Water Heaters: Tankless vs Traditional

[Maddog]

Hardly!!!

I would contract out but insurance won’t cover me since I’ve no clue what I’m doing.

and humble to boot . :;:cheers

 

[guywhofishes]

@guywhofishes

Do you contract out?
What is your hourly rate?

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You are the official water heating expert of NDA. ;:;bowdown ;:;bowdown ;:;bowdown

I bow in homage to you.



For us non-technical shmucks, do they have that check valve at say Home Depot?

menards

 

[Maddog]

Thanks Guy!

Did you mount it horizontally?

 

[guywhofishes]

Thanks Guy!

Did you mount it horizontally?

45 degrees / so the gate hangs open until pressure demand slaps it shut

 

[Maddog]

Thumbs Up

I know you wrote that earlier, but didn't know if that is what you meant.
Now with the picture it makes perfect sense.

Thanks

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What are your thoughts on "running" cost? - comparing the following:
1) old way of running the faucet for "90" seconds waiting for hot water

VS

2) your newly installed base, with the water heater having to do more heat cycles
(maybe that isn't true ?? as when you run for 90 seconds, you need more heat too. Guess the question is the perceived cost of additional heat loss by making it cycle more)

(perhaps, also cost of additional plumbing - how long will it take to recoup those costs?)

Just looking at costs -- not nicety of "instant" hot water. Understand I am a tight, old bastard, who pinches my pennies. : ) And I have patience for 90 seconds, do I like that, no.

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You had mentioned cold water being heavier than hot water. I get that but isn't that such a small factor in the relatively small volume you are talking about. Isn't it more about thermal transfer - meaning hot always flows to cold -- and with your water heater below (?) your faucets the heat will always rise more easily to that high point. Now you have introduced the potential for flow. So not only do you just have conduction but you also have flow convection?

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Did you consider an in-line heater close to your outlet? I didn't look into it. But don't they make something that only heats when there is flow?

 

[guywhofishes]

I had long wait times at a number of faucets - putting inline heaters in numerous locations seemed nuts.

I was “wasting” lots of water. That cost money too.

In winter none of the heat is wasted.

My water heater is electric but is on off peak so that’ll help.

In summer I might install a wifi flow control that I can set on schedule and/or temperature sensing.

There’s no way conduction alone gets it done. It wouldn’t have been an issue had conduction alone been capable of overcoming heat loss along the trunkline.

I’ll watch my bills and see if anything changes. I doubt it. Not sure I’ll care much. Ha ha. Washing hands with cold water sucked.

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The pex and fittings probably cost me $100 max. That’s child’s play compared to irritation of long waits.

 

[Maddog]

Thumbs Up

thanks for taking the time to share and responding

greatly appreciated

Dan

 

[Davey Crockett]

yep - I like cold tap water - dedicated return line all the way for me

luckily my entire house has one hot water leg - the kitchen is 2 light years away from the heater. Cheap bastard who built the house used 1/2 copper too. TAKES FOREVER FOR HOT WATER.

I'm upgrading to 3/4" for both lines, 1/2 for return cuz the pump is so slow

I'm tired of third world water in my $90,000 kitchen.

I used 3/4 and now I'm wondering if I'd be better off with 1/2 for my hot water supply lines ? Thinking FPS of flow to purge the cold water out of the system, the faucet is the limiting factor at least in my case. Our kitchen isn't that far away but still takes a long time.
I'm wondering if a water line heat tape would be a feasible solution ? Maybe insulate the pipe and put an on/off switch for it under the sink ?

 

[espringers]

the answer is fuck no you don't want half inch. especially if its pex where each fitting is actually 3/8. the loss of pressure wouldn't be worth whatever other benefit you think you might see. ask me how i know.

 

[Davey Crockett]

The kitchen sink faucet reduces down to 3/8 or even smaller in the faucet valve so in my mind the only way to get more volume is increase the pressure or install bigger faucet which isn't out of the question either I guess. Bigger pipe just takes longer to displace the cold water if the faucet GMP stays the same ?

 

[espringers]

pressure at the main meter being the same, if you have 3/4 inch all the way to the faucet that then reduces down to 3/8 inch at said faucet, you are going to be moving more volume at the faucet head than if you ran 1/2 all the way to the same faucet. that greater flow to the faucet head will result in greater pressure felt at the same faucet. if your goal is simply to be able to purge cold water from a pipe quicker, i am not sure if your thought process is right or not. a part of me says no. it should take the same amount of time. but, accomplished with less water maybe. we need a fluid mechanics guy. caveat: i am not one. so, i could be totally wrong about this! college was a long time ago.

 

[sl1000794]

We've had a hot water re-circ system since 1994 when we remodeled. The first pump went out and had to be replaced. The plumber that replaced it said that the industry had found that the original pumps that were used in these re-circ systems pumped the water too fast. Homes were experiencing pin hole leaks in the copper piping if there was any kind of burr at a soldered joint. The new pump that he installed only moved water about 5-7 feet per minute. That took care of the pin hole leak problem. Unfortunately for us our second pump went kaput over the weekend. Hope the plumber can get out here this week and replace it.

 

[Allen]

Ah, water. What a fun topic.

It's not so straight forward as to look at a single constriction point, as in the faucet being 3/8 inch which is necked down the 3/4 or 1/2 inch water line. Friction is real and there's greater friction per volume forces acting on water supply the smaller you go in line size, there are also differences in friction depending on material of said line. So if you are running a really long distance you can get unsatisfactory water supply/pressure when using 1/2 inch pipe as distances increase, but at the same time...if your faucet is one of the less-than-awesome 2 gpm wonders, it does take longer to empty a 3/4 inch line than it does a 1/2 inch water line.

The tipping point between time needed to exchange the volume in the 1/2 inch line vs the 3/4 inch line is probably nominal for most homes, but for very long runs (50+ ft) it may actually be several seconds. I have a pretty long run from my water heater to the master bath. If I need/want hot water quickly...I turn on both the shower and the sink. And ignore the $0.04 extra I just spent on water. Gotta choose your battles.

 

[guywhofishes]

I used 3/4 and now I'm wondering if I'd be better off with 1/2 for my hot water supply lines ? Thinking FPS of flow to purge the cold water out of the system, the faucet is the limiting factor at least in my case. Our kitchen isn't that far away but still takes a long time.
I'm wondering if a water line heat tape would be a feasible solution ? Maybe insulate the pipe and put an on/off switch for it under the sink ?

They make little 110V under-sink heaters - iff it’s just one sink driving you nuts. I had several “waiters” so I got aggressive.

Its so awesome not waiting- I practically giggle now. Small victories.

 

[Traxion]

We've had a hot water re-circ system since 1994 when we remodeled. The first pump went out and had to be replaced. The plumber that replaced it said that the industry had found that the original pumps that were used in these re-circ systems pumped the water too fast. Homes were experiencing pin hole leaks in the copper piping if there was any kind of burr at a soldered joint. The new pump that he installed only moved water about 5-7 feet per minute. That took care of the pin hole leak problem. Unfortunately for us our second pump went kaput over the weekend. Hope the plumber can get out here this week and replace it.

Done many a water damage repair job because of pinhole leaks and worse on old recirculation systems. Seems like one guy we damn near had his basement taken apart multiple times over three years. Elbows wore out, pin holes showed up, nasty deal.

 

[espringers]

Hijack... thoughts on life span of pex shark bite fittings? I can't help but worry bout such voodoo stuff that seems to good to be true.

 

[johnr]

Ah, water. What a fun topic.

I have a pretty long run from my water heater to the master bath. If I need/want hot water quickly...I turn on both the shower and the sink. And ignore the $0.04 extra I just spent on water. Gotta choose your battles.

Exactly the same, my kitchen faucet is on the back side of the master bathroom, both sinks take at least 40 seconds to draw the hot water. However once one or the other is warmed up they are both hot.
I run the shower and sink to speed this up in the mornings, however if just using the kitchen I turn the faucet on and then walk out to the mailbox to get the days bills, and when I get back in it is usually hot, sometimes I must walk quicker.

 

[guywhofishes]

Hijack... thoughts on life span of pex shark bite fittings? I can't help but worry bout such voodoo stuff that seems to good to be true.

Supposedly they’re good for the duration. I used them in some places but only those I can access readily…. the rotation capability was handy and a crimper wouldn’t fit into one place. Being able to uncouple and recouple is sure convenient.

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Done many a water damage repair job because of pinhole leaks and worse on old recirculation systems. Seems like one guy we damn near had his basement taken apart multiple times over three years. Elbows wore out, pin holes showed up, nasty deal.

gaaaaa!!!!

 

[guywhofishes]

So - here's the effect of my gravity loop. The green usage is "normal" electricity meter - and the orange is the off-peak meter that measures only my water heater (in the winter anyway).



Guess what day I turned the valve on for my gravity loop?

Turns out that 3/4" return line is maybe overkill - Ima close the valve part way and see if that doesn't calm things down. ;:;rofl

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January 2021 we used 7 KWH/day on water heater. = $21.12

January 2022 we used 14 KWH/day on water heater. = $33.40

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looks like my gravity circulator uses more hot water to heat the house than we use each day to shower, wash cloths, etc. ;:;rofl

In the winter... meh, I don't care (it's heat, so it’s not wasted). But in summer I'll be heating the house and then cooling it with AC. That'd be dumb.

So I'll either valve things down OR install a smart scheduled valve (shut it down most of the day and open it for typical shower and hot water usage hours).

 

[lunkerslayer]

Guywholikestoshare did you compensate for price increase of said kwh from year to year, you probably did that and I'm an idiot for stating the obvious.