# Thread: how many amps does a water heater draw

1. Regular Member
Join Date
Apr 2008
Location
Upstate New York
Posts
800
Post Likes

## how many amps does a water heater draw

I have a 220 volt water heater with I believe a 1500 watt elements, how many amps does it draw ?? Its on a 30amp breaker

2. Amps x Volts = Watts

Watts / Volts = Amps

1500 / 220 = 6.8

3. Professional Member*
Join Date
Feb 2011
Location
North East Ohio
Posts
825
Post Likes
1500/220=6.8 amps (I think) How many elements?

4. Regular Member
Join Date
Jul 2007
Location
Mount Airy, MD
Posts
7,303
Post Likes
Originally Posted by NCHeat
1500/220=6.8 amps (I think) How many elements?
Typically there are 2 but, the top one is the priority and the bottom is the second priority. They are staged/selected as such via the upper stat

5. Regular Member
Join Date
Apr 2008
Location
Upstate New York
Posts
800
Post Likes
opps read it wrong, it says on the label 4500 at 240 volts so what is it at 220 volts watts and amps ?? It has two elements but only one runs at a time

6. Professional Member*
Join Date
Feb 2011
Location
North East Ohio
Posts
825
Post Likes
Originally Posted by Chris_Worthington
Typically there are 2 but, the top one is the priority and the bottom is the second priority. They are staged/selected as such via the upper stat
Thanks Chris

7. Professional Member*
Join Date
Feb 2011
Location
North East Ohio
Posts
825
Post Likes
Originally Posted by cvcman
opps read it wrong, it says on the label 4500 at 240 volts so what is it at 220 volts watts and amps ?? It has two elements but only one runs at a time
20.45

8. Regular Member
Join Date
Jul 2007
Location
Mount Airy, MD
Posts
7,303
Post Likes
Originally Posted by cvcman
opps read it wrong, it says on the label 4500 at 240 volts so what is it at 220 volts watts and amps ?? It has two elements but only one runs at a time
Did ya happen to catch Ed's post??

9. Regular Member
Join Date
Apr 2008
Location
Upstate New York
Posts
800
Post Likes
yea i saw Ed's but again I have 220 volts not 240 like label says for 4500 watts

10. Regular Member
Join Date
Jul 2007
Location
Mount Airy, MD
Posts
7,303
Post Likes
Originally Posted by cvcman
yea i saw Ed's but again I have 220 volts not 240 like label says for 4500 watts
The formulas that Ed gave would the same for anything that is a constant load (Inductive Load) to include light bulbs

11. Regular Member
Join Date
Jul 2007
Location
Mount Airy, MD
Posts
7,303
Post Likes
Watts / Volts = Amps

4500/220 = Chris to lazy to calculate this for you

12. New Guest
Join Date
Jun 2007
Posts
2
Post Likes
P=VI
I=P/V 4500/240=18.7 amps
V=IR
R=V/I 240/18.7=12.8 ohms
I=V/R 220/12.8=17.1 amps
P=VI 220*17.1=3751 watts

13. Regular Member
Join Date
Jul 2007
Location
Mount Airy, MD
Posts
7,303
Post Likes
Originally Posted by heathkit
P=VI
I=P/V 4500/240=18.7 amps
V=IR
R=V/I 240/18.7=12.8 ohms
I=V/R 220/12.8=17.1 amps
P=VI 220*17.1=3751 watts
Always nice to see someone with a calculator handy

And BTW, welcome to the site

Page 1 of 2 12 Last

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•

## Related Forums

The place where Electrical professionals meet.