I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt

On Jan 3, 1:06�pm, Newton wrote:
I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt


why not buy a 100 gallon tank? it will save energy by 1/2 the standby
losses

why not buy a 100 gallon tank? it will save energy by 1/2 the standby
losses

That's a thought.
Actually, the 75 has been more than adequate for my needs, so another
75 would do me just fine

The reason I was looking at two 50s was mainly because they would be
easier for me to get down the steps into the basement. The existing
one was put in by professionals, so they had ample manpower to
manhandle it down the steps. I have learned to plumb in the time
since that installation.

I asked a plumber once about using two 40s, but he suggested that if
two 50s fit, then I should go for 2 50s.

Also, on a scouting trip to Home Depot, I did not see any 75s.
Can these be had other than by going through a plumber?
I'm not sure if the local plumbing supply place sells HWHs to DIYers.
It's pretty much a wholesale place.

Finally (and least important) I was thinking that with two heaters,
aprropriately plumbed, if one failed, I could bypass it, thus taking
the "emergency" out of any failure scenario.

Newt

On Jan 3, 12:06*pm, Newton wrote:
I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt


Get a high output single tank. When you shop buy with comparing by EF
Energy Factor rating, most of what you get is 55-65 EF on standard
tanks so at best 35 cents of ever dollar is wasted, 2 tanks is not
smart. Your old tank may never of had the btu to keep up. You would
want a faster recovery. www.energystar.gov has ratings on all tanks,
there are higher efficency tanks to also consider. AO Smith has a
good commercial line.

On Jan 3, 1:36*pm, Newton wrote:
why not buy a 100 gallon tank? it will save energy by 1/2 the standby
losses

That's a thought.
Actually, the 75 has been more than adequate for my needs, so another
75 would do me just fine

The reason I was looking at two 50s was mainly because they would be
easier for me to get down the steps into the basement. *The existing
one was put in by professionals, so they had ample manpower to
manhandle it down the steps. *I have learned to plumb in the time
since that installation.

I asked a plumber once about using two 40s, but he suggested that if
two 50s fit, then I should go for 2 50s.

Also, on a scouting trip to Home Depot, I did not see any 75s.
Can these be had other than by going through a plumber?
I'm not sure if the local plumbing supply place sells HWHs to DIYers.
It's pretty much a wholesale place.

Finally (and least important) I was thinking that with two heaters,
aprropriately plumbed, if one failed, I could bypass it, thus taking
the "emergency" out of any failure scenario.

Newt

Get a high output 50 so you can move it. HD stuff is not the good
stuff.

On Jan 3, 1:06?pm, Newton wrote:
I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this one
http://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour rating
http://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unit
http://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

On Jan 3, 4:40*pm, "Ed Pawlowski" wrote:
On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. *That would include
two of the same type. *.

What kind of heat do you have? *If you have a hot water boiler, consider
adding an indirect fired water heater. *My 40 gallon has a first hour rating
of over 230 gallons. *You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. *Two of them *if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org *Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.


It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.

On Jan 3, 3:40*pm, "Ed Pawlowski" wrote:
On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. *That would include
two of the same type. *.

What kind of heat do you have? *If you have a hot water boiler, consider
adding an indirect fired water heater. *My 40 gallon has a first hour rating
of over 230 gallons. *You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. *Two of them *if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org *Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

Do you mean a furnace-boiler and water heater cannot share a chimney,
Its code here.

On Jan 3, 5:19�pm, Newton wrote:
On Jan 3, 4:40�pm, "Ed Pawlowski" wrote:





On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. �That would include
two of the same type. �.

What kind of heat do you have? �If you have a hot water boiler, consider
adding an indirect fired water heater. �My 40 gallon has a first hour rating
of over 230 gallons. �You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. �Two of them �if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er..com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org �Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. �Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement and old one out

On Jan 3, 5:19�pm, Newton wrote:
On Jan 3, 4:40�pm, "Ed Pawlowski" wrote:





On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. �That would include
two of the same type. �.

What kind of heat do you have? �If you have a hot water boiler, consider
adding an indirect fired water heater. �My 40 gallon has a first hour rating
of over 230 gallons. �You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. �Two of them �if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er..com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org �Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. �Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

heard of people with no power no heat running a garden hhose thru
home, ending at tub, running slowly hot water to provide minimum heat.

lack of power for 3 days motivated me to buy a 1000 watt inverter and
3 older back up generators

On Jan 3, 9:20*pm, " wrote:
On Jan 3, 5:19 pm, Newton wrote:





On Jan 3, 4:40 pm, "Ed Pawlowski" wrote:

On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement *and old one out- Hide quoted text -

- Show quoted text -

Thank you for info about special orders at Lowes and Home Depot.
I did not know this.
Also thanks for info about BTU's. I did not know this either.

I will go to "big boxes" Monday to see what they can offer me.

Thanks again.

"ransley" wrote in message

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .



Do you mean a furnace-boiler and water heater cannot share a chimney,
Its code here.
************************************************** *****

My old house had both too, very common. I recall recently that it is no
longer allowed, but I don't have any firm information. It may have been a
local code. I know that woodstoves and oil/gas burners are not allowed.
I've not had any reason to check so I'm not up to date on that.

On Jan 3, 1:06*pm, Newton wrote:
I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt


For the cost of doing that, you could get a nice tankless hot water
heater. Then there would be no capacity issue and you could easily
get it down the stairs.

On Jan 3, 8:20*pm, " wrote:
On Jan 3, 5:19 pm, Newton wrote:





On Jan 3, 4:40 pm, "Ed Pawlowski" wrote:

On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement *and old one out- Hide quoted text -

- Show quoted text -

You do mean your 50 HO model is no longer made, I hope. 40 and 50 gal
HO tanks are common if you look, talk HO I have an 90 gallon with
about 180,000 btu input. HD wont have quality, efficency or the real HO

On Jan 3, 8:52*pm, "Ed Pawlowski" wrote:
"ransley" wrote in message

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

Do you mean a furnace-boiler and water heater cannot share a chimney,
Its code here.
************************************************** *****

My old house had both too, very common. I recall recently that it is no
longer allowed, but I don't have any firm information. It may have been a
local code. *I know that woodstoves and oil/gas burners are not allowed..
I've not had any reason to check so I'm not up to date on that.

It may not be new code now, but they wont make you change it in
Chicago on even commercial apartments, I just passed an inspection.

On Jan 3, 8:26*pm, Newton wrote:
On Jan 3, 9:20*pm, " wrote:





On Jan 3, 5:19 pm, Newton wrote:

On Jan 3, 4:40 pm, "Ed Pawlowski" wrote:

On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement *and old one out- Hide quoted text -

- Show quoted text -

Thank you for info about special orders at Lowes and Home Depot.
I did not know this.
Also thanks for info about BTU's. *I did not know this either.

I will go to "big boxes" Monday to see what they can offer me.

Thanks again.- Hide quoted text -

- Show quoted text -

Shop online and compare at www.energystar.gov for facts, you wont
get the truth from HD. AO Smith, Rheem are better companies with
inovation and commercial quality if you want it, like 4x6" scale
cleanout panels, condensing. Shop EF to save

On Jan 3, 10:16*pm, Pat wrote:
On Jan 3, 1:06*pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt


For the cost of doing that, you could get a nice tankless hot water
heater. *Then there would be no capacity issue and you could easily
get it down the stairs.

I have a Ng tankless and wont put in a tank again, but here its like
convincing folk their V8 car gets crap milage, they give you 100
reasons they want another V8.

On Sat, 3 Jan 2009 14:19:18 -0800 (PST), Newton
wrote:

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

AOSmith is good, but so is Bradford White if you end up hiring a
plumber to do the job. Ours is serving us well and vents up the
chimney.

On Jan 4, 5:17�am, ransley wrote:
On Jan 3, 8:26�pm, Newton wrote:





On Jan 3, 9:20�pm, " wrote:

On Jan 3, 5:19 pm, Newton wrote:

On Jan 3, 4:40 pm, "Ed Pawlowski" wrote:

On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa..org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement �and old one out- Hide quoted text -

- Show quoted text -

Thank you for info about special orders at Lowes and Home Depot.
I did not know this.
Also thanks for info about BTU's. �I did not know this either.

I will go to "big boxes" Monday to see what they can offer me.

Thanks again.- Hide quoted text -

- Show quoted text -

Shop online and compare at �www.energystar.gov� for facts, you wont
get the truth from HD. AO Smith, Rheem are better companies with
inovation and commercial quality if you want it, like 4x6" scale
cleanout panels, condensing. Shop EF to save- Hide quoted text -

- Show quoted text -

hey ransley you post this link often, but theres no water heateing
listed, as stand alone devices.

please explain?

On Jan 4, 5:22�am, ransley wrote:
On Jan 3, 10:16�pm, Pat wrote:





On Jan 3, 1:06�pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt


For the cost of doing that, you could get a nice tankless hot water
heater. �Then there would be no capacity issue and you could easily
get it down the stairs.

I have a Ng tankless and wont put in a tank again, but here its like
convincing folk their V8 car gets crap milage, they give you 100
reasons they want another V8.- Hide quoted text -

- Show quoted text -

nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.

regular tanks tend to be install and forget till they leak

On Jan 4, 5:10�am, ransley wrote:
On Jan 3, 8:20�pm, " wrote:





On Jan 3, 5:19 pm, Newton wrote:

On Jan 3, 4:40 pm, "Ed Pawlowski" wrote:

On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa.org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement �and old one out- Hide quoted text -

- Show quoted text -

You do mean your 50 HO model is no longer made, I hope. 40 and 50 gal
HO tanks are common if you look, talk HO I have an 90 gallon with
about 180,000 btu input. HD wont have quality, efficency or the real HO- Hide quoted text -

- Show quoted text -

I checked several sources including the last real plumbing supply
place around here all report 50 gallon 75,000 BTU tanks are no longer
made. Want the higher output? Go with 75 gallons.

Its a fit issue for me and why I havent replaced the tank on my normal
schedule.

Other things must be moved to make room

On Sun, 4 Jan 2009 07:17:12 -0800 (PST), "
wrote:

nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.


Actually Bob, tankless can be serviced by a DIYer. Power failure is
not a problem. My fake fire place can be lit with a match if the
low-voltage has failed. Same with a gas tankless heater.

regular tanks tend to be install and forget till they leak

See: http://www.tanklesswaterheaterguide.com/

Okay you hate tankless

On Jan 4, 8:41�pm, Oren wrote:
On Sun, 4 Jan 2009 07:17:12 -0800 (PST), "

wrote:
nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.

Actually Bob, �tankless can be serviced by a DIYer. Power failure is
not a problem. My fake fire place can be lit with a match if the
low-voltage has failed. Same with a gas tankless heater.

regular tanks tend to be install and forget till they leak

See:http://www.tanklesswaterheaterguide.com/

Okay you hate tankless

a power vent tankless can NOT be lighted with a match to operate
during a power failure!

On Sun, 4 Jan 2009 19:09:51 -0800 (PST), "
wrote:

On Jan 4, 8:41?pm, Oren wrote:
On Sun, 4 Jan 2009 07:17:12 -0800 (PST), "

wrote:
nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.

Actually Bob, ?tankless can be serviced by a DIYer. Power failure is
not a problem. My fake fire place can be lit with a match if the
low-voltage has failed. Same with a gas tankless heater.

regular tanks tend to be install and forget till they leak

See: http://www.tanklesswaterheaterguide.com/

Okay you hate tankless

a power vent tankless can NOT be lighted with a match to operate
during a power failure!

Not all tankless heaters have power vents, right? Do you know?

On Jan 4, 10:38�pm, Oren wrote:
On Sun, 4 Jan 2009 19:09:51 -0800 (PST), "





wrote:
On Jan 4, 8:41?pm, Oren wrote:
On Sun, 4 Jan 2009 07:17:12 -0800 (PST), "

wrote:
nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.

Actually Bob, ?tankless can be serviced by a DIYer. Power failure is
not a problem. My fake fire place can be lit with a match if the
low-voltage has failed. Same with a gas tankless heater.

regular tanks tend to be install and forget till they leak

See:http://www.tanklesswaterheaterguide.com/

Okay you hate tankless

a power vent tankless can NOT be lighted with a match to operate
during a power failure!

Not all tankless heaters have power vents, right? Do you know?- Hide quoted text -

- Show quoted text -

Your really minimizing the number of availble models by saying no
power vent.

many larger BTU units are direct power vent. normal chimneys may be
too small for a high BTU tankless

The number of overall constraints make the tankless a real adjustment
and hard to live with.

Like buying a tiny car to save gasoline when your 6 foot 4 and 250
pounds.

Sure you can buy it, but will you be happy with your purchase?

On Jan 4, 9:09*pm, " wrote:
On Jan 4, 8:41 pm, Oren wrote:





On Sun, 4 Jan 2009 07:17:12 -0800 (PST), "

wrote:
nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.

Actually Bob, tankless can be serviced by a DIYer. Power failure is
not a problem. My fake fire place can be lit with a match if the
low-voltage has failed. Same with a gas tankless heater.

regular tanks tend to be install and forget till they leak

See:http://www.tanklesswaterheaterguide.com/

Okay you hate tankless

a power vent tankless can NOT be lighted with a match to operate
during a power failure!- Hide quoted text -

- Show quoted text -

Mine has battery ignition, there are models with Hydro power.

On Jan 4, 10:41*am, " wrote:
On Jan 4, 5:10 am, ransley wrote:





On Jan 3, 8:20 pm, " wrote:

On Jan 3, 5:19 pm, Newton wrote:

On Jan 3, 4:40 pm, "Ed Pawlowski" wrote:

On Jan 3, 1:06?pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

AFAIK, two appliances are not allowed on one chimney. That would include
two of the same type. .

What kind of heat do you have? If you have a hot water boiler, consider
adding an indirect fired water heater. My 40 gallon has a first hour rating
of over 230 gallons. You can go with a direct vent model, such as this onehttp://www.ho****er.com/lit/spec/res_gas/AOSRG45101.pdf
It will give you 164 gallons first hour. Two of them if you really need
that 320 gallons.

This one is larger but has a lower first hour ratinghttp://www.ho****er.com/lit/spec/res_gas/AOSRG45700.pdf

Before you make a final decision, look over the offerings available and you
may find you can get more output from a good single unithttp://www.ho****er.com/lit/spec/r-gas.html

Note that on the web page (left side) there is a link to dsireusa..org Check
it out as there may be some rebates or state money to help you buy a more
efficient unit.

It's Newt, the origninal poster ----

My heat is gas, forced hot air; completely separate from hot water
system.

OK - You've sold me on abandoning dual HWH solution.
Will go with single HWH unit.

It would still be easiest for me to use the chimney for venting.
I also favor non-power venting to the chimney so I am not dependent on
electricity for hot water.
Back in 1991, I was without power for 11 days (ice storm) and only the
availability of hot water made living in the cold house tolerable.

If I wanted to stick with this method, could your recommend a specific
AO Smith unit for me?

Most intensive hot water use for us is to fill a Jacuzzi (seldom).
Most common high demand use is fifteen minute showers.

If I have to, I will vent to outside. Current location of HWH is in
middle of house, so I need to route exhaust pipe to suitable exterior
wall.

I thank you all for you help on this.

Newt.- Hide quoted text -

- Show quoted text -

How many BTUs is existing tank? High Output ones are 75,000 BTU,
common tanks 34,000 BTUs.

I have a high output 50 gallon, which is no longer made.

Home Depot and lowes both sell by special order 75 gallon 75,000 BTU
tanks.

Get some friends to help get it in basement and old one out- Hide quoted text -

- Show quoted text -

You do mean your 50 HO model is no longer made, I hope. 40 and 50 gal
HO tanks are common if you look, talk HO I have an 90 gallon with
about 180,000 btu input. HD wont have quality, efficency or the real HO- Hide quoted text -

- Show quoted text -

I checked several sources including the last real plumbing supply
place around here all report 50 gallon 75,000 BTU tanks are no longer
made. Want the higher output? Go with 75 gallons.

Its a fit issue for me and why I havent replaced the tank on my normal
schedule.

Other things must be moved to make room- Hide quoted text -

- Show quoted text -

Hallerb your full of crap again, I googled one model to not waste
time, the Vertex by AO Smith puts in 76000 btu in a 50 gallon tank. If
I spent 5 more minutes I bet I would find more. Your sources, searches
and info are bad.

On Jan 4, 9:17*am, " wrote:
On Jan 4, 5:22 am, ransley wrote:





On Jan 3, 10:16 pm, Pat wrote:

On Jan 3, 1:06 pm, Newton wrote:

I'm looking at replacing my 17-year-old 75-gal Hot Water Heater with
two 50 gallon units.

The current one vents into the chimney by way of galvanized ductwork.

What is the recommended way to vent the dual heater setup?
I am concerned that if one heater goes off, exhaust gas from the other
one might find its way back into the house by traveling backwards thru
the ductwork of the heater that is off.

Thank you.

Newt


For the cost of doing that, you could get a nice tankless hot water
heater. Then there would be no capacity issue and you could easily
get it down the stairs.

I have a Ng tankless and wont put in a tank again, but here its like
convincing folk their V8 car gets crap milage, they give you 100
reasons they want another V8.- Hide quoted text -

- Show quoted text -

nope there are good reasons to avoid tankless, no hot water at all
during power failures, excess up front cost, new gas lines and
possibly new meter because a large tankless has such high BTU, no hot
water at all with low flow like valve just opened a little, delay from
water on till hot water is available, tankless must detect water use
then yurn on burner. tankless payback period will likely exceed life
of unit, plus unit needs regular service from trained technician.

regular tanks tend to be install and forget till they leak- Hide quoted text -

- Show quoted text -

Your biased and full of crap again. I have HW with no power on a
Bosch 117000 btu, I have battery ignition.
600$, well I got a 4.5 year 100% return, show me any investment as
good.

My new gas line was about 8 ft or so, big fkn deal.

So dont open it a little, get used to it. A V8 doesnt accelerate
like a 4, do you still buy V8 cars.

Delay is maybe 30 seconds more but the burner lights in 3-5, I have
like most all a delay any way. Is your life that rushed 30 seconds is
such a big deal to save alot of money on utilities, CFLs have a delay
till they are bright.

What regular service you cant do your self, that is total crap what
you say.

A new meter. doughtfull, meters have excess capacity

Tankless, dont loose efficency from bottom scale every year as tanks
do,Tankless are the highest effecency waters heaters made with only a
few condesing tanks that can even come close to 82 EF, Tankless Takagi
is 94EF. Tankless coils last by design 30 years. For a few
inconviences you get a produst that can save you alot and last longer.
The lowest efficency tankless Ng is 82, avg tank is 55-65 EF, Tankless
go from 82-94EF Tanks go from 55-82 EF. EF is the only true rating
that is to be used comparing water heaters.

Lets not forget you never had one. I have one and I have tanks