Is my panel sufficient to add Electric water heater

andy

Hi there.

can anybody help me out on this. I do not know much about electric.
I am planing to replace my gas water heater with an electric one. The first thing I need to do is see if my current electric panel has enough capacity, right? Sorry for the dumb question, but how do I check that (exact steps)? From what I am reading most electric water heaters need hard wired 240V line from the panel.
So how do I go about checking if my electric service panel is adequate? Would I need just 2 circuit breakers, etc?

Appreciate any help.

thank you

Scuba_Dave

What is you currecnt electric service 100a 200a ?
What other 240v electric devices do you have?
Other electric in use?
Have you done a whole house demand calc ?

andy

hi scuba dave,

the only other things I have that use 240v are dryer, stove/range, and furnace. I am guessing they all use 240v. I can't think of anything else.
Sorry for the dump question. How do I check with my service is 100 or 200 amps?

thank you

Grampa Bud

As much as I don't like my gas company I just have to ask, why do you want to change from gas to electric?? Electric has horrendous recovery times compared even to propane and propane is far inferior to natural gas.

andy

well the answer has many reasons.

One is that I had to get rid of my old chimney that only gas water heater was venting to. I have read that you cannot vent those gas water heaters through the outside wall of your house horizontally, it has to go up the roof, unless it is a power vent (direct vent) gas water heater, which can vent horizontally through the outside wall of the house. So basically instead of going through all this nightmare with venting, I thought I would get a new electric water heater, which is cheaper than gas to buy (the unit itself).

I guess the very last reason is that gas is much more expensive than electric now..yes I know it might all change next year

Anyway..I guess these are my reasons with venting being #1.

Thank you

Scuba_Dave

There should be a main breaker somewhere
Either in the panel or somewhere else
It will have a stamped number on it, 60a 100a 200a etc

There are several residential Load calcs that you can use
I don't have a link to the one I used

andy

thanks scuba dave. I will check whether I have 100 or 200a service when I get home. I hope I have 200. If I have 100 than you pretty sure I am doomed to upgrade to 200 before installing electric water heater? Or you think it can still carry water heater and all the other 240V things I mentioned on 100a?

If I have to upgrade to 200a,. do you know the approximate cost?

thanks

Scuba_Dave

Cost to upgrade can vary widely

What method of heating is your furnace?
Usually this is only 120v to run a pump, fan etc unless electric heat

I had 100a at my last house & I switched my stove to gas to free up enough power for a hot tub & AC. Priorities

andy

hehe
I have a gas furnace and centrail air for AC (I guess I should have mentioned that that probably runs on 240v as well?)

Grampa Bud

Hey Andy and Dave I was paying attention. On another thread when Dave headed down this same road I goofed up not Dave, but here's a website that Dave and the other guys said to use for load calcs. http://www.selfhelpandmore.com/home-...ation-2002.php Also many power vent water heaters that vent out the side wall of a home use schedule 40 PVC and are a snap to put in.

andy

scuba dave,

I checked my service panel. Well it is 100a and it appears I have 2 circuit breakers free one on the left leg another on the right leg. Do you think an electic water heater can hang on one circuit breaker?

thanks

andy

thanks grampa bud. Sorry, your link does not seem to be working.
On the other hand, power vent water heater I guess is another way to go for me. The only problem with those, they are 2-3 times more expensive than electric water heaters However, if I need to upgrade my electric service in order to get el wh, than I might as well consider gas power vent wh.

thank you

Jim Port

You would need 2 breaker spaces. Most of the time these need to be one above the other. You should be able to move a single pole breaker to the other side to free up the space needed.

thefamouscbc

You have to have two circuits free together. You can use a tandem breaker on one of your single pole circuits to free up some space.

If you already are running three or four other 240v circuits on your house plus going to add another with the water heater, the 100amp panel is pushing your load.

When you figure out if the service will hold the extra 240v circuit, you will need to pull a 10/3 NMB with ground to where the new water heater is going. They are usually orange. Just tell the supply house exactly 10/3 Romex with ground. You will need to sleeve it coming out of the wall too. I usually use greenfield 1/2" with a 1/2" greenfield 90 going into the heater. http://www.foxelectricsupply.com/con...oductNo=ARL851

If you need step by step instructions you can pm me anytime.

Scuba_Dave

They are possibly working on the site
The load calc isn't there....just went & checked
And I can't upload mine as it is an excel spreadsheet

Here is one, I tested VS my spreadsheet & it is approx the same

http://www.mikeholt.com/documents/ca...lculations.xls

My 50g electric water heater runs on 4500w heaters, two of them that are not on at the same time = 37.5a
It's a fairly big increase on a 100a panel