instant hot water heater

[jcouch1]

tankless hot water heater

I'm contemplating getting an exterior mounted tankless gas water heater to free up some space in my laundry room. Who gives you the best bang for the buck for a unit that will be able to supply hot water for a 2.5 bath house?

I've googled rheem and rinnai... are there others?

What's everyone's experience with these? Any particular models to get or avoid?

 

[nolimits76]

In my last house, I had the builder put a pump on my hot water heater that basically made it "instant hot" anywhere in the house. We did this to avoid adding a second water heater and wasting the space. Turned that into a closet for the 2nd bath.

I didn't do the install. But as I recall, the plumber had to run some extra lines to make it all work. In the end I was very happy. And cost was a wash vs the second water heater.

 

[jcouch1]

also does anyone know anything about Takagi tankless water heaters?

 

[Dale Leeds]

The tankless water heaters are awesome. They save money and give you instant heat. They are expensive, but if you can afford one, I'd go for it.

 

[Turbotboz]

I have a rinnai (sp?) tank-less unit. It works well BUT it can take a while to get the hot water from one side of the house to the other. Tank-less hot water heaters aren't necessarily "instant" hot water heaters. I'd consider them more of an unlimited hot water heater.

There are ways to plumb the house with the unit to make this a non-issue, but it requires recirculating the entire system ($$$).

 

[Dale Leeds]

I have a rinnai (sp?) tank-less unit. It works well BUT it can take a while to get the hot water from one side of the house to the other. Tank-less hot water heaters aren't necessarily "instant" hot water heaters. I'd consider them more of an unlimited hot water heater.

There are ways to plumb the house with the unit to make this a non-issue, but it requires recirculating the entire system ($$$).

Yep. You need to recycle the water and get it there faster when you have a long distance between the heater and the faucet.

 

[Zeke]

Long single story ranch style houses should have a tankless at each end or near a grouping of plumbed devices. My water heater sits near the main bathroom but takes a long time to reach the kitchen and even longer to reach the laundry. The solution is on unit outside the kitchen and one outside the laundry. The bathroom hot water draw will be gallons at a time. The kitchen and laundry, not so much. Waiting for hot water just to wash your hands and a couple of cups just wastes water.

 

[Charles (in GA)]

This very subject got beat up in March of this year in THIS THREAD, which you may find very helpful.

Charles

 

[Clik]

With a regular water heater you have some reserve if the power goes out. I can lose power overnight and still shower in the AM. Try that with tankless and you'll suffer severe shrinkage, especially on well water. Woo! Hoo!

 

[Scott H in Wheaton]

If you have a water heater why would you also need a hot water heater?

Who needs to heat hot water?

 

[Playwme]

With a regular water heater you have some reserve if the power goes out. I can lose power overnight and still shower in the AM. Try that with tankless and you'll suffer severe shrinkage, especially on well water. Woo! Hoo!

You can get ones that don't require mains power. We have a Bosch unit that ignites using a small turbine activated when the water rushes through. Others use a couple of D cell batteries for ignition. Power could go out for 2 weeks and if the gas is still on we'd have hot water the whole time. Try that with an electric storage unit.

 

[BBQ&Love]

Tankless water heaters are not instant water heaters. It's important you understand that or you will never be happy with them.

Here's a rule of thumb to begin understanding if they will work well for you. First ignore everyone who praises them without qualifications, and everyone who bashes them without qualifications. Their opinions are not to be trusted and they will lead you wrong.

Here's what you need to consider to make a wise choice.

1. Correct sizing must be done based on the following factors. Coldest incoming water temperature, water heater capabilities, and the correctly calculated demand. RUN from anyone who says any of these factors is not important.

2. Installation costs. This can sky rocket quickly. Just know up front what you are dealing with.

3. Maintenance costs. To keep the warranty valid and to keep them operating well, you have to do maintenance that is more involved than on a storage tank water heater.

4. Repair costs. Tankless almost always costs more than storage tank to repair.

5. Life cycle costs. Taking all costs into consideration, over a reasonable expected life cycle, what is the yearly cost of each type?

6. The installation itself. Tankless will not work well in some installations without adding a storage tank. Now you just have an expensive heating plant for your tank. You can usually use piping and circulators to overcome the same limitations.

If you are accurate with all these considerations, and the tankless still comes out ahead, then go for it! Stay away from lower end units like Bosch. Noritz and Rinnai are better choices.