Indoor Vs Outdoor Tankless Water Heaters

limitdiy · 01-10-2010, 10:24 AM

Does it make a difference if your tankless (natural gas) water heater is inside or outside?

I see both available at Home Depot. Would an indoor one heat the water up faster?

My current water heater tank is indoors upstairs.

http://www.homedepot.com/webapp/wcs/...reCity=Webster

Bob Mariani · 01-10-2010, 10:46 AM

Indoor will work better since it is not working against the cold outside air. How would the pipes to connect this unit not freeze if it is outside.

vsheetz · 01-10-2010, 11:16 AM

I would think the outdoor units are meant to replace existing tank water heaters that are presently located outside. Desert areas such as Las Vegas have water heaters located outside.

The washer/dryer may also be located outside...

Thurman · 01-10-2010, 11:18 AM

Bob, and others, please remember that there could be local codes involved with this issue also. Here for instance, IF you have a natural gas, tankless water heater installed it must be installed outside of the living area of the home. And--the local City's Water/Gas/Light Department is the only way to obtain natural gas, even in some areas of the county. Now, if you would want one which operates using LP gas, these are not permissible within the City Limits ( they supply the Natural Gas remember), and the same rules apply as to where it is mounted by County Ordinance. What about an electrically heated unit? Hmm, as long as the rated current draw does not exceed 30% of your main breaker within the panel, you may have an electric unit. And--YES, you have to obtain a permit to install any of the above mentioned units, City or County, AND-you must be a State Licensed Electrician to wire one, or a State Licensed Gas Fitter to plumb one up. Want to know why the apron stores here don't sell them, or why they are not so popular around here? Thanks, David

limitdiy · 01-10-2010, 12:27 PM

Quote:

Originally Posted by Thurman

Bob, and others, please remember that there could be local codes involved with this issue also. Here for instance, IF you have a natural gas, tankless water heater installed it must be installed outside of the living area of the home. And--the local City's Water/Gas/Light Department is the only way to obtain natural gas, even in some areas of the county. Now, if you would want one which operates using LP gas, these are not permissible within the City Limits ( they supply the Natural Gas remember), and the same rules apply as to where it is mounted by County Ordinance. What about an electrically heated unit? Hmm, as long as the rated current draw does not exceed 30% of your main breaker within the panel, you may have an electric unit. And--YES, you have to obtain a permit to install any of the above mentioned units, City or County, AND-you must be a State Licensed Electrician to wire one, or a State Licensed Gas Fitter to plumb one up. Want to know why the apron stores here don't sell them, or why they are not so popular around here? Thanks, David

Gotta love the state, just reminding us all who's boss.

What is LP gas?

nevermind...liquid propane, right?

jbfan · 01-10-2010, 07:03 PM

One of the reasons to mount outside and not inside is the venting.
If mounted outside, the vent just vents, and inside you must use the special vent pipe, which is costley.
Since an electric unit does not need venting, it makes no differance where it is mounted.

limitdiy · 01-12-2010, 11:47 PM

Quote:

Originally Posted by jbfan

One of the reasons to mount outside and not inside is the venting.
If mounted outside, the vent just vents, and inside you must use the special vent pipe, which is costley.
Since an electric unit does not need venting, it makes no differance where it is mounted.

if i have a tank water heater that runs off of gas that is inside right now...do you think the venting is already in place?

pyper · 01-13-2010, 07:41 AM

Quote:

Originally Posted by limitdiy

if i have a tank water heater that runs off of gas that is inside right now...do you think the venting is already in place?

There could be more than one answer, depending on which tankless heater you have.

The one I have required a 5" double wall pipe. The existing tank heater had a 4" single wall pipe. So I had to put new venting in. The tankless also has a minimum rise requirement, that complicated matters, and it needed 5/8" LP supply lines, meaning a new regulator.

The one saving grace is that it shouldn't ever wear out.

vsheetz · 01-13-2010, 12:31 PM

Quote:

Originally Posted by pyper

There could be more than one answer, depending on which tankless heater you have.

The one I have required a 5" double wall pipe. The existing tank heater had a 4" single wall pipe. So I had to put new venting in. The tankless also has a minimum rise requirement, that complicated matters, and it needed 5/8" LP supply lines, meaning a new regulator.

The one saving grace is that it shouldn't ever wear out.

I had the same pipe change to make - which nessitated an enlargement of the roof opening and reflashing. Was not a big deal to do.