Natural gas Tankless water heaters, inside versus outside... vs Snowpocolypse...

[horn4life 3,748]

I am seriously thinking of spending the cash and replacing a relatively new Water heater (6 years old) with a natural gas tankless unit.  First off I have a CHOICE of whether to put the unit indoors or outdoors.  But aesthetically the finished look would likely be nicer if I buy an indoor unit.  The best installation point to take advantage of existing gas and water lines would allow for indoor or outdoor installation.  How would you/ did you protect an outside unit from freezes like we saw last year?  Or is it even possible with the necessary venting? 

Currently I have a closet in the hallway that houses both the hater heater and the air handler for the air conditioning.  I probably normally would not even consider this, but I am 95% sure I am going to bite off the cost to move the sir conditioner into the attic.  Around $4250 is my bottom line here, but it's motivated from the shitty design of my house and placement of existing AC that did not allow me to replace the ductwork with the current placement.  But with the air handling unit out of the closet, the appeal of the removal of the large water heater is now I would have a large closet area where I could move the washer and dryer from the garage into the house.  But adding another $1000 - $2000 with a tankless heater for the additional space is only really justified if I can use the closet for new washer placement. Though tearing out the wall and insulating the water pipes, is also something I think about as these lines did freeze in the snowpocolypse as they are in a currently uninsulated wall.

So how big a unit do I need?  I see ready availability of the $1000, 6.6 gpm heaters, and the $1400-$1700 units with 9.5 gpm units.  It's really just the wife and me now, so the most we might ever have running would be a shower and dishwasher or washing maching going at the same time.  With the possibility of an additional faucet running.  Do you think I can get by with the 6.6 gpm unit or would I need the additional capacity?  My plan is to time how long it takes to fill up a 5 gallon bucket in the tub today to see how much water comes out of a spigot.  I may try to fill two buckets in each shower to see what "max" capacity in a minute is?  I KNOW I have high pressure, 90 psi.  

I have not done enough research and don't have the time right now, so PLEASE Surly learn me on this stuff.  My guess is the flow will be such that I will want the 9.5 gallon more expensive units.  Simply as I will hate myself if I "ALMOST" got endless hot water.

ALSO - recirculating pump or just wait for the water to get there?

I did see the electric tankless post, but I would only go natural gas.  So thanks in advance.

 

[Mother mopar 3,262]

I have a tankless and it's mounted outside. We have it right above the gas meter about shoulder high on the same side of the house as the AC unit. While it does freeze I've never had a problem. Then again, the lowest it's been here (Fort Walton Beach, FL) is low 20s.

I enjoy the tankless. While it takes a bit to warm up, that's not a show stopper for me.

Regarding size, it's me Mrs. MM, and a teenage kid. The one we have (can't remember size) is perfect for us. Running dishwasher, shower, and laundry isn't a problem.

[Nivek 16,643]

Mine is in the attic. I do not have the recirculating system so the first person to shower in the morning can just let the pipe water drain while they strip is usually enough.

Mine tankless water heater is about 12 years old.

I live in Houston though. Recirculating might be more important up north.

[Quagmire 2,139]

That winter storm zapped my brothers so I would put it inside

[deadshank 24,644]

Gas fed tanked water heaters require no electricity to operate

Gas fed tankless water heaters require electricity to operate 

Puff on that while pondering the next snowpocalypse when the electrical power is out.   

Edited October 7, 2021 by deadshank

[Judge Roybeanbag 11,728]

1 hour ago, deadshank said:

Gas fed tanked water heaters require no electricity to operate

Gas fed tankless water heaters require electricity to operate 

Puff on that during while pondering the next snowpocalypse when the electrical power is out.   

Having a gas-fed tank heater, I would not switch to a tankless.  

[NeverMarryAStripper 21,765]

2 hours ago, deadshank said:

Gas fed tanked water heaters require no electricity to operate

Gas fed tankless water heaters require electricity to operate 

Puff on that while pondering the next snowpocalypse when the electrical power is out.   

However, they both require water to operate

[deadshank 24,644]

4 minutes ago, NeverMarryAStripper said:

However, they both require water to operate

What? You a lawyer?

I fondly recall taking hot showers during powerless hurricanes and even having enough water pressure to take a hot dribble back in February.   

[CooterBrown 17,695]

Gas fed tanked water heaters require no electricity to operate
Gas fed tankless water heaters require electricity to operate 
Puff on that while pondering the next snowpocalypse when the electrical power is out.   

Everyone I know in Austin that has an outside mounted tankless water heater had it completely frozen up so they had no hot water for days.

The tankless technology is cool but an old school gas water heater can’t be beat and it’s not that expensive to operate.

[horn4life 3,748]

My current 50? gallon water heater still looks new.  I think I wanted the space as much as anything for closet space or to move the washer/dryer indoors.  Dropping the $1600 plus probably is not as smart as simply flipping the water heater to the other side of the wall and spend a little more with the plumber.

Thanks for the replies and especially the comments about the need for electricity to run during power outages.  

[Jkwellborn 6,536]

I’ve got a tankless gas water heater. It’s mounted on the east side of my house. Never had an issue during the Snowpocalypse. It got below zero one day according to my phone.

[luke duke 6,359]

You may need an upsized gas line to support a large tankless water heater.

[milkman 428]

I am seriously thinking of spending the cash and replacing a relatively new Water heater (6 years old) with a natural gas tankless unit.  First off I have a CHOICE of whether to put the unit indoors or outdoors.  But aesthetically the finished look would likely be nicer if I buy an indoor unit.  The best installation point to take advantage of existing gas and water lines would allow for indoor or outdoor installation.  How would you/ did you protect an outside unit from freezes like we saw last year?  Or is it even possible with the necessary venting? 
Currently I have a closet in the hallway that houses both the hater heater and the air handler for the air conditioning.  I probably normally would not even consider this, but I am 95% sure I am going to bite off the cost to move the sir conditioner into the attic.  Around $4250 is my bottom line here, but it's motivated from the shitty design of my house and placement of existing AC that did not allow me to replace the ductwork with the current placement.  But with the air handling unit out of the closet, the appeal of the removal of the large water heater is now I would have a large closet area where I could move the washer and dryer from the garage into the house.  But adding another $1000 - $2000 with a tankless heater for the additional space is only really justified if I can use the closet for new washer placement. Though tearing out the wall and insulating the water pipes, is also something I think about as these lines did freeze in the snowpocolypse as they are in a currently uninsulated wall.
So how big a unit do I need?  I see ready availability of the $1000, 6.6 gpm heaters, and the $1400-$1700 units with 9.5 gpm units.  It's really just the wife and me now, so the most we might ever have running would be a shower and dishwasher or washing maching going at the same time.  With the possibility of an additional faucet running.  Do you think I can get by with the 6.6 gpm unit or would I need the additional capacity?  My plan is to time how long it takes to fill up a 5 gallon bucket in the tub today to see how much water comes out of a spigot.  I may try to fill two buckets in each shower to see what "max" capacity in a minute is?  I KNOW I have high pressure, 90 psi.  
I have not done enough research and don't have the time right now, so PLEASE Surly learn me on this stuff.  My guess is the flow will be such that I will want the 9.5 gallon more expensive units.  Simply as I will hate myself if I "ALMOST" got endless hot water.
ALSO - recirculating pump or just wait for the water to get there?
I did see the electric tankless post, but I would only go natural gas.  So thanks in advance.
 

Where do you live? The temp of your water coming into the house will make a huge difference on how well a tankless works.

[horn4life 3,748]

On 10/10/2021 at 8:19 AM, luke duke said:

You may need an upsized gas line to support a large tankless water heater.

I have a 3/4 inch line, so I think I am good there.  But THIS is exactly the sort of reason I post shit like this here.  It is something I might not have thought about until late in the decision making process.  

I live in Austin so the water temp is not warm, but not cold except when there is no power in the entire state...

[Jkwellborn 6,536]

Your plumber or even the website would tell you how many gpm to get.

[Jiggy-Z 3,419]

Circulation feature is nice, but I'm not sure it is worth hassle of the extra piping you will need to do it correctly.  We have a circulating model, but had to use existing pipes since we have a lot of concrete walls and 2nd floor deck is concrete as well.  When on circulation it was never as good as what we thought it would be.

We go through the same amount of propane with 4 people on the tankless as we used to go through with 2 people on the tank heater, so they are pretty dammed efficient, and with two teenage boys taking long soapy showers, we never run out of hot water. 

That being said, one could always up the wrap insulation on the tank and get that thing pretty close without all of the tankless issues and costs, even if you get a larger tank to ensure a large supply.

You will also need to to do the the scale cleaning every couple of years on the tankless to prolong the life of the unit. i did not do that on my first tankless unit and it gave out after 15 years.

There are subs that do nothing but install tankless, they can tell you what you need.  

Our tankless is inside and I always wanted it to be outside, until last winter.

[CooterBrown 17,695]

I have a 3/4 inch line, so I think I am good there.  But THIS is exactly the sort of reason I post shit like this here.  It is something I might not have thought about until late in the decision making process.  
I live in Austin so the water temp is not warm, but not cold except when there is no power in the entire state...

3/4” is the standard gas line size. The pressure coming from the meter on is probably 1/4 pound. It’ll need to be increased.

[HRSchenker 2,215]

My tankless water heater is in the garage and held up well during the storm. But I also had power the entire time. 

[Updawg 2,239]

Anyone have Recommendations for a replacement tank in Austin.

[Jiggy-Z 3,419]

1 hour ago, Updawg said:

Anyone have Recommendations for a replacement tank in Austin.

We looked at Mr Tankless and they came recommended.  Fair price, but we had too good of deal with purchasing on our own and using my business partner's nephew who is a licensed master plumber.  

[William_Cannon 86]

Mine is in the attic and didn’t have any issue during the snowpoco. However I drained mine to prevent issues.

[CooterBrown 17,695]

Anyone have Recommendations for a replacement tank in Austin.

If you’re a TGS customer, you get a $650 rebate for buying a gas tankless water heater.

https://www.texasgasservice.com/save-money/rebates-and-incentives/ctx-rebates-and-incentives/ctx-residential-rebates

[hrmaddie 48]

We've got a tankless, what a pain in the rear to get it installed too.  We didn't go cheapest install nor most expensive, went with a company we thought would do the job right.  Lots of problems created by going tankless, all stemming from the install.  Best advice is look on the manufacturers website for certified installers and ask for quotes.  Ours is in the attic and nearly froze during the snow shit storm.  We kept a space heater on it, when we had power, otherwise the plumber said it would have failed.  He said a neighborhood down the street where the builder put them all on the outside, they all froze and needed to be replaced. 

Your gas line will have to be upgraded, no way around that. 

Everything is working correctly now, but for a couple of months it was a pain in the ass.  Looking back at it now, I am not sure what the dig deal is with tankless, we never ran out of hot water..  We have a recirculating system, quick hot water was never an issue.  

Hire a reputable plumber, someone that is going to do the job right.

[William_Cannon 86]

Anyone have Recommendations for a replacement tank in Austin.

Mr Tankless (Bob Lemons) out of Cedar Park. Great guy. Wa s recommended by a friend.

[crash_davis 23,038]

late to this thread. in austin proper. my outside tankless and everyone who had outside tankless and loss electricity shit the bed during the ice storm. the tankless systems have internal heaters which prevent them from freezing but yea, that doesn't do any good when you lose electricity and the temp drops to low 20s.

what the $3900 tankless replacement taught me....

if you are going to lose electricity and it's going to freeze, you need to cut off the water to the tankless. easily done from the main water valve switch at the base of the system. then drain the hot water faucets in the house. this removes all hot water from the tankless and the pipes so the freeze isn't going to fuck your tankless system.

going without hot water is not bad. just boil water on the stove. going without any period for more than a day is a fucking nightmare, especially if you have to melt know to do anything, like take a shit. fuck our lege and Texas leadership for ignoring all the warnings and not doing shit to prevent it last time nor prevent it in the future. 

ideally, tankless water heaters should be installed in the garage where they have a much better chance of not ever freezing. next house i'm building, that's where i'm getting mine installed. 

firmly team tankless, but in the garage.

[crash_davis 23,038]

another thing hardly anyone mentions about tankless is the maintenance. ideally you need to flush the tankless heater every year to remove the calcium, mineral buildup from hard water. this is $150-200 per visit, depending on the plumber. however, it's a very easy DIY job. 

just need a 5 gallon bucket, a lot of vinegar, sump pump and two shorter garden hoses. takes about 1-1.5 hours. i've done it twice and very easy to do. set it up, turn on the process, go do other shit for an hour periodically checking to make sure something didn't go wrong. after an hour, disconnect everything and you're done.

[Jkwellborn 6,536]

You should be draining a regular water heater for the same reasons though.

[bigcigar 1,154]

On 10/29/2021 at 1:55 PM, Jkwellborn said:

You should be draining a regular water heater for the same reasons though.

Timely. Water heater just sprang a leak even though it’s only 4 years old. We got the house last year and ignored the drain pan warning from the inspector. Oops.

[deadshank 24,644]

On 10/29/2021 at 12:53 PM, crash_davis said:

another thing hardly anyone mentions about tankless is the maintenance. ideally you need to flush the tankless heater every year to remove the calcium, mineral buildup from hard water. this is $150-200 per visit, depending on the plumber. however, it's a very easy DIY job. 

just need a 5 gallon bucket, a lot of vinegar, sump pump and two shorter garden hoses. takes about 1-1.5 hours. i've done it twice and very easy to do. set it up, turn on the process, go do other shit for an hour periodically checking to make sure something didn't go wrong. after an hour, disconnect everything and you're done.

Treat your water with a filtration/ softener system when it enters your house’s supply line and before it gets into the interior supply pipe system and plumbed appliances.  
 

Worlds of difference.  
 

Of course, we could go on and on to retrofit our way to a perfect house.  What a few hundred $K?   But I hear  you.  Calcium carbonate and iron in water tears up plumbed appliances. 

[bernorange 8,336]

* bump *

We had a nat gas tankless installed roughly 5 years ago in the attic (Houston area).  It's worked great so far.  Really got us through the years where my oldest son took 1 hour showers 2-3 times a day (morning and then [pre and] post gym workouts).  We also have a whole house water filtration system on the main water inlet.

I did a big goof and never did any maintenance on the unit.  The filtration cartridge had to be replaced recently and we had the system flushed as well.  I'll be doing an annual flush/maintenance from now on.

Our system developed a strange and loud knocking noise.  Plumbing company misdiagnosed the problem as a inlet pressure valve which they replaced.  That didn't solve the problem so they came back and spent some time doing a proper diagnosis.  Turns out the heat exchanger inside is the issue.  Heat exchanger is still under warranty (15 years), but labor to replace it isn't.  Plumbing company gave me an outrageous quote for the replacement claiming it would take 8 hours.  Manufacturer says it should take about 3 hours.  I've already got competitive quotes from 2 other plumbers to do the job, but the manufacturer already shipped the warranty replacement part(s) to the first plumber.  What a headache this is turning out to be.