Water heaters in general and because it’s right here you may have questions about it what kind of advantages and let at thermostatic mixing valve give the water heater in the customer well you have several advantages to a thermostatic mixing valve one is it prevents scalding we’ve recently had some codes go through a si SSE 1070 saying that the thermostat shouldn’t be the only temperature limiting device on the watery right stuff can go wrong elements to ground which we’ll talk about later thermostats could stick and that could potentially cause you to be burned because the water is going to become scalding so with a mixing valve it’ll prevent that because it only at a premix the water.
We only have say in this case 120 degree water coming out no matter how hot the tank is right another advantage of a mixing valve is is this you can increase the temperature of the water heater and pretty much make your water heater feel bigger in some cases about 30% bigger and so you could get a lot more hot water because you would draw less hot water off the tank because the storage temperature is so high and use more cold water to get the temperature you typically take a shower with and so it could make a smaller water heater feel bigger yeah that’s that’s a great advantage because you would you’d use less hot water because the water is a lot hotter they’ll use less of that and add more cold water to mix it down so that’s a that’s a great feature now we are we actually recommend is point-of-use mixing valves at each point of use you know each hot water faucet this is this is an example of a whole-house mixing valve correct.
Another thing on this installation we have a thermal expansion tank and we can’t talk about installation without thermal expansion tanks if we recommend them they’re highly recommended because especially on a closed water system yeah really actually if you read the manual the warranty with the water heater if you’re on a closed water system for the warranty a plot to apply you have to have a properly installed properly pre-charged expansion tank which is very important yes a lot of people install them but they don’t preach all yeah that’s my next thing that’s one of the biggest mistakes that somebody will make especially di wires they’ll install the thermal expansion tank think they’re doing you know doing well you know I did it all right and end up having the same problem still having thermal expansion because they didn’t pre-charge the the thermal expansion tank with air and let’s talk about that how would we do that the correct way well the correct way to charge an expansion take and this is very important you have to check your water pressure first right you want to check your water pressure.
We typically recommend over a 24-hour period and let me have an example of a water pressure gage of a water pressure gage right here this one has a lazy hand and why that’s important is this your water pressure typically is going to fluctuate some and so the way this works you have a black hand that turns up the dial and it carries the red hand along with it but what happens is the black can gives you your actual static pressure right current water pressure right then but at its highest point it’s gonna carry the red-handle long with it and even if the black can’t drops the red hands gonna stay where it is so it’s gonna show us our highest pressure it’s gonna show the highest pressure which is very important and the reason why that’s very important is this typically this is not something that’s strictly enforced at the time typically water pressure should never exceed about 80 psi okay we actually recommend in a house or residential home for your water pressure to be somewhere between 50 and 60 psi okay if your water pressure exceeds 80 psi we typically recommend that you stall a pressure reducing valve which lowers the water pressure and set it somewhere between 50 and 60 psi okay now to hold that pressure steady yes okay which would cause your tank to live longer to cause your toilet valves and your ice makers and all this plumbing stuff in your home to last longer but that’s just typically what we recommend okay and then we’re going to set our pressure on our thermal expansion tank to whatever pressure are our incoming water pressure is right correct say.
We have 53 psi of water pressure right it stays at 53 all the time it’s 53 before we ever install the thermal expansion tank on the cold water line we’d fill it full of 50 53 psi of air needs to match exactly what your water pressure is because if it doesn’t say you don’t have enough air in it or in the instance you have too much air in it it’s gonna act like you do not like you don’t even have it yeah it’s not doing anything at all yeah not enough air it’s just gonna press the bladder all the way to the top and not give you anywhere to absorb that additional volume of water or if the too much air in it it’s not even gonna move the Blatt okay and so it’s very important that you properly install the expansion tank yes so you got to do all of this before you install it before we put it on our water line we’re going to pre charge that that the air into our thermal expansion tank and then we’re gonna go ahead and put it on so it can work properly so it’s just a couple things that we want to keep in mind whenever you’re working on water heaters out in the field you might want to check the the pressure of the thermal expansion tank if they’re experiencing thermal expansion.
Because it may have not been you know installed correctly okay so let’s go ahead and get with this water heater let’s talk about you know that’s a little bit about the install of of an electric water heater now how the water heater works let’s let’s go ahead and talk about that and and let’s let’s talk a little bit of the sequence of operation how this water heater works and how power flows through this water heater alright the way a typical electric water heater works is this you install the water heater you have a complete cold tank of water the upper element and upper thermostat comes on first so the upper thermostat powers the upper element okay alright and then once it satisfies this top 20% of the tank for temperature the thermostat transfers power down to the bottom thermostat which powers the lower element and it hates the other 80% of the tank okay so that’s on a cold tank of water cold tank so you’ve got a cold tank just installed it the first thing that’s gonna happen is this upper thermostat and heating element are gonna energize gonna heat up the top 20% until that thermostat satisfies correct whatever temperature you have set for which is 120 is what we recommend they’re factory preset at 120.
Then we’re gonna throw power down to the lower thermostat and heating element and it’s going to heat the rest of the tank up until it comes in it comes up to temperature and then the unit will go into standby now now the water heaters hot now what happens when they start drawing water off a hot tank well say I have a hot tank of water sitting there ready for me to use and I go to take a shower all right cold water is gonna enter the tank through the cold water connection it’s gonna enter through the dip tube and dump into the bottom of the heater okay and cold water is gonna push the hot water out well if you think about that the cold water is going to come in and dump to the bottom that’s going to cool the lower portion of the tank which is going to cause the lower thermostat to power the lower element and it’s going to come on okay and then you know you take a shower you’re gonna use several gallons of hot water but unless you drain this water here completely of hot water the upper element thermostat may never power back up to kick on okay usually your lower element and lower thermostat or the workhorse and they heat most of the water yeah and if anything was to fail usually first is that lower element yes just like with anything if you have a part that works a lot usually the part that works the most it’s typically the one that’s going to fail the most because of usage yeah and I want to kind of go back to the cold tank.