you hit the water in the tank it expands in volume and under some circumstances because of the water expansion you can get a uh accidental water discharge through this temperature and pressure relief valve although this is not what this valve is supposed to do so if you get constant drips through the end of the pressure relief line or maybe uh water gushing out of it most likely you have a problem with an expansion tank and you will need one installed but i'll tell you about that further in this video um well let me get get back to the tank so uh what you see here is is a metal metal tank that has a rubber ball inside the tank so basically it's like a rubber ball in fact when you put your finger through you can feel it uh there's a rubber membrane here that's pressurized um these come already pressurized from the manufacturer but they only pressure at either to 20 or 40 psi so manufacturers pre-pressurize them to 20 others do uh pre-pressurize them to 40. uh in this specific case this brand name pressurized them to 40 psi and the important thing here is before you install one you need to go ahead and check the water pressure in your plumbing the best place to do that is right after the main valve for the house so this is where the the water enters the house you have a ball valve so we will put this pressure gauge so we have about 80 80 psi so that means we need to pressurize the expansion tank to 80 psi all right let's go back to the water heater so that's a small two gallon tank that's the four and a half gallon tank and right here the parts i will need so you will need a three-quarter brass tee six inch or six to eight inch long uh three-quarter brass nipple a 90 degree elbow a brass elbow and also a shorter nipple anything between inch and a half to two and a half inches is good and i recommend that you use the brass fittings do not use galvanize it's not worth it um you will be saving just about a dollar or two per piece but the galvanize is not good it rests and it will leak very very soon so use brass fittings we will need a teflon tape blue teflon tape pliers i don't think we will need a screwdriver here and in this video i will show you uh how to source the parts through amazon i will include links down below in the description for all the parts that i'm using today stay with me uh through this video and you will be able to install one yourself so very first thing we will do is turn off the water to the water heater then i already have my holes attached here just make sure it's straight all the way down the driveway and then you'll come back here and open the drain valve so we like to release the pressure out of the tank so we can go ahead and disconnect the um the water flex here on the cold side in you need to install this on the cold side do not put it on the hot side uh it does work but there's problems uh being on the hot side it's better if you start on the cold side so but before i disconnect this uh i will actually get my fittings ready here this is what we're gonna do i'll pay attention to this um short fitting that will go on top of the of the tee and where the uh water flex will screw on as you see the end of the fitting is quite sharp don't use it this sharp because it will cut through um the rubber ring of your supply line and it can cause leaks so what i do is the following i go down to the um to the curb here and i use this concrete curve to flatten out the surface of the nipple to make sure that it doesn't cut to the rubber seal of the supply line let's see this is good see no more no more sharp edges and on top of that i'll use my file to make the surface even more smoother this is perfect i'm confident there will be no problems with the supply line it has happened alright so you get your blue tape and you wrap it around the thread that is going to thread in the t okay that much is enough so you go about let's see how many times one two three four times it's about four times enough and then i still go over it like this put some pressure on top of it um so you shouldn't be putting too much because if you put too much then it doesn't work it just kicks it out uh you should put just enough so all the blue tape stays within the the connection um and you should be able to see and feel the the ribbons of the of the thread all right we've got everything here and now i'm ready to disconnect the water supply now i had this uh drain valve open because that will make sure i don't get water spill here but you don't also want to drain the whole water heater out just for this as soon as you ensure there's no water leaking up there you can stop the the drain valve you don't really have to drain all your water out and if you notice i didn't even shut off the water heater the gas supply is still on the the burner is engaged it's not heating but you don't really have to turn it off so all right we had a little accident uh we had a little accident the water is coming back somehow so i will uh actually go ahead and turn off the water uh to the house completely so we run into we run into surprises of this sort i wasn't expecting that all right now we should be good now make sure you shut off the water to the house completely so you don't get surprises of this sort let's see what's going on all right this is better this is better i'm shutting off the the drain valve and now what we're going to do is we will wrap around the blue teflon tape monster tape right around here so so so all right that's about right this is how much you need and to be on the safe side i'll put some teflon ptf e teflon tape on top of it just make sure it's screwing on smoothly all right the tea is going on i'll remove this from here as it is no longer needed so [Music] all right like this let's put the short nipple uh all right the long nipple so [Music] so so in plumbing nothing is about being you know too tight it's about being right so if you prepare your connections right you don't have to tighten too strong just enough here we go to get a tight seal it's not about strength all right it's a little like this pointing upwards now it's time for the expansion thing but remember we need to pressurize it uh the pressure in the house is 80. so i will be using this uh compressor that i bought from amazon and i will be including a link for it in the description below um it's a very nice one because you can either plug it into your uh cigarette a lighter outlet in your car or you can plug it in the 110 volt uh power outlet in your home so in this case i'll be using the 110 volt outlet let me go around here and with those new and fancy compressors you actually um set the desired pressure ahead of time like this we want 80 actually i will go like 82. i always recommend going a little bit higher so at 82 i'll connect the the holes right here to the stem and then you just hit ac and it starts pressurizing see the the existing pressure in the thing was about 45 and that's because it's hot outside they pressurize them to 40 psi and some other manufacturers pressurize into 20 psi all right let's wait a little bit right here we go 82 and it stopped by itself very smart i really like this compressor all right i've got the tank uh pressurized i just need to put some teflon tape on it and we're ready to place it on top of the water heater when you use this uh ptf teflon tape ptfe to be exact make sure you never put it inside the pipe always on the thread on the outside it doesn't have to go inside it will clog your faucets the aerators of your faucets all right let's see i'll actually do a little tree here that flex line is kind of on my way and i'll take the opportunity before i put the expansion tank to screw on the flex on top of this nipple if you use uh hard pipes like brass nipples you don't really have to support it to the wall anyway it's not that heavy it's actually empty there's no water inside so it's not supposed to store water if it's heavy and there's water inside it's broken so uh as i said there's a there's a um rubber membrane that does the trick and it doesn't last forever pretty much every time you replace a water heater and you have an existing tank you have to replace the tank as well i've seen many jobs where plumbers would replace the water heater but they would ignore the expansion thing they just don't want to bother with it you know cheap plumbers so you have to have it replaced with every water heater when you have one and if you don't have one this is how you can install it uh now we're all done i'll go ahead and turn on the water to the house [Music] and i'll crack this water valve open always do it slowly guys pressurize the system slowly okay it's looking good this homeowner here should be good for another 10 to 12 years he just got a new water heater installed now the expansion tank uh if you guys like to do this job yourself at home please check the links down below you'll find the links to amazon where you can purchase all the parts and materials needed for this job uh thank you for watching and i'll see you on the next one bye you

Channel: Dennis The Plumber

Views: 622,418

Keywords: expansion tank installation, how to replace expansion tank, thermal expansion tanks explained, what expansion tanks do, fix high pressure with expansion tank, expansion tank hot water heater, how do expansion tanks work, expansion tank sizing, expansion tank plumbing, expansion tank pressure, when do you need an expansion tank?, expansion tank, thermal expansion tank

Id: P9iQxYQc2J0

Length: 19min 59sec (1199 seconds)

Published: Thu Apr 29 2021