--===============0240819912372635568==
boundary="----=_Part_3508317_1777824101.1643375585362"
------=_Part_3508317_1777824101.1643375585362
Content-Transfer-Encoding: quoted-printable
Jim, your plumber may have made that recommendation based on reliability a=
nd not necessarily on performance.=C2=A0=20
A coworker of mine installed a tankless heater because he has a wife and tw=
o daughters who would regularly empty the 30 gallon tank when showering.=C2=
=A0 He noted that the heater would delay heating water to the point that th=
e front-loading washer would never draw water long enough to get it to kick=
in.=C2=A0 My speculation is that the manufacturer programmed in a delay to=
confirm a good, solid hot water demand in pursuit of their energy rating.
15 feet of 1/2 inch tubing will hold about .05 gallons of water.=C2=A0 Most=
shower heads deliver 1 GPM.=C2=A0 That means it should take about 3 second=
s to purge the cold water out of the line.=C2=A0 OK, 6 seconds if you are d=
rawing a mix of hot and cold.=C2=A0 Several minutes is probably the heater =
control.=C2=A0 Maybe the flow switch is not sensitive enough to detect the =
flow at that level.
=20
Dave=20
=20
=20
-----Original Message-----
From: Jim Stone <1789alpine@gmail.com>
To: Shop Talk <shop-talk@autox.team.net>
Sent: Thu, Jan 27, 2022 8:30 pm
Subject: [Shop-talk] Whole house tankless heater experience. Was: tankless/=
instant water heater
I held off answering Jimmie=E2=80=99s question below until the original top=
ic seemed to have played out. =C2=A0With that now apparently done, here is =
my experience with full house tankless heaters.
I have two tankless heaters, one in my garage - which has a small living ar=
ea adjacent to it and two bedrooms and a bathroom above it - and one in my =
house. =C2=A0Both are propane fired, as I live in a fairly rural area and n=
atural gas isn=E2=80=99t available here. The garage unit is a combination D=
HW and hydronic heating unit (I have heated floors in the shop and downstai=
rs living area) made by a company called Laars. =C2=A0https://www.laars.com=
. I have no complaints with that unit and love having heated floors in the =
garage. =C2=A0(I ran the lines before the concrete was poured.)
My house is a very small (780 sq ft) ranch house and has a Rheem tankless u=
nit (RTGH-900VLP-2) that was installed when the house was completely rebuil=
t=C2=A0(as in, new house built on the original foundation)=C2=A0three years=
ago. The shower is no more than 15ft from the heater, yet it takes several=
minutes to get hot water to the shower. =C2=A0It was instantaneous when we=
had a conventional tank unit, but my community requires new construction t=
o meet specific energy efficiency standards that required us to use a tankl=
ess unit. =C2=A0I complained about the heat when the unit was new and an in=
spection revealed a faulty mixing valve, which was replaced under warranty.=
=C2=A0I was still unhappy and Rheem told me how to bypass the preset maxim=
um temperature of 120=C2=BA and it is better with the unit set to 130=C2=BA=
or 140=C2=BA, but I have a hard time believing that should be necessary. =
=C2=A0As I said, it took a separate small electric unit to be able to get f=
ast heat to the kitchen and there is maybe 40=E2=80=99 of insulated PEX pip=
e between the heater and the sink. (The temp in the basement is generally a=
round 60=C2=BA.)
The Rheem unit was recommended by my plumber and is highly rated, so maybe =
my unit is just a lemon. =C2=A0But, I spoke with a plumber before installin=
g the 7.5 gallon unit for the sink and he told me he installs a lot of smal=
l =E2=80=98point of use=E2=80=99 tanked units in house with tankless heater=
s, so my complaint can=E2=80=99t be unique to my heater. =C2=A0Overall, I l=
ike the fact that my house is very energy efficient, but I really miss the =
days when I could hop in the shower immediately and not have to worry about=
waiting for the water to warm up.=C2=A0
Jim
------=_Part_3508317_1777824101.1643375585362
Content-Transfer-Encoding: quoted-printable
<div style=3D"color:black;font: 12pt Arial, Helvetica, sans-serif;">
<div> <font size=3D"3">Jim, your plumber may have made that recommendation =
based on reliability and not necessarily on performance. <br>
</font></div>
<div><br>
</div>
<div><font size=3D"3">A coworker of mine installed a tankless heater becaus=
e he has a wife and two daughters who would regularly empty the 30 gallon t=
ank when showering. He noted that the heater would delay heating wate=
r to the point that the front-loading washer would never draw water long en=
ough to get it to kick in. My speculation is that the manufacturer pr=
ogrammed in a delay to confirm a good, solid hot water demand in pursuit of=
their energy rating.</font></div>
<div><br>
</div>
<div><font size=3D"3">15 feet of 1/2 inch tubing will hold about .05 gallon=
s of water. Most shower heads deliver 1 GPM. That means it shou=
ld take about 3 seconds to purge the cold water out of the line. OK, =
6 seconds if you are drawing a mix of hot and cold. Several minutes i=
s probably the heater control. Maybe the flow switch is not sensitive=
enough to detect the flow at that level.</font><br>
</div>
<div> <br>
</div>
<div style=3D"clear:both"><font size=3D"4">Dave </font><br>
<br>
</div>
<div> <br>
</div>
<div> <br>
</div>
<div style=3D"font-family:arial,helvetica;font-size:10pt;color:black"><font=
size=3D"2">-----Original Message-----<br>
From: Jim Stone <1789alpine@gmail.com><br>
To: Shop Talk <shop-talk@autox.team.net><br>
Sent: Thu, Jan 27, 2022 8:30 pm<br>
Subject: [Shop-talk] Whole house tankless heater experience. Was: tankless/=
instant water heater<br>
<br>
<div id=3D"yiv3038752637">
<div>I held off answering Jimmie=E2=80=99s question below until the origina=
l topic seemed to have played out. With that now apparently done, her=
e is my experience with full house tankless heaters.<br class=3D"yiv3038752=
637" clear=3D"none"><br class=3D"yiv3038752637" clear=3D"none">I have two t=
ankless heaters, one in my garage - which has a small living area adjacent =
to it and two bedrooms and a bathroom above it - and one in my house.  =
;Both are propane fired, as I live in a fairly rural area and natural gas i=
sn=E2=80=99t available here. The garage unit is a combination DHW and hydro=
nic heating unit (I have heated floors in the shop and downstairs living ar=
ea) made by a company called Laars. <a rel=3D"nofollow noopener noref=
errer" shape=3D"rect" target=3D"_blank" href=3D"https://www.laars.com/"; cla=
ss=3D"yiv3038752637">https://www.laars.com</a>. I have no complaints with t=
hat unit and love having heated floors in the garage. (I ran the line=
s before the concrete was poured.)<br class=3D"yiv3038752637" clear=3D"none=
"><br class=3D"yiv3038752637" clear=3D"none">My house is a very small (780 =
sq ft) ranch house and has a Rheem tankless unit (RTGH-900VLP-2) that was i=
nstalled when the house was completely rebuilt (as in, new house built=
on the original foundation) three years ago. The shower is no more th=
an 15ft from the heater, yet it takes several minutes to get hot water to t=
he shower. It was instantaneous when we had a conventional tank unit,=
but my community requires new construction to meet specific energy efficie=
ncy standards that required us to use a tankless unit. I complained a=
bout the heat when the unit was new and an inspection revealed a faulty mix=
ing valve, which was replaced under warranty. I was still unhappy and=
Rheem told me how to bypass the preset maximum temperature of 120=C2=BA an=
d it is better with the unit set to 130=C2=BA or 140=C2=BA, but I have a ha=
rd time believing that should be necessary. As I said, it took a sepa=
rate small electric unit to be able to get fast heat to the kitchen and the=
re is maybe 40=E2=80=99 of insulated PEX pipe between the heater and the si=
nk. (The temp in the basement is generally around 60=C2=BA.)<br class=3D"yi=
v3038752637" clear=3D"none"><br class=3D"yiv3038752637" clear=3D"none">The =
Rheem unit was recommended by my plumber and is highly rated, so maybe my u=
nit is just a lemon. But, I spoke with a plumber before installing th=
e 7.5 gallon unit for the sink and he told me he installs a lot of small =
=E2=80=98point of use=E2=80=99 tanked units in house with tankless heaters,=
so my complaint can=E2=80=99t be unique to my heater. Overall, I lik=
e the fact that my house is very energy efficient, but I really miss the da=
ys when I could hop in the shower immediately and not have to worry about w=
aiting for the water to warm up. <br class=3D"yiv3038752637" clear=3D"=
none"><br class=3D"yiv3038752637" clear=3D"none">Jim</div>
</div>
</font></div>
</div>
------=_Part_3508317_1777824101.1643375585362--
--===============0240819912372635568==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
Shop-talk@autox.team.net
Archive: http://www.team.net/pipermail/shop-talk http://autox.team.net/archive
--===============0240819912372635568==--
|