Monthly Archive: October 2017

Electric Water Heater Inspection

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.