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Re: [Shop-talk] Whole house tankless heater experience. Was: tankless/in

To: DAVID MASSEY <dave1massey@cs.com>
Subject: Re: [Shop-talk] Whole house tankless heater experience. Was: tankless/instant water heater
From: Jim Stone <1789alpine@gmail.com>
Date: Fri, 28 Jan 2022 19:30:50 -0500
Cc: Shop Talk <shop-talk@autox.team.net>
Delivered-to: mharc@autox.team.net
Delivered-to: shop-talk@autox.team.net
References: <1UbickM8cG.1ScZN3OsJa4.ref@johns-desktop> <1UbickM8cG.1ScZN3OsJa4@johns-desktop> <16F494C6-A6A2-4743-9A1C-8996238C89B2@gmail.com> <2a3ddeec-3023-c6eb-a802-785e5c62f899@sackheads.org> <23662393-247F-4B20-8E85-93B21B18231B@gmail.com> <1224379374.3508318.1643375585364@mail.yahoo.com>
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Thanks, Dave.  That is an interesting way to put it.  I think I will =
time the heat and try contacting Rheem.  You never know.

> On Jan 28, 2022, at 8:13 AM, DAVID MASSEY <dave1massey@cs.com> wrote:
>=20
> Jim, your plumber may have made that recommendation based on =
reliability and not necessarily on performance. =20
>=20
> A coworker of mine installed a tankless heater because he has a wife =
and two daughters who would regularly empty the 30 gallon tank when =
showering.  He noted that the heater would delay heating water to the =
point that the front-loading washer would never draw water long enough =
to get it to kick in.  My speculation is that the manufacturer =
programmed in a delay to confirm a good, solid hot water demand in =
pursuit of their energy rating.
>=20
> 15 feet of 1/2 inch tubing will hold about .05 gallons of water.  Most =
shower heads deliver 1 GPM.  That means it should 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 is probably the heater =
control.  Maybe the flow switch is not sensitive enough to detect the =
flow at that level.
>=20
> Dave=20
>=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
>=20
> I held off answering Jimmie=E2=80=99s question below until the =
original topic seemed to have played out.  With that now apparently =
done, here is my experience with full house tankless heaters.
>=20
> I have two tankless 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 isn=E2=80=99t available here. The garage unit =
is a combination DHW and hydronic heating unit (I have heated floors in =
the shop and downstairs living area) made by a company called Laars.  =
https://www.laars.com <https://www.laars.com/>. I have no complaints =
with that unit and love having heated floors in the garage.  (I ran the =
lines before the concrete was poured.)
>=20
> My house is a very small (780 sq ft) ranch house and has a Rheem =
tankless unit (RTGH-900VLP-2) that was installed when the house was =
completely rebuilt (as in, new house built on the original foundation) =
three years ago. The shower is no more than 15ft from the heater, yet it =
takes several minutes to get hot water to the shower.  It was =
instantaneous when we had a conventional tank unit, but my community =
requires new construction to meet specific energy efficiency standards =
that required us to use a tankless unit.  I complained about the heat =
when the unit was new and an inspection revealed a faulty mixing 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 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.  As I said, it took a separate =
small electric unit to be able to get fast heat to the kitchen and there =
is maybe 40=E2=80=99 of insulated PEX pipe between the heater and the =
sink. (The temp in the basement is generally around 60=C2=BA.)
>=20
> The Rheem unit was recommended by my plumber and is highly rated, so =
maybe my unit is just a lemon.  But, I spoke with a plumber before =
installing the 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 like 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.=20
>=20
> Jim


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<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; =
charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; line-break: after-white-space;" =
class=3D"">Thanks, Dave. &nbsp;That is an interesting way to put it. =
&nbsp;I think I will time the heat and try contacting Rheem. &nbsp;You =
never know.<br class=3D""><div><br class=3D""><blockquote type=3D"cite" =
class=3D""><div class=3D"">On Jan 28, 2022, at 8:13 AM, DAVID MASSEY =
&lt;<a href=3D"mailto:dave1massey@cs.com"; =
class=3D"">dave1massey@cs.com</a>&gt; wrote:</div><br =
class=3D"Apple-interchange-newline"><div class=3D"">
<div style=3D"font-style: normal; font-variant-caps: normal; =
font-weight: normal; font-stretch: normal; font-size: 12pt; line-height: =
normal; font-family: Arial, Helvetica, sans-serif;" class=3D"">
<div class=3D""> <font size=3D"3" class=3D"">Jim, your plumber may have =
made that recommendation based on reliability and not necessarily on =
performance.&nbsp; <br class=3D"">
</font></div>

<div class=3D""><br class=3D"">
</div>

<div class=3D""><font size=3D"3" class=3D"">A coworker of mine installed =
a tankless heater because he has a wife and two daughters who would =
regularly empty the 30 gallon tank when showering.&nbsp; He noted that =
the heater would delay heating water to the point that the front-loading =
washer would never draw water long enough to get it to kick in.&nbsp; My =
speculation is that the manufacturer programmed in a delay to confirm a =
good, solid hot water demand in pursuit of their energy =
rating.</font></div>

<div class=3D""><br class=3D"">
</div>

<div class=3D""><font size=3D"3" class=3D"">15 feet of 1/2 inch tubing =
will hold about .05 gallons of water.&nbsp; Most shower heads deliver 1 =
GPM.&nbsp; That means it should take about 3 seconds to purge the cold =
water out of the line.&nbsp; OK, 6 seconds if you are drawing a mix of =
hot and cold.&nbsp; Several minutes is probably the heater =
control.&nbsp; Maybe the flow switch is not sensitive enough to detect =
the flow at that level.</font><br class=3D"">
</div>

<div class=3D""> <br class=3D"">
</div>

<div style=3D"clear:both" class=3D""><font size=3D"4" class=3D"">Dave =
</font><br class=3D"">
<br class=3D"">
</div>

<div class=3D""> <br class=3D"">
</div>

<div class=3D""> <br class=3D"">
</div>

<div style=3D"font-family: arial, helvetica; font-size: 10pt;" =
class=3D""><font size=3D"2" class=3D"">-----Original Message-----<br =
class=3D"">
From: Jim Stone &lt;<a href=3D"mailto:1789alpine@gmail.com"; =
class=3D"">1789alpine@gmail.com</a>&gt;<br class=3D"">
To: Shop Talk &lt;<a href=3D"mailto:shop-talk@autox.team.net"; =
class=3D"">shop-talk@autox.team.net</a>&gt;<br class=3D"">
Sent: Thu, Jan 27, 2022 8:30 pm<br class=3D"">
Subject: [Shop-talk] Whole house tankless heater experience. Was: =
tankless/instant water heater<br class=3D"">
<br class=3D"">

<div id=3D"yiv3038752637" class=3D"">
<div class=3D"">I held off answering Jimmie=E2=80=99s question below =
until the original topic seemed to have played out. &nbsp;With that now =
apparently done, here is my experience with full house tankless =
heaters.<br class=3D"yiv3038752637" clear=3D"none"><br =
class=3D"yiv3038752637" clear=3D"none">I have two tankless 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. &nbsp;Both are =
propane fired, as I live in a fairly rural area and natural gas isn=E2=80=99=
t available here. The garage unit is a combination DHW and hydronic =
heating unit (I have heated floors in the shop and downstairs living =
area) made by a company called Laars. &nbsp;<a rel=3D"nofollow noopener =
noreferrer" shape=3D"rect" target=3D"_blank" =
href=3D"https://www.laars.com/"; =
class=3D"yiv3038752637">https://www.laars.com</a>. I have no complaints =
with that unit and love having heated floors in the garage. &nbsp;(I ran =
the lines 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 installed when the house was completely =
rebuilt&nbsp;(as in, new house built on the original =
foundation)&nbsp;three years ago. The shower is no more than 15ft from =
the heater, yet it takes several minutes to get hot water to the shower. =
&nbsp;It was instantaneous when we had a conventional tank unit, but my =
community requires new construction to meet specific energy efficiency =
standards that required us to use a tankless unit. &nbsp;I complained =
about the heat when the unit was new and an inspection revealed a faulty =
mixing valve, which was replaced under warranty. &nbsp;I was still =
unhappy and Rheem told me how to bypass the preset maximum 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. &nbsp;As I =
said, it took a separate small electric unit to be able to get fast heat =
to the kitchen and there is maybe 40=E2=80=99 of insulated PEX pipe =
between the heater and the sink. (The temp in the basement is generally =
around 60=C2=BA.)<br class=3D"yiv3038752637" 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 unit is just a lemon. =
&nbsp;But, I spoke with a plumber before installing the 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. &nbsp;Overall, I like =
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.&nbsp;<br class=3D"yiv3038752637" =
clear=3D"none"><br class=3D"yiv3038752637" clear=3D"none">Jim</div>
</div>
</font></div>
</div>
</div></blockquote></div><br class=3D""></body></html>=

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