How to Properly Inspect a Water Heater

Where you’re not getting hot water out  of the system if it’s working properly  but what we do have is a certain amount  of hot water that’s available per minute  or flow that’s available from the  tankless water heater and let’s face it  you have a burner system that can only  heat the water so fast right so a  typical home when a home inspector needs  to look for to size to make sure that  the water the tankless water heater is  sized properly was how many fixtures are  in the house and what what is the  maximum flow that that household could  be using at any given moment and what we  typically like to do is match that flow  up to that demand if we can you can’t  always do that and sometimes owners a  buyers need to understand that they may  not be able to turn everything in that  house on and get flow out of all those  fixtures so can an inspector test that  by turning on a representative number of  fixtures that hot water fixtures at one  time and timing.

How long it takes to run  absolutely and what’s going to happen  with most tankless water heaters is that  when that flow rate that maximum flow  rate that’s available because of the  size of unit we have is exceeded the  flow will drop in all of those fixtures  so for example we have two showers going  which typically is the maximum flow  available from a tankless water heater  here in Colorado at the altitude where  we are as well as the cold incoming  water temperature that we have here in  Colorado or water because coming in at  40 degrees in the winter time and 50  degrees in the summer so that’s another  thing an inspector can measure what is  our incoming water temperature if he  wants to it’s real simple to get you  know a laser  thermometer yeah maybe that’s something  I’m sure that they carry with him they  should should measure the the incoming  water temperature typically we want to  see in Colorado an 80 degree rise or  other parts of the country where you  don’t size for an 80 degree rise  Southern Florida for example the water  is coming in at 75 degrees the water’s  coming in 75 degrees we don’t to get it  to 120 is only a 40 degree rise or 45  degree rise Dave what does an inspector  need to know in order to determine  whether or not the tankless water heater  is sized correctly for the home well  typically we do have some flow rates .

That oftentimes are posted on the side  of the unit again if we don’t have a  manual we can look at the flow rates for  the particular unit that’s there and  take a look at the different how many  fixtures there are in the house and how  each one would affect the flow coming  from this unit so for example the  typical hand sink is 1.2 to 1.6 gallons  per minute of flow the typical shower is  1.8 to 2.2 gallons per minute of flow  and what we’re talking about here is  flow from 40 degree incoming water to  120 degree that’s what we need to look  at for for colder climates for warmer  climates that’s different but you just  look at what temperature the incoming  water is typically a dishwasher is 0.9  to 1.1 gallons per minute where we run  into issues are bathtubs  Jacuzzi tubs and old-style washing  machines because all of these things do  dump a tremendous amount of water at  once if you’ve ever watched a jacuzzi  tub and with the Roman faucet on it  there’s six to seven gallons per minute  of water that that thing’s dumping  that’s way more than anyone tankless  water heater any one tankless water  heater can handle before that flow is  dropped.

So you know typically if an  inspector goes into a home that has a  jacuzzi tub and there’s only one unit  and he measures the flow at that jacuzzi  tub at six or seven gallons a minute  what you can do with a stopwatch in a  bucket very simple  gallons per minute then he needs to know  that that that this unit is not going to  be able to handle that plus anything  else in the house without a reduction in  flow right and again it’s about  education it’s about the the person  who’s buying that house understanding  what it is they’re getting and that  they’re gonna have to adjust their  lifestyle to a tankless water here and  when you say reduction in flow that  actually means reduction in flow not  that the water will get cooler like a  desk with a conventional water heater  that’s correct with a conventional water  heater runs out of hot water it’s done  and until it comes back it’s cold water  it’s no longer hot water  tankless water here the more modern the  newer units what will happen is that  flow will drop yes on the older units if  they’re running into some of the older  aqua stars some of the older Palomas  some of the older Takagi’s the thing  that they’re gonna see is that they  don’t adjust the flow  there’s no capacity of the unit to  actually adjust the flow of water  through what this flow Raider does it  actually adjusts the flow of water so it  comes out slower to keep that same  output temperatures that you have set on  the controller the older units are much  less sophisticated than that they don’t  have a computer they have no way to do  that so they’re gonna drop the  temperature and people are gonna get  cold showers and the old units.

Yeah Daveour inspector is likely to see electric  tankless water heaters and what about  point of useful are heaters there are  electric tankless water heaters  manufactured the problem that we see  with them is that they require  tremendous amount of electricity  obviously if anyone’s ever cooked on a  gas stove versus an electric stove the  difference in time that it takes to heat  water on a gas stove is considerably  less isn’t it  so typically heating water with gas  instantaneously like this a continuous  flow takes a lot less energy to do so  what we see with electric tankless water  heaters is they could consume up to 140  amps of power at 220 volts and most  homes don’t have that capability so we  don’t really see a lot of them out there  no and as far as a point of use units  the only point of use units that are  available in the United States  our electric units so we’re kind of back  to that same problem what we really see  for point of use are very low flow ones  that can make a cup of tea for example  you got 120 degree or 130 degree water  coming out but it’s a tiny amount of 120  degree water so you might usually see  those in a kitchen just serving the  kitchen sink and maybe the dish was  exactly.

I mean you go to Europe and Asia  and places across the puddle and you do  see gas point-of-use water heaters but  they are illegal here there’s no way to  put them in what about the cost  advantages in installing a tankless  water heater well a tank type water  heater of course is considerably less  than a tankless water heater but one of  the things that has come to the  forefront recently as the new naica  standard the national appliance an  energy conservation act has mandated for  tank type water heaters a new standard  and that actually has thinned the laws  of the heat transfer tube and at the  same time the jacket of the new tank  water heaters so when you go out to buy  a new tank water heater today the  typical life expectancy is three to five  years of a new tank type water heater  and that’s by government mandate and  that’s just because of thermal cycling  heating and cooling and stressing the  the over time well as we know the tank  type water heater it’s usually a glass  lined rolled steel tank and what happens  over time yes is that through  contraction and expansion that glass  eventually cracks  well now we’re relying on that metal to  keep that water in now if the metal is  one-third the thickness that it used to  be it’s gonna take a lot less time for  that tank type water heater to explode  and go all over the place so why did  they do that the government issued a  mandate as I said the naica standard.

It was was brought about by Reagan in 1978  if you see the yellow guides like this  mm-hmm Energy Guide see that on every  appliance that’s naked a tional  appliance energy conservation act that  was started back in 78 and applied to  furnaces and air conditioners  refrigerators every home appliance has  that  yellow energy guide on it well in 2004  they realized that they needed to do  something with water tanks because they  are the most inefficient appliance in  any home bar none less efficient than  even an old furnace so they reduced the  what the license so they reduced the  lifespan because their thinking was if  we can thin the wall of the heat  transfer tube that goes all the way up  through the middle of the tank we’re  gonna get more heat into that water  quicker aren’t we so that is correct but  what did they increase the efficiency by  any guesses one and a half percent one  and a half percent so the new water  tanks save all of 10 bucks a year over  the old water tanks.

richard

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