Tankless hot water heater... school me.

[Instigator]

Here is the difference between the 2 common system's.
Just don't use anyone's manifold.
Have the plumber custom build the manifolds out of copper tubing and brass ball valves.
Then parts are available at any hardware store.

Trunk & Branch and Home-Run Piping

Trunk & branch and home-run piping systems are the two most popular ways to configure PEX tubing for domestic water. The traditional trunk & branch method includes main hot and cold lines t…

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[CobraDave]

It seems like a tankless would be the way to go in a havasu vacation house. Because a water heater isn’t constantly running. I’m hopefully going to start building. I don’t care about wasting a little water. What should I do?


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[Flying_Lavey]

Recirc pump, and most importantly..... insulation on the lines. Most aren't insulated and with long attic runs you have a LOT of heat transfer (loss in the winter on the hot side and gain in the summer on the cold side). Insulate the lines, plumb in a return loop (insulate that as well) and install a recirc pump. Instant (almoat) and endless hot water is the best.

Or you could put a little electric insta-hot under the sink that would heat up the water as soon as you need it but when the hot water gets there from the heater it's not used anymore (reaches its set-point and shuts off its heating element).

DB, and others......
Cost aside. Speaking in Physics here.
If piped correctly, you do not need, and frankly, do not want a recirc pump. 1 more mechanical device maintain.
You do need a 3rd pipe. Usually 1/2" copper. At your bathroom end tied into the highest point (very important) on the HW side before the bathroom.
At the water heater end tie into the lowest. On Water heater tanks. We would unscrew the drain spigot off the bottom, put a nipple and a tee (standard 3/4" NPT) in and then the drain spigot back in. tie in the return line to the Tee.
Point being, HW rises. Pushing thru the pipe thru convection, pushing cooler water back down the return to the bottom of the tank. Heat migrates up. No pump necessary if it set up correctly. Same principle that keep hot air ballon aloft.
Ask any old plumber. Should work on tankless but Idk for sure.
FYI, Pipefitter, 42 yrs. Retired.

Won't work on a tankless. They have to flow a certain amount to fire up. Convection alone wouldn't do it.

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[TPC]

Our tank water heater doubles as water storage during earthquakes.

 

[WYRD]

Toss a five gallon bucket in the shower and see how long it takes to fill up.

It may not be as much as you think. The new low flow shower heads only flow 2 or 2.5 gallons a minute. It may seem like an eternity when you are
standing there naked waiting to get in, but it may not actually be that much water.

Oh, then use the water in the bucket for watering your house plants. I suggest you do that naked too.

This......I had the same issue. Found out the amount of water was about three gallons. That's equal to a couple of toilet flushes. I took the low flow restrictor off the closest sink and turn that on along with the shower in the morning while the water gets hot. Takes less than 30 seconds now. Give it a try... One bit of advice though...

Don't take a shower while drunk with this method you might end up forgetting to turn the sink off before you get in the shower, have amazing shower sex with your SO, and pass out after getting out while leaving the hot water run at the sink all night long

 

[GetNautical]

We recently installed Rinnai Tankless and it works great. Has a built in recirculation pump to push the hot water through the house. Connects to your wifi so you can adjust the temp and set the pump schedule, turn of/off the pump etc. from an app on your phone. Really easy to use and plenty of hot water. Wouldn't get one without the recirculation pump.

 

[Fastdadtsmith]

A couple of points to consider,
1. Tankless have a flow rating related to temperature rise and power or gas supply needed. You can't just add a 120 volt water heater under your sink and raise the temp 50 degrees in a short time. If you remove some of the restrictions you may not get the needed temperature rise as water goes thru heater too fast.
2. A tank type needs a pop off valve routed outside.

As stated before in all scenarios, you're either wasting water or energy. With a tankless you gain space. With a circ pump you gain time.

 

[SoCalDave]

Here's a best seller (Bosh) on Amazon for $157. Mini tank 2.5gl / 120vac. Easy to install and can plug directly into an outlet under your sink.
This is really a no brainer for the kitchen sink.

As for the shower just take the head off from the wall/ceiling stub and see if there is a restrictor disc in it. If so just remove it or drill the hole a little bigger.

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 2.5-Gallon (ES2.5) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted - - Amazon.com

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 2.5-Gallon (ES2.5) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted - - Amazon.com

www.amazon.com

 

[Mandelon]

I'm curious how much water is really going to end up in the bucket. Take off the shower heads and dig out the little doohickey that slows down the water flow. Sometimes you have to actually drill it out. But the water flow is soooo much better!

If you have teen kids you almost need a tankless. If the kids beat you into the shower, they use up all the hot water.

I have had a Rinnai for 15 years or more. I flush it every couple years. It works great with zero problems.

 

[steamin rice]

This may be more than you want to deal with, but if your biggest concern is the long wait to have hot water in the master bath, then could you add a secondary smaller water heater in the master closet or even outside the house near the master bath? Your pex for the plumbing may be running in the attic, so it might not be too bad to tap into the plumbing near the master bath and add another heater. Again, this might be more than you are looking to do on a brand new house, but it could be an option to consider if it's still bothering you after a few months.

 

[DaytonaBabe]

This may be more than you want to deal with, but if your biggest concern is the long wait to have hot water in the master bath, then could you add a secondary smaller water heater in the master closet or even outside the house near the master bath? Your pex for the plumbing may be running in the attic, so it might not be too bad to tap into the plumbing near the master bath and add another heater. Again, this might be more than you are looking to do on a brand new house, but it could be an option to consider if it's still bothering you after a few months.

Thanks for the input. Definitely not wanting to make any modifications on the new house at this point (we've only been in for 2 months). If the removal of the flow restrictors doesn't improve the situation and it continues to be an issue down the line, it's good to know that this is an option. From what everyone has said, it seems like this is really the only way to expedite hot water directly to the master.

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[DaytonaBabe]

Our tank water heater doubles as water storage during earthquakes.

I like not having the big tank in the way. We begin the dig on the pool in a month, so we'll just use that as our emergency water source [emoji106]

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[DaveC]

Unrelated question (sorry DB)

Anyone use or know anything about electric tankless water heaters?

 

[DaveC]

Baller....

did you buy this place or build it?

I remember some discussion of buying a lot and building? What happened?

There's nothing wrong with the tankless itself, the hot water just has a long way to travel. View attachment 971360

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[Waterjunky]

I have a similar issue at my house. The water heater is at the exact opposite end as the shower. When I redo some plumbing (currently 70 year old galvanized ) I will be adding another water heater at that end of the house with an isolation valve between them. If one dies, open the valve and you are functional until repairs can be made.

 

[DaytonaBabe]

Baller....

did you buy this place or build it?

I remember some discussion of buying a lot and building? What happened?

We had it built [emoji4] The process started a year ago and we've been in for 2 months now. Loving it!

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[Andy B.]

Glad you started this thread was thinking about getting one not anymore.

 

[Activated]

Unrelated question (sorry DB)

Anyone use or know anything about electric tankless water heaters?

We just replaced our water heater. I asked the plumber about tankless, he said we wouldn’t be happy with it as our entire house is electric. He recommends tankless for most of his customers unless they are electric.

 

[BUSTI]

Our tank water heater doubles as water storage during earthquakes.

Not to mention if there is another revolution.

 

[NicPaus]

Unrelated question (sorry DB)

Anyone use or know anything about electric tankless water heaters?

It gets asked on the regular on the plumbing forum. Nothing good they recommend.

I would never install a tankless on my house unless I needed the space where tank is. But like I just did at my Parker pad. Added a water heater house outside and made the water heater closet a clothes closet. There are a lot of nice units but when they need work can get expensive.

 

[rivermobster]

We recently installed Rinnai Tankless and it works great. Has a built in recirculation pump to push the hot water through the house. Connects to your wifi so you can adjust the temp and set the pump schedule, turn of/off the pump etc. from an app on your phone. Really easy to use and plenty of hot water. Wouldn't get one without the recirculation pump.

That's very cool.