I have an electric water heater (40 Gallon) that is hooked to 120V. 240V is
run to a shut off switch (fused) just above the heater (3 feet away) but for
some reason the installer ran 120 to the heater (black and white wires, the
red is disconnected, and yes I can measure voltage). The main fuse panel has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If I did
this what would the fuse size in the panel need to be?

I'd want a really good look at the water heater serial number plate, and
also the elements. Makes me wonder if someone installed 115 volt elements.
Were they the lower voltage, then 220 VAC would likely blow the elements.

Wattage equals volts times amps. If you're doubling the voltage, you should
need half the amperage. Fuses are measured in amps.

There is no cost saving, you pay by the watt. (actually by the kilowatt
hour).

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.org
..
..

"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V. 240V is
run to a shut off switch (fused) just above the heater (3 feet away) but for
some reason the installer ran 120 to the heater (black and white wires, the
red is disconnected, and yes I can measure voltage). The main fuse panel has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If I did
this what would the fuse size in the panel need to be?

Read the other responses to your question as they provide some good insight.

If you have 120 volts powering 240 volt elements, it must take several hours
for you to get warm water. There is a lot of resistance in those elements
and hot water seems unlikely at 120 volts.



"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V. 240V
is
run to a shut off switch (fused) just above the heater (3 feet away) but
for
some reason the installer ran 120 to the heater (black and white wires,
the
red is disconnected, and yes I can measure voltage). The main fuse panel
has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If I
did
this what would the fuse size in the panel need to be?

Read the other responses to your question as they provide some good insight.

If you have 120 volts powering 240 volt elements, it must take several hours
for you to get warm water. There is a lot of resistance in those elements
and hot water seems unlikely at 120 volts.



"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V. 240V
is
run to a shut off switch (fused) just above the heater (3 feet away) but
for
some reason the installer ran 120 to the heater (black and white wires,
the
red is disconnected, and yes I can measure voltage). The main fuse panel
has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If I
did
this what would the fuse size in the panel need to be?

I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under 3000
watts (2880) and since only one is on at a time.....the math works out.

On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

As I said the water is fine once it is heated up but if I do use it up...it
takes much of the day to get it back....estimate 4 to 5 hours. This doesn't
happen very often since there are only 2 people living here most of the
time.

I am not sure if there would be any reason to hook up 120 vice 240. It works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years ago.

So to recap, If I do revert to 240v the wire size must be 10 guage and there
must be 30 amp fuses?

Thanks for all the help and the quick replies.It's piquing my curiosity more
than anything.

Bob

"John Grabowski" wrote in message
. net...
Read the other responses to your question as they provide some good
insight.

If you have 120 volts powering 240 volt elements, it must take several
hours
for you to get warm water. There is a lot of resistance in those elements
and hot water seems unlikely at 120 volts.



"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V. 240V
is
run to a shut off switch (fused) just above the heater (3 feet away) but
for
some reason the installer ran 120 to the heater (black and white wires,
the
red is disconnected, and yes I can measure voltage). The main fuse panel
has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If I
did
this what would the fuse size in the panel need to be?

I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under 3000
watts (2880) and since only one is on at a time.....the math works out.

On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

As I said the water is fine once it is heated up but if I do use it up...it
takes much of the day to get it back....estimate 4 to 5 hours. This doesn't
happen very often since there are only 2 people living here most of the
time.

I am not sure if there would be any reason to hook up 120 vice 240. It works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years ago.

So to recap, If I do revert to 240v the wire size must be 10 guage and there
must be 30 amp fuses?

Thanks for all the help and the quick replies.It's piquing my curiosity more
than anything.

Bob

"John Grabowski" wrote in message
. net...
Read the other responses to your question as they provide some good
insight.

If you have 120 volts powering 240 volt elements, it must take several
hours
for you to get warm water. There is a lot of resistance in those elements
and hot water seems unlikely at 120 volts.



"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V. 240V
is
run to a shut off switch (fused) just above the heater (3 feet away) but
for
some reason the installer ran 120 to the heater (black and white wires,
the
red is disconnected, and yes I can measure voltage). The main fuse panel
has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If I
did
this what would the fuse size in the panel need to be?

In article , "Bob" wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under 3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it up...it
takes much of the day to get it back....estimate 4 to 5 hours. This doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years ago.

Obviously an installation error -- whoever installed it had no clue what he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements, hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

In article , "Bob" wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under 3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it up...it
takes much of the day to get it back....estimate 4 to 5 hours. This doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years ago.

Obviously an installation error -- whoever installed it had no clue what he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements, hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?


"Doug Miller" wrote in message
.com...
In article , "Bob"
wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under
3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years
ago.

Obviously an installation error -- whoever installed it had no clue what
he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements,
hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?


"Doug Miller" wrote in message
.com...
In article , "Bob"
wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under
3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years
ago.

Obviously an installation error -- whoever installed it had no clue what
he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements,
hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

In article , "Bob" wrote:
When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

It's been a long time since I've had an electric water heater in a house I've
owned, so I could be wrong, but I don't think that's correct.


The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?

For the third time, YES. The installer was incompetent. It's *supposed* to be
connected to a 240V source. Think about it, man: you said yourself that the
recovery time is 4 or 5 hours. That's absurdly long, even for an electric
water heater. Doesn't that tell you that something is *wrong* ? What possible
reason could there be for doing that deliberately? Why would anyone *want* to
wait five hours for the water to warm up again?


"Doug Miller" wrote in message
y.com...
In article , "Bob"
wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under
3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years
ago.

Obviously an installation error -- whoever installed it had no clue what
he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements,
hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)



--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

In article , "Bob" wrote:
When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

It's been a long time since I've had an electric water heater in a house I've
owned, so I could be wrong, but I don't think that's correct.


The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?

For the third time, YES. The installer was incompetent. It's *supposed* to be
connected to a 240V source. Think about it, man: you said yourself that the
recovery time is 4 or 5 hours. That's absurdly long, even for an electric
water heater. Doesn't that tell you that something is *wrong* ? What possible
reason could there be for doing that deliberately? Why would anyone *want* to
wait five hours for the water to warm up again?


"Doug Miller" wrote in message
y.com...
In article , "Bob"
wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under
3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years
ago.

Obviously an installation error -- whoever installed it had no clue what
he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements,
hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)



--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

On Fri, 15 Aug 2003 02:28:49 GMT, (Doug Miller)
wrote:

In article , "Bob" wrote:
When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

It's been a long time since I've had an electric water heater in a house I've
owned, so I could be wrong, but I don't think that's correct.


That is so. It heats the one end first (the top IIRC), then the other
end when it reaches temperature.

The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?

For the third time, YES. The installer was incompetent. It's *supposed* to be
connected to a 240V source. Think about it, man: you said yourself that the
recovery time is 4 or 5 hours. That's absurdly long, even for an electric
water heater. Doesn't that tell you that something is *wrong* ? What possible
reason could there be for doing that deliberately? Why would anyone *want* to
wait five hours for the water to warm up again?


"Doug Miller" wrote in message
gy.com...
In article , "Bob"
wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under
3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years
ago.

Obviously an installation error -- whoever installed it had no clue what
he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements,
hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

On Fri, 15 Aug 2003 02:28:49 GMT, (Doug Miller)
wrote:

In article , "Bob" wrote:
When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

It's been a long time since I've had an electric water heater in a house I've
owned, so I could be wrong, but I don't think that's correct.


That is so. It heats the one end first (the top IIRC), then the other
end when it reaches temperature.

The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?

For the third time, YES. The installer was incompetent. It's *supposed* to be
connected to a 240V source. Think about it, man: you said yourself that the
recovery time is 4 or 5 hours. That's absurdly long, even for an electric
water heater. Doesn't that tell you that something is *wrong* ? What possible
reason could there be for doing that deliberately? Why would anyone *want* to
wait five hours for the water to warm up again?


"Doug Miller" wrote in message
gy.com...
In article , "Bob"
wrote:
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under
3000
watts (2880) and since only one is on at a time.....the math works out.

Yep. But what do you mean "since only one is on at a time" ?


On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.

No, that means it's supposed to be connected to a 240V source, not 120V.


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

It'll heat up a *lot* faster if it's connected to the correct source.

I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years
ago.

Obviously an installation error -- whoever installed it had no clue what
he
was doing.

So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

240V across 20 ohms is a current of 12 amps. But you have two elements,
hence
24 amps total. Therefore, yes, you need 10ga wire and 30 amp fuses or
breakers.


--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)

"Bob" wrote in message
...
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

Then its wrong.



I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under 3000
watts (2880) and since only one is on at a time.....the math works out.

On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.


Wrong. Thats the operational voltage....meaning...you have a 220-240VAC
heater...meaning...you have only one leg to it...


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

Umm...I have one that takes about 15 minutes to recover when all the stored
hot water is used up.....and its a 40 gallon tank...but..its hooked up
correctly....


I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years ago.


Its not really working...
Its barely working.


So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

Thanks for all the help and the quick replies.It's piquing my curiosity
more
than anything.

Bob

"John Grabowski" wrote in message
. net...
Read the other responses to your question as they provide some good
insight.

If you have 120 volts powering 240 volt elements, it must take several
hours
for you to get warm water. There is a lot of resistance in those
elements
and hot water seems unlikely at 120 volts.



"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V.
240V
is
run to a shut off switch (fused) just above the heater (3 feet away)
but
for
some reason the installer ran 120 to the heater (black and white
wires,
the
red is disconnected, and yes I can measure voltage). The main fuse
panel
has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If
I
did
this what would the fuse size in the panel need to be?

"Bob" wrote in message
...
When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?

For this water heater it will draw 12.5A at 240V so you only require a 20A
circuit. The smallest element I've ever heard of in a 240V model was 3600W,
but even that will fit on a 20A circuit. I have a 5500W model, and that
requires a 30A circuit. Water heater circuits must have an ampacity of 125%
of the nameplate amp rating. If you have wires for a 30A circuit (i.e. 10ga
copper), you can porbably install any replacement residential heater that
you want. A 20A circuit will limit you to the ones with smaller elements.

The only reason I can think of someone would have done this was to "save
energy". However, you will end up using the same amount of electricity to
heat the tank back up. You only save when cold water starts coming out of
the shower so you have to get out. Perhaps the previous owner had a person
who liked to take forever hot showers and got tired of paying for it.
Although a properly wired 20 gallon model would probably cure that too and
allow another shower in 15 minutes.

--
Mark
Kent, WA

"Bob" wrote in message
...
I did measure across the 2 input wires at the upper limit switch on the
water heater (it's a 2 wire system) and did read 120v.

Then its wrong.



I am pretty sure the wire is 10 guage but I will verify that.

The elements are 3000 watt and read 20 ohms. By my calculation (it's been
awhile but i think I remember) 240 volts across 20 ohms is just under 3000
watts (2880) and since only one is on at a time.....the math works out.

On the side of the heater it does state 240v but I believe this to be a
maximum applied voltage only.


Wrong. Thats the operational voltage....meaning...you have a 220-240VAC
heater...meaning...you have only one leg to it...


As I said the water is fine once it is heated up but if I do use it
up...it
takes much of the day to get it back....estimate 4 to 5 hours. This
doesn't
happen very often since there are only 2 people living here most of the
time.

Umm...I have one that takes about 15 minutes to recover when all the stored
hot water is used up.....and its a 40 gallon tank...but..its hooked up
correctly....


I am not sure if there would be any reason to hook up 120 vice 240. It
works
obviously other than the recovery time. Any ideas other than installation
error? It was installed 2 years before we moved in, which was 2 years ago.


Its not really working...
Its barely working.


So to recap, If I do revert to 240v the wire size must be 10 guage and
there
must be 30 amp fuses?

Thanks for all the help and the quick replies.It's piquing my curiosity
more
than anything.

Bob

"John Grabowski" wrote in message
. net...
Read the other responses to your question as they provide some good
insight.

If you have 120 volts powering 240 volt elements, it must take several
hours
for you to get warm water. There is a lot of resistance in those
elements
and hot water seems unlikely at 120 volts.



"Bob" wrote in message
...
I have an electric water heater (40 Gallon) that is hooked to 120V.
240V
is
run to a shut off switch (fused) just above the heater (3 feet away)
but
for
some reason the installer ran 120 to the heater (black and white
wires,
the
red is disconnected, and yes I can measure voltage). The main fuse
panel
has
2, 15 amp fuses for the circuit.

I was thinking of changing the water heater to 240v for the purpose of
quicker recovery time. Is there a reason the person used only 120V? If
I
did
this what would the fuse size in the panel need to be?

"Bob" wrote in message
...
When I say "only one is on at a time" , I mean only one element in an
electric water heater is on at any given time. This I am sure of.

The label states "maximum allowable rating" and states "240V" with 2 "3000
watt elements factory installed"

And I agree..it will heat up alot faster (4 times faster) with 240v vice
120v but is the only reason it would be hooked up to 120v is that the
installer didn't have a clue?

For this water heater it will draw 12.5A at 240V so you only require a 20A
circuit. The smallest element I've ever heard of in a 240V model was 3600W,
but even that will fit on a 20A circuit. I have a 5500W model, and that
requires a 30A circuit. Water heater circuits must have an ampacity of 125%
of the nameplate amp rating. If you have wires for a 30A circuit (i.e. 10ga
copper), you can porbably install any replacement residential heater that
you want. A 20A circuit will limit you to the ones with smaller elements.

The only reason I can think of someone would have done this was to "save
energy". However, you will end up using the same amount of electricity to
heat the tank back up. You only save when cold water starts coming out of
the shower so you have to get out. Perhaps the previous owner had a person
who liked to take forever hot showers and got tired of paying for it.
Although a properly wired 20 gallon model would probably cure that too and
allow another shower in 15 minutes.

--
Mark
Kent, WA