good afternoon YouTube it's been a little over two years since the tankless water heater was
installed and I've had a number of questions and comments on the various videos I made of
the installation tried to answer most of those in the comment section or in emails so I thought I'd
make this video to share some of those answers in a single video here about two years ago I made a
video where I described this selection process I went through to pick this particular model
and this is a Takagi tankless water heater so it runs on natural gas so the two main
features that I liked about this heater one is it could operate off of half inch gas line and
then the other feature I liked is that it could use PVC or plastic venting so just to summarize
the project a little bit right in here used to be a 40 gallon tank type water heater that was
installed when the house was built back in the mid 50's so the idea was get rid of the heater
that was here install a tankless heater over here and then in the space occupied by the tank heater
put in a utility sink anyway that was the rough plan and the goals were to reuse as much of the
infrastructure that exists right in this location for this heater and then also the utility sink so
to start off there were six items that this heater had to connect to one was the wall then I had to
connect to the gas for the fuel I had to connect to the water I needed to connect to the condensate
drain and I also needed some electricity to run the heater and then the sixth item was I needed
some way to vent the exhaust out of the house what I did was I prioritized those six things
in decreasing order of difficulty so difficulty meant how difficult was it going to be to adapt
the heater to the existing infrastructure I put the gas at the highest priority and then
I put mounting the heater to the wall second I put the venting third and then the water
connections then the condensate drain and then the last one was the electrical connections so
here's the gas pipe came out of the wall like I said this heater is rated to operate off of
half-inch gas pipe and it has a half-inch pipe nipple sticking out right there I chose to use
3/4 inch pipe to connect to it and that was based on one main reason so underneath the
house where this pipe comes up through the wall there's about 12 feet of half-inch gas
pipe already there under the house that would be rather difficult to change so that's why I
wanted a heater that would work on half-inch gas pipe and looking up in the gas flow tables
at 120,000 BTU perches what this heater runs 120 cubic feet per hour of gas I can have anywhere
from 10 to 15 feet of half-inch pipe I already had 12 feet and to come out of the wall and up to the
heater I needed another 3 feet of pipe so I could have run 1/2 inch pipe all the way up and that
probably would have worked the more conservative decision was to go with 3/4 inch rigid pipe so
it's a little more expensive maybe 1/3 more cost to buy a 3/4 inch pipe or fitting than a 1/2 inch
fitting so the idea was pay a little more upfront for the 3/4 inch pipe and fittings and have a
much better chance than trying to save a little money with half-inch pipe and then find out you
had problems and then have to replace it because that would be a major hassle to have to replace
all this pipe once everything was connected and that's also the reason I didn't use the corrugated
stainless steel tubing because that even though it's 3/4 or outside dimension the inside is
closer to half-inch rigid pipe so the decision was made to use 3/4 inch rigid pipe and that
gives you the biggest inside diameter and also the smoothest inside diameter and that will give
you the maximum flow and there's been no problem with flow even at maximum output no problem with
low gas pressure or anything however using rigid pipe means there's no adjustment in the gas it's
there so the idea was dropped the heater on top of the gas pipe and that's where the heater goes
so that's why I put locating or mounting the heater on the wall second and one problem that
brings up is that you can't ensure that the heater screws into walls it's because you can't move the
heater once the pipe is there to deal with that I put this plywood on the wall screwed the plywood
into the wall studs and then screwed the heater into the plywood and then I was able to get two
screws you can probably see there's a screw and a washer right there on the bottom there's also one
on the top that go into a wall studs then number three was the venting so one thing I did to make
the venting a little bit easier to line up there is when I put in the gas pipe I angled the pipe
so it came out to the left and up which moved the heater over and that made the venting easier to
line up so speaking of venting that was another hot question area one commenter said you can't
use PVC venting on a tankless heater because I installed a tankless heater in my house and it
has to use stainless steel venting and yes your heater probably needs stainless steel venting
there's two types of tankless heaters you've got the non-condensing heaters and then you've
got the condensing heaters the non-condensing or mid efficiency heaters have hot exhaust gas
that goes up well over the boiling point of water maybe 300 Fahrenheit 240 C so you've got very hot
gas going up the exhaust so in a non condensing heater you want to get the exhaust out of the
unit before the water vapor condenses out of the exhaust that's why they're called non condensing
and they require metallic venting because it's hot and they require stainless steel because if
the exhaust does condense inside of the pipe it will corrode things like galvanized so that's why
you need stainless pipe this is a condensing heater there's two heat exchangers inside
primary one is what heats the water up but the secondary heat exchanger extracts the heat out
of the exhaust the water condenses your the water vapor and that releases additional heat
to preheat the water before it goes into the burner heat exchanger so this heater is about
93 percent efficient compared to 83 percent for a non condensing heater so a couple other questions
I had on the venting I did have a little bit of trouble finding some of these fittings in
three inch PVC so one question was why didn't I use 2 inch PVC and the other question was why I
didn't use something like ABS which would be much easier to find in this size that's a very common
ABS pipe size and as I found out it's not quite as common in PVC so I had already had everything
except for a few fittings and then I found the difficulty in hindsight it probably would have
been much easier to do the venting in ABS which is a suitable material and the other reason was all
of the literature the webpage the brochures the installation manual all the videos you look at on
YouTube all the web page articles they all say PVC PVC PVC the heater comes with PVC adapters and at
that point all you think of is PVC I guess I never went back and reevaluated if I should use some of
the other materials in those other materials you can use PVC see PVC ABS or polypropylene
Oh abs would be a little bit easier to source PVC you know the heater came with
PVC fittings and one common or ass why didn't use two inch and two reasons one
is I already had all 3-inch stuff and then the existing ceiling penetration
and the roof penetration were for a 3-inch flew from the old heater
if I use two inch I'd have to plug up those holes for the water I decided to use flexible stainless
steel ho being there but the thinking was use the flexible because if I ever had to change this
heater out and maybe in ten years I can't get the exact same model and maybe the water hoses are in
a slightly different position I should be able to handle that and the gas I can just move it
in or out to shift the position of the gas pipe so that would be easy to deal with so water was
pretty straightforward just hook up two hoses and then as far as the condensate drain there's the
stand pipe for the clothes washer right there there's the output of the drain that was just
straight shot down the clear PVC tubing that I use seems to be adequate it flows condensate it
hasn't degraded it hasn't plugged up that works fine and then the electric I had a plug in the
wall right there for the closed washer just had to swap that out for a GFCI receptacle and right
now I'm actually running the tankless on my solar AC power inverter yeah that pretty much
covers all of the connection aspects some other questions I had were well why didn't I just run
the venting straight through the wall and right outside well if I did that my kitchen is on the
backside of this wall and the vent would come out in my kitchen cabinets if I were to come down here
there's a porch roof you can probably see out there so you can't have the vent under a porch
so yeah I could move the heater about 15 feet down the wall and make the venting really easy just out
the wall and that would be it but then I'd have to run gas water drainage electric 15 feet down
the wall because all of that stuff is right here that's why I put gas as number one I have to hook
up to the gas there's not a lot of wiggle room on the gas it was at about the maximum limit that
I could get away with on the gas pipe distance without having to run a new gas line under the
house so if you have a tank type heater like in a garage such as I have here if you can get rid
of that tank heater put a utility sink here so you can see here here's the utility sink here's
the drain here's the water it's a no-brainer to put the sink here the water heater here and as
you've seen in the to flush videos that I've done flushing the water heater is trivial you
just throw a bucket in the sink put your pump in it put your chemicals in it you hook the hoses up
here and turn on the pump you turn off the pump and you're done you know you don't even make a
mess so that's been a really killer combination is having the heater here the utility sink right next
to it all of this was possible because you got rid of the big 40 gallon tank that used to sit here
having this much mr. space you've got about 10 square feet of space that was recovered
and has gone to a very useful utility sink but yeah hopefully that answers all the
questions about installing the tankless why things were done in particular order so if
you have any other questions post up in the comment section down below and I'll put some
of the other installation videos over here on the left side and as always thanks for watching