We need to do is we need to fire the burners and what it’ll do is stage fire the burners just one or two burners here and there to keep this heat exchanger warm it’s pretty ingenious how it works so the problem with the heat exchanger with failure is not so much thermal cycling like it is with maybe furnaces it’s more buildup of scaling yeah buildup of scaling and heat exchangers I mean there’s a 10 year warranty on most the heat exchange of these 10 or 12 typically a heat exchanger under standard load conditions which is domestic our domestic hot water typical usage should last 25 to 30 years but again the beauty of these is it’s a component system anything that goes wrong inside here can be replaced with a Phillips head screwdriver and that’s the beauty of it if something something goes out the heat exchanger starts to develop a leak in about 25 minutes a good technician can have this heat exchanger out of here well have a new one in mmm-hmm pop it in so easy so this is the the exhaust fan that’s the combustion fan that’s correct and on it on an indoor unit typically you’re going to see a black boot right here and that boot is connected to the the combustion intake.
which is this part right here that we saw and then the exhaust of course is pushing the exhaust out the inside pipe on an outdoor unit of course you don’t have to have all that because all we’ve got is the one slit right is the intake and exhaust are there any standard venting dimensions like distance from a window the inspector can be aware of when looking at an outside unit yes and the word to the wise there is an inspector should have the book for the unit because again every unit is different mm-hmm and every tankless water heater manufacturer sets its own standards for vent clearances two different things typically we don’t have the manual so we just have to give it our best shot so you know if we have a manual handy handy it’s it’s a good it’s good to look at but if you just had to stand back and look are there anything any dimensions that are common to all these things Oh old tankless water heaters like distance from a window just since above the ground typically twelve inches above the ground is what what you’re looking for for the vent if it’s outs if it’s an outdoor unit you really generally don’t have that issue because the unit’s gonna be at least this is you know 24 inches high plus the pipe cover on the bottom so it’s usually typically thirty inches above the ground where event is about this high in cement about this area house well plus the the pipe cover box is underneath it so it’s usually about thirty inches off the ground so it’s not a problem but where we’ve got to come out through a rim joist run into situations where a rim joist is not 12 inches off the ground and you see the the vent pipe coming out.
We know it’s too low you can just look at it and tell if it’s less than twelve inches above the ground it snows going to cover that thing up yeah and what it does it’s going to cause problems for the venting typically Rinnai for example is one foot from an opening door or window or any kind of intake power intake it’s four feet can’t be right directly below a deck you can’t be right next to a door mm-hmm there there are some typical things that you can look for clearances figure on a foot though at least for just about every unit for the vent clearance to and opening into the house from grade no open opening it yeah like a window or door anything like that figure at least a foot the other thing to look for the other red flag for inspector there are a few of them condensing units air conditioning condensing is we typically don’t want to see exhaust gas blowing right on a condensing unit why because it’s pulling you know somebody could be taking a shower it could be pulling that exhaust gas in over the condensing coils exhaust gas has sulfur dioxide carbon monoxide and water vapor those are the three basic elements of exhaust gas well what happens when you put sulfur dioxide and water together gets sulfuric acid okay so you don’t want that running across an air-conditioning coil you want it typically at least six feet away from a gas meter because this is an power in tech you don’t want to be pulling raw gas into this unit not a pretty sight you typically want to be not directly below an electric panel and have some distance away if you can off to the side of an electric panel so these are some of them for the same reason is because of corrosive gases mm-hmm exactly.
You don’t want that going up into the breakers well is there anything let’s see this the controls here we’d see inside we wouldn’t see those outside correct yep and the control is a digital control and it does have a program button where whereby we can find out a lot of things about the inn if there if it has ever shut off on any code again what the computer does is it regulates the system if for example someone were to shut the gas off to this unit a code 12 would flash here the homeowner would come down and see it’s flashing at 12:00 and call hopefully the technician to put it in and say splashing a code 12 well that means that it doesn’t have gas some reason someone has shut it off or the the vent is blocked it could be a code 10 or a code 12 actually some of the codes overlap but you by pushing the program button we can find out what the codes are we also with this unit we can find out what the flow through the unit is at any given time by pushing a series of buttons on that controller now everyone’s going to be different so there’s no sense I’m really showing you this particular unit but there’s a lot that you can find out from that control other than just the output set point temperature at least at least we know that it’s possible via information from the display witness remembers amount of information from that which comes straight off the computer um do inspectors need to worry about insects yes yes yeah that’s a typical problem you don’t find it on outdoor units I know it sounds strange but we really don’t find problems with insects on unit because they run they run enough to blast any insects out of there well.
I just think that insects stay away from them yeah because of this little slit that’s like a metal vent with this this vent because it’s pulling in through a plastic and this is cool to the touch you know insects might be walking around on this thing you’re not gonna walk around this cuz it’s hot yeah especially when the in is well only when the unit’s running but it is hot you know this is where the heat is we see these typically pulling in Miller moths bees I mean I’ve seen situations where we had pretty much every species of bee inside of that combustion thing because that’s what it’ll do is it’ll suck it right in the combustion fan that combustion fan will start to be noisy so if an inspector sees one of these that’s noisy almost always what the problem is there’s int there insects lodged in that combustion fan and it’s getting it out of balance so I suppose the same thing could happen with seed pods from oh sure from surrounding trees that sort of thing and then a restriction any kind of restriction cottonwood mm-hmm you know that can as long if it’s sucking way too much.
I mean generally speaking it will suck it into the burner system and the burner system will burn anything that comes in there if it’s small enough a particle if it’s not if it’s like a bee or an ant or something like that it’s gonna get lodged in here it’s not gonna make it to the burners and then it’ll start making a rattling sound or something like yeah well it’s going to whine that’s gonna make a whining sound Dave can you talk a little bit about the differences between a conventional water heater and a tankless water heater sure tank type water heater has some amount of storage 40 50 60 up to a hundred gallons of storage and what’s happening on the tank type water heater is that water is being heated all the time 24/7 which is why people are going to tankless water heaters because of the energy savings primarily the space savings the lack of maintenance of having to schlep a water heater up out of the basement every five or six years lack of sedimentation that we talked about and primarily the lack of running out of hot water which is what you see typically with tank type water heater with a tankless water heater it’s impossible to run out of hot water it’s impossible to ever be in a situation.