We are installing tankless. We have it now and love it. Here's some info on the two:tankless vs indirect. The indirect looks interesting. I sent the info to DH to look over.

http://wayneheid.blogspot.com/2012/04/what-every-boiler-owner-should-know.html?m=1

I came across this, which sounds very promising. I do notice a great deal of pressure drop if two showers are running at once with my tankless.

cpartist that is a great link. Thanks.

Thanks. yours too. However us being in Fl I think makes it a moot point

I'm not sure I get tankless. My house has three water heaters, two 50 gallon plus a 20 dedicated to kitchen. I;m thinking that modern dishwashers having their own heater means the kitchen could work well with an on demand electric since it is only a sink that needs hot water. My current gas bill is $18.53 which is about typical when I don't have to run the furnace. Tankless needs electricity to run so in a power failure I would have no hot water? Also consumes electricity for the fan and electronics. Also has maintenance and whatever else I haven't thought of.

We have had tankless in the last two houses we built and will have nothing else! Endless hot water is the way to go! In the last house we even filled our hot tub with hot water when we did water changes, no waiting for it to heat up. Oversized jetted tubs, not a problem. 10 people taking a shower in a row, not a problem.

chris which ones do you install?

We have tankless now and agree with Chris.

And I have a secret for you gregbradley. With most regular water heaters nowadays, you also need electricity for them too, so if you lose electricity, your water will eventually run cold too.

We used Rinnai the last two times and are trying a Navien this time. I hope we like it as much as we did the Rinnai.

If any time to install a tankless would be during build. Trying to upgrade later is a pain and involves either increasing the gas line size or increasing the electrical main size.

Vith, we upgraded from a tank in our condo five years ago. Not sure if the electrical main was increased or not but it works fine.

Depends on what you had for service. You must have had enough. I can tell you, if you needed to upgrade your main electric, you would have known it (to the tune of about 3 grand). Recommended house service amps is 200 A for a whole house electric tankless and it takes 3 to 4 40A breakers in the panel.

Yes we had 200 A I believe or maybe we did upgrade and like when giving birth I have forgotten the bad parts.

I've had a tankless for 20 years. Zero problems. And I have hot water when the power goes out. If that is a frequent problem for you, then you should also be designing the home with a separate sub panel for critical electrical and an auto on generator to supply the critical electrical. Natural gas generator. It's cheap to do when you do it that way from scratch. Not so cheap to retrofit. Just like the tankless. Gotta have a big enough supply line for it all though. That's also best planned from the beginning.

We are in Earthquake country and have very cheap natural gas. We have chosen a tank for the emergency water it provides. We upgraded the size to 75 gallons so I could FOR SURE fill my deep soak tub.

When electric goes out, she doesnt NEED a battery backup or a generator to get hot water with a tank. That is probably why she chose a tank. Battery backups go out over time as well, they are batteries (which dont last forever). I personally just replaced three battery backups (for computer, TV, gaming) because they just didnt hold a charge anymore. One of those battery backups decided to just stop holding charge after a year too. Just another complication. Tanks are just less complicated and require less maintenance. Both have their place, I prefer tanks myself but understand others enjoy tankless. I actually was interested in tankless at one point, till I learned it wont run in a power outage and I would have to upgrade my main service amps (gas/venting probably wouldnt work where I wanted the heater).

Vith,

I did not have space for a 75gal tank in my home. A forty gallon tank does not last very long when there is a power outage in cold weather. Actually space was a major consideration with the decision to go to tankless. I have a house full of battery backup systems. My battery backups have needed batteries replaced every 5years. Mine are sine wave backups which I need for my server and other sensitive electronics. I live in an area with frequent power outages so I researched and investigated my options carefully. Most newer gas stoves are not usable in a power outage also. The beauty of this is that we all have choices and manufacturers make things so that we have those choices - tank for some, tankless for others.

Are you saying a gas tankless water heater would require you to upgrade your electrical? Or that you could not have a gas tankless water heater because of venting? Where does your current gas tank water heater vent to? We just the same location for my tankless.

Again, you made a choice that fits your lifestyle or the point in time you made the decision. It does not mean that Tankless water heaters are bad and inherently have all these flaws. I spent so much time researching these things and kept hearing about the cold water sandwich which was my biggest concern. I have experienced no such thing. I also had a unique situation where with the tank water heater, I could not get a re circulation system like the Metlund working without replumbing the house. The Rinnai tankless has a built in re-circulation system that runs for two hours in the morning and two hours at night (programmable timer based) and we have instantaneous hot water.

Good luck!

I am in processing of finished my new construction. No tankless for me.

This was good to read, in our new build we are getting the tankless and I was a little worried about how well it would work for us. There was really no good place to put a tank so our builder suggested tankless instead. He swears by it.

Homepro,

I was not discussing flaws. There are pros and cons to both tank and tankless, its up to the owner to make a choice. I have an electric tank water heater so I do not have to deal with combustion air in the house or the need to buy an expensive direct vent water heater and I can also place the water heater anywhere I want with an electric. Also, I dont want to rely on a battery backup for hot water during short power outages, and thats if it was a gas tankless, if it was electric then forget about it. Obviously if the power goes out for a long time I will lose hot water, but how often does that happen, not often.

You can attempt to make as many solutions as you want, but what it boils down to is that I want a simple system and thats it. Tankless has its advantages, but its cost and complexity do not interest me.

And I don't want to have to replace a tank every ten years. :)

Sandy, I wouldn't consider building new and doing a tank anymore. In the five years we've had our electric tankless in our condo, we've had no problems getting instant hot water for our showers and for our sinks.

Now I can't say the same for my place in NY where we have a 40 gallon electric hot water tank. I can stand there for minutes waiting for the hot water to flow.

And if DH decides to shower before me, I'd better wait at least 1/2 hour before I decide to shower. Otherwise, I wind up rinsing off in a cold shower. With the tankless, no such problems.

Vith,

Depends on where you live. My last power outage was for 7days!

Vith my sister was out for almost 3 weeks after Hurricane Sandy.

I always find these threads interesting. We replaced our tankless with a tank last year, because two people could never shower with hot water at the same time, or do laundry and shower, use the dishwasher and shower, wash hands with hot and shower, etc. We had the tankless for 13 years and finally switched to a tank. We can now do any combination of those things and everyone has enough hot water!

Interesting, in two houses, we had none of those issues...

Interesting experience pippiep, with a 40gallon tank two people ran out of water with 2gpm flow heads. The third member of the household had to wait twenty minutes to jump in the shower. Do you remember what brand of tankless you had? It may be a cautionary tale for others to look out for.

Good luck!

As I said, my experience was and has been more like homepro

I have Rennai and like I mentioned before if two people are taking a shower water flow is greatly reduced.

We have a 60 gallon tank for 4 (two adults, two under 10y) because we didn't want to run out. My husband says the tankless was in the Weil Mclain boiler. It was annoying always having to coordinate shower times, especially with guests. But I can't seem to find anyone else that had the same experience as us. It was a HUGE improvement moving to a tank!

Pippiep,

I don't think the Weil McLain came with tankless units. I am going to restate this, I see they can come with a tankless unit but a boiler tankless appears to be a different beast from the conventional tankless heaters that I am familiar with. They were boilers mainly. People more familiar with the brand can comment. Did you have radiant heat in your home?

abick,

Do you know the model of your Rinnai tankless? What temperature is to set to? Do you know what your temperature rise is? Temp rise is based on the incoming water temperature. Also, water is the flow rate of the showers? I guess that you may have an undersiz d unit for your needs.

homepro01 -- are you saying that we'd probably have a much better experience with a different/better tankless setup? I definitely see the drawback of a limited tank and we had to think hard about switching to it from the supposed optimal tankless... but in our case, it was a beneficial move. My husband is now saying that we might've had more of a plumbing limitation, where our shower would get most of the hot water, and the kids/guest bath had a drinking straw for a pipe, which resulted in less hot water there. Also, we have low water pressure (well water). So it could be all those things combined, not the fact that it was tankless.

The house we're moving to has a 40 gallon tank, so we will likely see problems running out of hot water, especially as my kids get older.

Rennai R75LS set to 120°

Abick,

What part of the country are you in? What type of shower heads do you have in your bathroom? The R75ls is rated at 7gpm with a 25 degree temperature rise. There could be a few things going on with the performance.

Pippiep,

There are clearly a few things involved in your previous installation. I would look at a tankless water heater to match the capacity of your new home. Rinnai and Noritz make large capacity tankless water heaters. Water pressure does affect how tankless water heaters function too.

Good luck!

There is some confusion here, I think.

Hot Water can be generated by Tankless Coils, Water Heaters (tanks), indirect water heaters (tanks) and Tankless Water Heaters.

I am in the northeast. We have regular shower heads no jets or anything like that.

We have the Rinnai 199,999 in our new build. Fantastic. We didn't get the recirculation thing and don't miss it. We can easily do 2 things simultaneously with hot water. I can have the hottest water right up to my neck. Ours is propane and it doesn't use that much. Total use in 3 monthsfor hot water, cooktop, bbq, and fp has been 50 gal.

I totally love it.

In cold climates, tankless isn't very efficient. Our winter water temp is about 36°F; it takes a huge tankless unit to heat water 80°.

AnnKH,

Your incoming water temp is 36F? I have an uninsulated crawl space where my plumbing comes through to the majority of the house and my incoming water temperature in the winter is never below 50F. I live in the Northeast and we get winters where the temp is consistently at 10 degrees with ice to boot. Rinnai and Noritz both originated in Japan where winters can be quite brutal too. I am not sure a tank or tankless in a 36F water temperature situation would be very efficient.

When I first started researching tankless, I was really worried about temperature rise which is why I kept a log of incoming water temp for one year in my home. I also converted one of my showers to Thermostatic valves. We have the temp turned to 110 at the heater. I originally set it to 130 and it was so hot, it was unusable:-) At 50F, I am looking at a 70F temp rise and according to the Rinnai chart, I can get 5.5gals per minute. This is enough for two showers that are not using any cold water to temper the incoming water feed to run unfettered. My shower heads are 2GPM and 2.5GPM units. My faucets are now 2GPM including the kitchen faucet. I have a Rinnai RUR98i.

Abick,

Do you know your showerhead flow rates? Have you had someone come out and look at the performance of the water heater? You should be getting roughly 4gpm at a 70 degree rise.

Good luck!

I think my showers are 2 or 2.5. I should have someone take a look, but it was like that from the beginning. We replaced the traditional tank with the thankless unit maybe that's why.

Abick,

It does not sound like it is operating correctly. You should have more than enough capacity. They may not have set up the venting correctly, etc. Do you ever see any error codes on the remote? I think my unit has a different remote from your and provides a little more information. Have a plumber check it out and verify the water temp at all the output points.

Good luck!