When do you need an Expansion Tank?

hey guys it's Brian we're here in Spring Valley we're going to be replacing a water heater a customer of mine that I've done some other work for as has said that his water heater has failed and he's picked up a new one already himself under warranty because his old ale Smith water heater was under warranty this is the old one I had replaced the TMP on this water heater just just a few months ago because it was bleeding and leaking in I had recommended to him at that time that he needed a that he possibly would need a thermal expansion tank you know I'm gonna go over reasons why why you need an expansion tank in this video but but anyway he just replaced the TMP at that time and later on a few months later here now his water heater started leaking so he says I just I just got here I don't see any water on the ground here but he's a water heater started leaking so we're gonna be replacing this water heater and we're going to be adding a expansion tank and and I will go over also when it is that you actually need to install an expansion tank so the first thing that we need to do when we're replacing the water heater is we need to drain it so if you look up here we got the cold water shut off you know which supplies the whole hot side of the house with hot water so we have that shut off and and then we hooked up a garden hose to the drain port and we opened up the drain and you see out here we are draining out the water heater so you can see there's water heater I think he was draining it yesterday and so I think it's mostly drained we'll undo the straps and and check the weight on it but I think it might already be drained because he said he was going to drain it yesterday screw this screw right here these screws and those screws right there we'll just pull out a little branch section out set that off to the side now you got a disconnect your gasps gasps ah the shutoff so does the water heater feel emptier that feel like is pouring water so he drained the water heater already which is good saves us a little bit of time these smell that dead rat on the road there's a dead smoosh trout on the road over here come show me the dead rat but I can smell it from here [Music] I always add a little bit of flux just to help with the with us with this order okay so if it doesn't want to stick anywhere right there you know the map gas boy yeah I'm gonna get it the copper a little bit but I don't want to unsplit it up there fitting and you see how it's starting to break free that's when I want to take my heat away because if I get it too hot I burn it up and it'll never come off [Music] [Music] oh yeah mama my squirt bottle is empty right now [Music] okay we're all wrapped up got the new water heater in got the new expansion take in you can see that and on the Gauss line we went ahead and added a drip leg on the gas line had to repipe the the temperature and pressure-relief line here you know water heater out on the top no big deal we piped it down on them on the side here so that's pretty much it it is all wrapped up now you can see on the expansion tank here the cold water comes in from here and we run a tee off the expansion tanking expansion tank should be between the cold water valve and the water heater itself okay and the purpose of an expansion tank is to is to absorb any thermal expansion that's occurring from the water heater okay so when do you need an expansion tank you need an expansion tank when your city pressure has the potential to be higher than your temperature and pressure-relief valve the temperature and pressure-relief valve has a rating on it and for residential that pressure rating is always a hundred and fifty pounds okay so if the city pressure doesn't matter if you have a pressure regulator regulating down your house pressure or not if the city pressure gets higher than a hundred and fifty pounds okay then when this thing is is expanding due to temperature you know you have a thermal expansion occurring in the water heater that expansion normally goes out into the city main if that pressure is higher than this rating then it doesn't go out into the city main and this thing starts to open up and leak water out of it okay so that's an indication if you have an intermittent leaking temperature pressure relief valve that's an indication that you potentially have a thermal expansion issue and that you might need a thermal expansion take installed what the expansion tank does is it has an air bladder in there okay they're pre charges when it's charged up 20 pounds it has an air bladder in there and it works as a cushion so when this thing builds up pressure it absorbs additional pressure here through the air bladder okay and and you know so if there's resistance from the from the city main this will absorb it the other time that you need an expansion tank is when you have a check valve in this system and in a residential application the only time you would really have a check valve in the system is if you're running a hot water recirculation line so you'd have cold water coming into the water heater and then you have the hot water going out and then now hot water return line coming back well that runs on a pump and that would end up pumping back through the cold water line and you end up putting a check valve in there so that you don't pump hot water in the cold water line well that check valve does interrupt the ability for thermal expansion to bypass back out into the city main so if there's a check valve installed at your house you absolutely have to have an expansion tank if the city pressure outside of your house is or has the potential to get higher than the rating plate of your T&P valve which is most often 150 pounds you have to have an expansion tank okay that's pretty much it those are the two main reasons you need an expansion tank so thank you see you on the next one you

Channel: Wroolie Mechanical

Views: 591,767

Keywords: Expansion Tank, water heater replacement, how to install an expansion tank, how to install a water heater, soldering, plumbing, water heater expansion tank

Id: _STLqrY3x0A

Length: 11min 18sec (678 seconds)

Published: Mon Sep 18 2017