I need to update my home hot water heater. I'd like a tankless instant hot water heater. Despite wanting to do my part for climate change, all indications point me towards getting as natural gas unit instead of electric.
Your mileage will almost certainly vary, but in my case the upgrade to a tankless water heater meant that the max gas draw for my house (if the water heater, furnace, stove and gas fireplace were all firing at once) would exceed the existing gas service to my house. So I had to get the gas company out to upgrade my service, which meant having the existing utility lines located multiple times (as the first markings washed away by the time the gas company came out), and I had bits of my yard dug up, etc. I also had to have county inspection folks come visit, and coordinate that with the plumber, etc.
The exhaust for my water heater is right next to the border with my neighbor's townhouse, and they've got a deck at right about that level. And it turns out when a tankless water heater kicks on, the gas comes on for a second and then it ignites, pushing a small amount of unburned gas out the exhaust. My neighbors occasionally catch a whiff of that, and I've had to have the installer visit and get on the phone with the water heater manufacturer (Rinnai) to reassure them that everything is safe and working correctly.
All told, if I knew then what I know now, I would have just gotten a new tank water heater - and I'm sure the entire process would have been over and done in a day, with no damage to the lawn or skittish neighbors. The guy who installed my water heater was a nice guy but I would have been happier meeting him once rather than a half dozen times.
But if you wouldn't have to have upgrade your gas service or aren't worried about the exhaust location - by all means, join me in having infinite hot water!
My only complaint with my new (2013) tank gas hot water, is that the tank already cracked and had to be replaced. It was not cheap: $2200. This is a rip-off, but contractors are expensive. I think the new tank-less systems are supposed to be more reliable than traditional tank heaters.
We just did the same on our 2014 house, which had a builder supplied 50gallon natural gas water heater. Those continually burn natural gas in varying amounts to keep the tank's water heated.
In contrast, the tankless natural gas is a massive win just wrt natural gas, as it's only running when hot water flow is required.
Not really - they're very well insulated, so they do a burn/coast/burn cycle where they are off far more than they are on.
That said - I'm a big fan of tankless, however in a big family with typical loads, the savings in gas alone aren't as much as you'd think.
Here's Matt Risinger's take:
There are big yellow efficiency tags on the front of every appliance for sale in USA. The content of those tags is closely regulated by the government. If there is some reason to believe that they are inaccurate for tankless water heaters, please link to that.
Given the gulf in efficiency between tankless gas and heat pump water heaters, tankless gas shouldn't really be promoted as examples of high efficiency.
https://www.energystar.gov/productfinder/product/certified-w...
* uses less energy
* never run out of hot water
* units are longer lasting
This is what I did, been very happy. Total cost wasn't more than $1,600 (DIY). Tankless is a nice idea but was just too complicated to ever pay for itself as a retrofit.
Electric Tanked WH: $600
DWHR: $800
Parts, pipe, new electrical circuit, new breaker, etc: $200Tankless are smaller and it’s true they won’t run out of hot water so they do have that going for them.