Extra H20 heater

[unheatedgarage]

Hi, a little thread necromancy here.

My old 40 gal gas water heater died this summer. Instead of replacing it, I went with point-of-use electric heaters (120v; 16 amps) under the kitchen and bathroom sinks. The bathroom heater also got branched off to supply hot water for the tub. At less than a third of a gallon a minute, it makes for super minimal showers, but it does the trick.

I measured up to 120 degree water coming out of the faucet in August (which was too hot then), but as the weather’s been cooling down I fear the heaters might not be able to warm up the cold ground water enough to make for a comfortable shower. However, since this is a one-person household, I’m not concerned about anyone else being unhappy with the set up. Mostly I’m looking forward to seeing how much my water and gas usage drops compared to last winter.

As far as the work of re plumbing went, that was the easy part--just capped off the hot water lines and plumbed the heaters directly off the cold water. The hard part was going back-and-forth to the hardware store trying to figure out what fittings I needed.

All in all, I’m pleased with the results. I, too, am curious what bikin’ Ed ended up doing...

[Daox]

Welcome to the site unheatedgarage!

Unless your well is very shallow, your ground water should be a fairly constant temperature year round.

[Minimac]

Why not just run a return from the end of the hot line( where it goes up to the bathrooms) back into the hw tank. Natural convection will greatly reduce the waiting time. it works best if you can install a tee at the tank drain and pipe the return into that.

[stevehull]

I agree with Randen on this - use a circulation pump. Your idea of using the point of use electric water heater is good, but the cost of the unit (at least $100 for the smallest 2 kW units) and the cost of using electricity will never be offset by using a natural gas water heater.

Using electricity to heat water, when natural gas is already at the house will never be an economical solution (unless you are Xringer and have extra solar PV kW to spare).

Alternatively, might I suggest using a tankless natural gas water heater? That way, you have the best of all worlds - no standing tank loss, use of inexpensive natural gas and a water heater that will last FAR longer than a tank type unit.

Steve

[WyrTwister]

My situation is thus ;

The gas WH is pretty close to the main bath . Quite a way to the kitchen and even further to the back bath .

House is pier & beam construction .

None of the water lines are insulated .

I am to old and fat to get under the back bath . I am almost too old and fat to get under the kitchen . With some difficulty I can get under pretty much the rest of the house .

The gas WH is starting to grumble , burp and belch . :-( Approaching the end of its useful life .

Due to the current plumbing code requirements of 2 air ducts , I will most likely go back with an electric WH . I realize the energy costs will be higher , but I am just going to live with that .

One of the first things I am going to try is to insulate the HW lines I can get to .

Due to the long wait for HW , the water to the dish washer cools down in between fill / wash cycles . I thought about a small under counter electric WH . But when I priced them , they are close to the same price as 30 - 40 gallon " conventional " WH's . :-(

Do not think I am going to do that .

I am thinking about installing a 40 gal electric WH in the laundry room . We do not use HW for washing clothes , but there is space there and it would get the WH closer to the kitchen and the main bath . A little further from the back bath .

The back bedroom & bath are for guest use only . So , that is a lower priority .

I have never had an electric WH . But here is my take on them . They use energy when they are heating water . It seems that all the 30 - 40 gal WH's have one or two 4500 Watt elements . When two , they are wired for non simotanious operation & need to be feed with a 30 amp 240 VAC circuit .

After an electric WH gets the water up to temp , the only energy they use is to replace heat lost through the outside of the tank .

The better insulated , the less heat loss . Plus , a timer can be installed for off hour energy reduction / consumption . May put a fiberglass " blanket " around it ?

I do not know about Pex pipe ? There have been several generations of plastic pipe through the years ( Quest was one ) . Seems like flaws were found with them and they were withdrawn from the market ?

So , I will probably swallow the cost and use copper .

I might install another electric WH in the back bath , at some point in the future ?

God bless
Wyr

PS The only difference I see in energy consumption between a 30 & a 40 gal heater is the increased surface area ( to loose heat ) of the 40 ?

[Daox]

PEX is cheaper and widely accepted for DHW use. It has been in use for well over a decade and has proven itself not to just be a 'new thing'.

How much are you finding 40 gal water heaters for? The cheapest ones I've found are $225 on homedepot.com, and most are $300-$400. The on demand (point of use) electric water heaters start just over $150.

[WyrTwister]

Originally Posted by Daox

PEX is cheaper and widely accepted for DHW use. It has been in use for well over a decade and has proven itself not to just be a 'new thing'.

How much are you finding 40 gal water heaters for? The cheapest ones I've found are $225 on homedepot.com, and most are $300-$400. The on demand (point of use) electric water heaters start just over $150.

Home Depot had the 40 gal electric WH on sale for $ 199 , before Christmas . Do not know if it is still on sale ?

Lowes was about $ 225 .

God bless
Wyr

[jeff5may]

Wyr,

Please don't be conned into buying a 3 or 6 year "trailer" water heater. Yes, they are inexpensive. No, they're not worth it. You would be better off buying a point-of use unit for the same price. Just ask yourself: "How soon do I want to have problems?" With a $199 electric water heater, it may break being installed. If you get lucky, it might even last a decade.

If you have a natural gas water heater already, try your best to replace it with another gas unit. The newer "not cheap" units are much more efficient than their predecessors, and natural gas is cheaper by the BTU anyway. Having a new unit installed to code might cost extra, but the long-term savings will pay this expense off along with the unit.

On the other side, not all point-of use water heaters are built the same.

The tankless "under-counter" units are the most efficient, but generally will only supply one faucet. They are meant to be run using the cold water supply for a source. They depend on a flow-meter (not a thermostat) to energize the heating element. They generally will not provide much more than 1 GPM of hot water, and exit water temp is very much a function of flow rate. Sized correctly, they will provide an endless output of hot water. Most importantly, they will not scald you with super-hot water, due to the flow-meter having a low-flow threshold that will not allow the unit to produce scalding water, ever.

The point-of-use units with tanks in them are basically little brothers of the full-size units. They have thermostats and tank losses. They can be plumbed into the existing hot water lines. They will not provide endless hot water, but the water coming from the main DHWH can replenish the hot water supply before the point-of use unit runs out of hot water during periods of high demand.

Both types of point-of-use units being sold at Slows and Home Despot are priced in the "affordably disposable" range, so expect them to last a decade or less. If you are looking for something that will last longer, it's gonna cost more than $200. The factory authorized plumbing supply warehouse in town might have 1 in stock to look at, but will be able to get the one you want in 3 days.

[WyrTwister]

We have so much " lime " in our water , I am told the tank-less WH's stop up pretty quickly ?

Current plumbing codes require a fresh air vent high and low , in a WH closet . I can not do that . Not enough space . Thus , I plan to install an electric WH .

The gas WH will probably be abandoned in place , short term .

The plan is to put the new electric 40 gal WH in the laundry room , next to the washing machine .

GE 40 gal. Medium 6 Year 4500-Watt Double Element 240-Volt Electric Water Heater-GE40M06AAG at The Home Depot

God bless
Wyr

[AC_Hacker]

Originally Posted by WyrTwister

...The plan is to put the new electric 40 gal WH in the laundry room , next to the washing machine...

There are various rationales for locating a DWH.

Some people put them at the center of the house so that all taps are about equal distance away.

Some put the DWH as near as possible to the outlet through which the greatest volume of heated water flows (sometimes laundry, sometimes bathroom).

In my opinion, the very best location for a water heater is as close as possible to the most frequently used outlet... which in most cases is the kitchen sink.

The reason is that there is a "slug" of water that has become cold inside the pipe, and that water is allowed to run (wasting water & time) until the hot water begins to flow. By locating the DWH near the most frequently used tap, the slug quantity and time are remarkably reduced. With the advent of popular electric demand heaters, the water heater can easily be put under the kitchen sink, inside the cabinet. This way the distance from the DWH to the tap can be measured in inches rather than feet.

Also, if you live in a climate that requires 'mostly heating', then if it is possible to locate the DWH in the heated section of the house, it's wasted heat is put to good use. Of course, if your climate is 'mostly cooling' then the DWH should be located outside the heated envelope.

* * *

On a not unrelated note, two of my personal friends are going to considerable effort (separate installs) to locate their furnaces outside the heated envelope, in barely-heated attics, which make me wonder if there is any hope for humanity... at all?

You can lead a horse to water, but wise energy decisions have a long way to go.

-AC