water heater failed .. need a new one ... tankless?

[rodi]

We switched to tankless in 2006. Our old tank system and the hot water lines had a ridiculous run from the garage to the bathrooms and kitchen. Uninsulated, through concrete slabs (which cooled the water) then up to the attic, drop down to the upstairs bathrooms, then down to the powder room downstairs, then over to the kitchen. It took a VERY long time to get hot water at the kitchen sink. Tankless was mounted on the side of the house near the kitchen window - to the kitchen sink - over to the bathrooms... No slab, no attic, short runs with new insulated pipe runs.

We have never looked back.

Ours is a Noritz brand. We had to flush vinegar through it last year because our water is super hard... but other than that - no maintenance or issues.

 

[tb001]

I really question the "lower gas costs". Water heaters just don't use much gas to keep the tank warm. It's the initial heating from ground water level that takes the energy, and that's common to both.

Perhaps your old water heaters had a build up of minerals and became inefficient? In that case, replacing them with a new tank-style could have seen lower gas costs as well. Not so much a function of tank vs tank-less.




-ERD50

Our tankless replaced two 75gal water heaters that were 10-15 yrs old. We definitely saw a change in our gas bill. It may be, as you suggest, a mineralization issue, but I have to think just replacing the double system was part of it.

 

[albireo13]

tb001 ....
Where do you live?
We live in NH where the ground temps can get very low in the winter. I am concerned that a tankless heater would struggle keeping up. That would be a deal-breaker for me.

 

[RetiredHappy]

We have a tankless hot water heater with a recirculating pump. Initially it was set to 125 degrees but I like water to be hotter and changed it to 130 degrees. We really like it and it provides as much hot water as we need, including filling a bath tub. With the recirculating pump, water gets hot quickly.

 

[zinger1457]

The kitchen however, is a long run across the basement for the plumbing. The kitchen sink always takes forever to get hot water. I am considering installing a point-of-use water heater just for the kitchen sink/dishwasher.

If you want to get hot water quicker to a distant location you can install a recirculation pump. I have the Watts pump installed, cost about $200, fairly easy install or have the plumber do it when installing the new water heater. You'll have hot water almost instantaneously at your kitchen sink and save a lot of water.
https://www.amazon.com/Watts-500800...1&sr=1-1-5985efba-8948-4f09-9122-d605505c9d1e

 

[albireo13]

I measured our kitchen sink flow ... wide open is 1.5GPM.

The cold water temp today from the faucet is 43degF. The temp of water inflow to the basement heater would be lower ... maybe 38deg-40degF is a guess.

 

[GenXguy]

Funny you ask, as just replaced our system yesterday due to age plus our new home insurance wouldn't accept a 16 year old system despite no issues.

Interesting. My insurance company has never asked about the age of the water heater, roof, or anything. But I guess this is a good reason not to change insurance companies.

 

[Aerides]

But I guess this is a good reason not to change insurance companies.

In florida that is not an option. Many of us have to change every year, from either getting dropped, providers leaving, or rate hikes that defy reason.

We are actually getting a home inspection today as we're switching to avoid a 30% increase.

 

[Out-to-Lunch]

Here is the thread that tb001 mentioned: https://www.early-retirement.org/forums/f27/tankless-water-heater-and-recirculation-pump-110294.html

 

[Out-to-Lunch]

One way to look at this is break even point. Let’s make up some numbers. Let’s say replacing the current WH is $1500. Let’s say a tankless is $4500.

$4500? Where did you pull that number from? I put a top-end one in for ~$1200. Admittedly, I did the installation myself, but tankless heaters are not as expensive as you imagine.

 

[Sunset]

We replaced our 40G water heater with another exactly the same size.

Wish I had thought about it for a minute or two longer, as I should have gotten the 50G size.

Lifespan of a tankless water heater, from what I read is ~20 yrs so almost twice as long as a tank water heater.

 

[Dash man]

We have Navien tankless gas hot water heaters in four properties and love them. One property is a Jersey Shore rental, so at times the house has 12 people occupying it. Nobody has to wait for hot water. We’ve never had a problem with any of them in five years. They do cost more initially, but our gas bills have dropped. However, they do need maintenance yearly, so that adds to the cost.
The water is plenty hot and takes about the same amount of time to arrive to the sink or shower/bath.

 

[finnski1]

We replaced our 40G water heater with another exactly the same size.

Wish I had thought about it for a minute or two longer, as I should have gotten the 50G size.

Lifespan of a tankless water heater, from what I read is ~20 yrs so almost twice as long as a tank water heater.

My tank water heater is into it's 19th year and working fine. It is PEX lined and has no anode rod which may explain it's longevity. I thought it was dead a few months ago but I was able to epoxy the little temp sensor back in the top and all is well. The actual tank has been fine

 

[Jerry1]

One way to look at this is break even point. Let’s make up some numbers. Let’s say replacing the current WH is $1500. Let’s say a tankless is $4500.

$4500? Where did you pull that number from? I put a top-end one in for ~$1200. Admittedly, I did the installation myself, but tankless heaters are not as expensive as you imagine.

I think I clearly stated above that the numbers were made up. Though, I did think of it in terms of having the work done versus DIY. Either way, the number came from being three times the $1500 so I wouldn’t have to do any difficult math.

 

[tb001]

tb001 ....
Where do you live?
We live in NH where the ground temps can get very low in the winter. I am concerned that a tankless heater would struggle keeping up. That would be a deal-breaker for me.

We live in SoCA, so don’t have truly frigid weather. That said, ours is located in an outdoor closet and we hit 28-30 degrees a few weeks ago. I wondered if we would have a folder shower that morning, but seemed to be no difference.

 

[Out-to-Lunch]

I think I clearly stated above that the numbers were made up. Though, I did think of it in terms of having the work done versus DIY. Either way, the number came from being three times the $1500 so I wouldn’t have to do any difficult math.

Okay, fine. I see that you were giving instructions on how to think about it, not actually purporting to do the calculation.

However, later in your post, you come to a conclusion about whether tankless or tanked is better in your situation, without having actually done the math with real figures.

 

[Jerry1]

Okay, fine. I see that you were giving instructions on how to think about it, not actually purporting to do the calculation.

However, later in your post, you come to a conclusion about whether tankless or tanked is better in your situation, without having actually done the math with real figures.

Well, I left out things that I'm aware of that make me pretty sure the tankless install would be a nightmare. I had just put in a pool heater and I know my meter is already at capacity. I also know that the ventilation will be problematic. Otherwise, I'd consider a higher efficiency unit. My current tank vents up the chimney. Given all that I did conclude that a tankless wasn't an option as I suspect that the install cost will be significant and I don't think my time in the house will be long enough to get to breakeven.

All that being said, when I get the job quoted, I will confirm my thoughts.

 

[zinger1457]

$4500? Where did you pull that number from? I put a top-end one in for ~$1200. Admittedly, I did the installation myself, but tankless heaters are not as expensive as you imagine.

Actually $4500 was close to the estimate I got for installing a tankless, there was some additional work needed, installing a larger gas supply line and installing a new vent system.

 

[pb4uski]

$4500? Where did you pull that number from? I put a top-end one in for ~$1200. Admittedly, I did the installation myself, but tankless heaters are not as expensive as you imagine.

+1 As I recall, ours was $1,750... since it was a new build installation was bundled in with a lot of other plumbing work.

 

[pb4uski]

tb001 ....
Where do you live?
We live in NH where the ground temps can get very low in the winter. I am concerned that a tankless heater would struggle keeping up. That would be a deal-breaker for me.

Our tankless water heater is in our Vermont home... and a colder, higher elevation part of Vermont at that... our own small sub-arctic zone as I am fond of calling it.

We lived there full-time for 5 years before we started snowbirding and never had a problem of not enough hot water... it kept up fine.

 

[albireo13]

pb4uski,
Can you tell me what model tankless you used?
Thx

 

[pb4uski]

The brand was Takagi. Not sure of the model but I think it was TK-3 or something like that. I think their models are totally different now.. ours was installed in early 2011 and is still going strong.

About 5 years in we had to replace the heat exchanger, for about $500 as I recall. I think it ws taking a beating because we were using it for both heating and domestic hot water. Since we've started snowbirding the building is at 55F rather than 68F so it doesn't run as much.

Given it is 11 years old I suspect that we are running on borrowed time, but it is still going strong.

 

[MC Rider]

Plumber tried to sell us on a tankless when they repiped the house. But it would have been $600 just for bigger gas lines. And this was 12 years ago. We said give us a tank type.

 

[GalaxyBoy]

I had a tankless water heater installed in a previous house that had propane. Luckily I had previously replaced the old propane furnace with a heat pump so there was more than enough capacity in the fuel line. There were some plumbing costs as th3 old tank heater was vented through the roof but the tankless had to be on an exterior wall so the flue could go directly outside. In new construction I think a tankless would be a no brainer.

It could produce endless hot water so that wasn’t a problem. My only complaint was that it took time to deliver hot water to the master bath on the opposite end of the house.

 

[Out-to-Lunch]

tb001 ....
Where do you live?
We live in NH where the ground temps can get very low in the winter. I am concerned that a tankless heater would struggle keeping up. That would be a deal-breaker for me.

My water supply is the bottom of Lake Michigan. Hence, it is close to 39F all year round.

(39F is the temperature where water is the most dense, so it sinks to the bottom.)