Installing a new electric water heater.

eserps89

Ok. I have an oil furnace, heating the baseboards and fixtures. 

I’ve already purchased an 80 gal electric water heater

My plan is

bring the cold into the water heater, ok that’s easy, I even put an expansion tank. 

But onto the hot. 

My plan is to just cut the hot out of the furnace and cap the furnace off so my furnace will be dedicated to just the baseboards. 

Then I just re-routed all my hot fixtures directly to the water heater. 

Ive only replaced water heaters, I’ve never done a new install with a furnace being involved like this. 

Am I just over thinking? Is this ok??

capping the hot at the furnace and bringing all showers and sinks directly to the hot on the water heater. Again, removing all fixtures from the furnace and dedicating fixtures to only the electric water heater??


I have everything ready to go, tomorrow all I have to do is switch from furnace to water heater and connect the cold to the main line. 

Ironman

Don’t cap both sides of the hot water coil in the boiler! It must be left open to the atmosphere.

Youll also want to turn down the low limit on the boiler’s triple aquastat so it doesn’t remain hot all the time.

eserps89

Sorry, both sides? 

I am just going to cut the 1 pipe at the first fixture add a ball valve just for safe measures  and a cap on the other side of the ball valve for the furnace.  

The re route from my first fixture (which is my washing machine) directly to the water heater.

Ironman

At at least one side must be left open to the atmosphere.

eserps89

Im sorry I’m not sure what you mean, 

open to atmosphere? in my mind this tells me to just cut the pipe and leave it open, no cap or ball valve, letting water pour everywhere 

Zman

The pipes going in and out of the tankless coil in the boiler do not share water with the boiler. If you leave them uncapped no water will come out.
Some folks will use the coil as preheat for the water going into the electric heater. That way the boiler does not stay hot in the summer but does help heat the DHW during heating season.

eserps89

So do I need to shut the cold in off to that section of the boiler if it’s separate from the baseboard part of the boiler? 

EBEBRATT-Ed

1.You have cold city water going into the boiler's tank less heater coil. That pipe needs to be disconnected from the coil and run to the cold inlet of the electric water heater (or cap it and pick up a new cold water feed for the electric water heater elsewhere). Leave the cold connection to the coil disconnected...open to the atmosphere.

2.Disconnect the hot water outlet from the tankless heater coil and connect it to the electric hot water heater hot water outlet. This pipe delivers hot water to the fixtures. Leave the hot water outlet from the tank less coil disconnected and open.

3. do not disturb the city water make up to your boiler system.

4. install a vacuum breaker in a tee on the cold water inlet to the electric hot water heater. Mount the vacuum breaker verticle. Put a cold water shut off valve on the cw feeding the electric water heater.

5. Make sure the electric hot water heater has a T & P relief valve
6. Don't power the water heater unless it is full of water and vented

eserps89

That’s very helpful. Thank you very much 

But my one question is a vacuum breaker? 

I have 1/2 pipe with an expansion tank going to the 3/4 flex pipes into the top of the water heater. 

 

Is this vacuum breaker something I can get at Home Depot? Do you possibly have a picture of this item?

I added a picture of my install so far. 

 

STEVEusaPA

Please get a plumber or someone who understands this to give you a hand.

Larry Weingarten

Hello, Others here can verify, but my understanding was that a vacuum breaker is only required in Massachusetts. Looking at your photo, it looks like you ran romex directly to the heater. I think it needs to be in conduit. Flex conduit is fine. A question... why is it plumbed in 1/2" line? Do you have only a few fixtures?

More thoughts... To keep heat from backing up the cold line, I might install a longer flex connector and put a loop in in to act as a heat trap, Also insulating all the hot and the cold line back five feet would be good. I agree with @STEVEusaPA that getting an experienced eye on it would be a good and a safe thing to do. When water heaters misbehave, they can REALLY ruin your day and possibly your life!

Yours, Larry

hot_rod

Most new heaters have heat trapper nipples, ball or flapper type. Feel the pipes when it is hot to see how much migration, keep in mind copper tube does conduct heat.
IPC, at least the 2015 version has this to say about vacuum breakers. How well it is enforced is another question.

ww

I'm looking to install this type of setup but want to have the option to using the boiler and hot water from boiler or water heater and maybe both...i plan on using the water heater in warmer months...

i would get a 40 or 50 gallon water heater. but have read that the electric use is the same so probably a 50...I see the comments on hooking up the water heater and about disconnecting and leaving coil open. I would like to put ball valves somewhere to be able to use either coil in boiler when boiler is used or just hot water heater when boiler is off. the way this is explained i would have to do piping again when hot water heater is off.

the reason for all this is allowing me to be able to think on a new boiler which is oil heat and do concrete work in oil tank area and replace the tank. I don't like to rush. Any suggestions? I have natural gas too but the venting would be a problem due to two different fuel sources into chimney without alot of major things to change. Thanks!

pecmsg

ww said:

I'm looking to install this type of setup but want to have the option to using the boiler and hot water from boiler or water heater and maybe both...i plan on using the water heater in warmer months...

i would get a 40 or 50 gallon water heater. but have read that the electric use is the same so probably a 50...I see the comments on hooking up the water heater and about disconnecting and leaving coil open. I would like to put ball valves somewhere to be able to use either coil in boiler when boiler is used or just hot water heater when boiler is off. the way this is explained i would have to do piping again when hot water heater is off.

the reason for all this is allowing me to be able to think on a new boiler which is oil heat and do concrete work in oil tank area and replace the tank. I don't like to rush. Any suggestions? I have natural gas too but the venting would be a problem due to two different fuel sources into chimney without alot of major things to change. Thanks!

Where are you that electric is cheap?

mattmia2

You can get powered vent gas that vents out the sidewall, although be careful because some have particularly loud inducer blowers.

Gas or electric, the consumption will depend mostly on your consumption of hot water, not the size of the tank or burner/element.

ww

don't use alot of hot water...shower and do dishes...mostly myself...most of these water heaters go on 220...saw some small ones that are 110v...thought gas would be a hassle...i know it's cheaper but more problems in venting...etc....didn't say electric was cheap...it seems this is the best option here..nyc.

pecmsg

ww said:

don't use alot of hot water...shower and do dishes...mostly myself...most of these water heaters go on 220...saw some small ones that are 110v...thought gas would be a hassle...i know it's cheaper but more problems in venting...etc....didn't say electric was cheap...it seems this is the best option here..nyc.

Get a oil Fired Heater

Jamie Hall

Well, electric will be your most expensive option to run. What you have read is, fundamentally, correct -- the size of the heater doesn't make much i any difference to the amount of electricity you use, unless the heater is so small you constantly run out and thus take cold showers.

I believe there may be a moratorium on new gas hookups in New York, so that option is probably out.

The oil fired hot water heater will be more expensive to buy -- but a lot less expensive to run, and wihile it won't be unlimited hot water, a 32 gallon should give you more than you'd ever use.

STEVEusaPA

A small indirect would be cheaper in the long run.

EBEBRATT-Ed

@ww

To answer your question most electric water heaters have 4500 watt elements (that's the most common size) regardless of the tank size. So a 40 gallon or 50 gallon use the same power. But the 50 will hold more water so ther is some extra standby loss when the tank is sitting there full of hot water.

If you have gas available that is always a better option , direct vent and power vent through the side wall.

You can pipe the water heater in parallel with the tankless coil with valves (run one or the other). When you switch over you have to drain the tankless coil because if the boiler runs for heat it would build up pressure in the coil. And make sure to kill the power to the electric water heater when it is not used. I don't like that set up because a tank full of cold or luke warm water is not good. Leagonaires

I would use both. Pipe the tankless coil over to the water heater and use the tankless to heat the tank. You will need a bronze circulator and a few controls to do this

Keep the electric power to the tank on. It will only power the electric heaters if the tankless can't keep up.

In the summer when the boiler is off shut of the circulator and drain the piping and tankless coil. Otherwise you could build up pressure in the coil if the boiler runs with the water lines valved off

ww

ok....will look at this...just remember those suggesting indirect....and oil fired water heaters...they are great options...but i will have to remove the oil tank...and may change boiler..and doing concrete and structural work in oil tank storage area.. could take me quite awhile..hence the need for a water heater....for quite a few months..don't know how much the water heater will use in electric but with limited use will see ...figure won't use a lot since i don't plan on using alot of hot water. with the amounts of electrical use on these energy labels i imagine they go down when not a lot of water is used?

as far as the piping i understand what you are saying....and the fact about the stagnant water in the pipes.
if it wasn't for the venting issues... i would rather have gas...since i have gas in the house already...and also some capped off gas lines as well...it's alot cheaper and don't have to run a 10 gauge armored cable to the water heater with a 30 amp breaker...but there are always roadblocks

ww

i'll be looking at gathering some more info on venting through the side wall...believe i looked at that before and it said i needed a high efficiency water heater...will see about that one...because i have over 8 inch solid concrete wall to go thru.

delta T

As to the code requirement for a vacuum breaker, in my neck of the woods (CO, IPC 2018) unless the water heater is located above the fixtures, you do not need a vacuum breaker on anything other than a bottom fed water heat. If it is top fed and not above a fixture, then no vacuum breaker required. Your codes may differ locally.

mattmia2

Perhaps an electric water heater hooked up as just electric during your renovations then hooked up with a tankless coil in the boiler to heat it once the boiler is replaced is your best option this time around followed by an indirect when that tank fails. You will need a 50 gallon minimum for a shower, more if you take hotter showers, have a higher flow shower head, have colder incoming water in the winter, if you take longer showers, etc.

ww

these are all great points ...i know how cold this water is here...tested a few times....sometimes 40 degrees when checked.