Tankless Water Heaters (electric, hot water, clothes)

[Johnny C]

The water in your hot water pipes will cool to ambient temperature during periods of non-use regardless of the type of water heater that you use. If the ambient temp around any of your pipes can dip below freezing, then you may see some ice in your pipes.

If you had no problems with pipe freezing using a tank heater, then I wouldn't expect any problems with a tankless heater.

[Hopes]

I do have a problem in one bathroom. *sign* Apparently the actual tankless water heater itself can freeze if it's not vented properly indoors. Then there are models that are installed outdoors so those pipes are at risk of freezing too in our climate.

I'm beginning to wonder if it's truly worth the cost. A gas installation will be very expensive. In addition to the water line needing to be changed, the gas line will also need changed in addition to ventalization work. An electric unit is cheaper to install, but it's only 8% more efficient than an electric water tank. We have a gas water tank so that means an electric tankless will cost more to run than our current system.

I'm still tempted to install a gas tankless. Unfortunately, it's the gas tankless water heaters that seem to have the freezing problem since they are often installed outside for venting issues. That's why I'm wondering if any Pittsburghers have the tankless water heaters. They're apparently not as good for colder climates.

[JoeLeaphorn]

Originally Posted by Hopes

Not if you install point of service water heaters.


He didn't have a larger water line installed for his Jacuzzi.

Sure, and if you have tons of money, installing point of service water heaters may make some sense. But they you have to look at other costs, like added plumbing costs, where to locate the devices, retrofitting already constructed homes, etc. And, with current technology, electric tankless POS heaters are unable to handle large volume needs so you have to run gas to each location. That is barely practical for new construction but cost prohibitive for most retrofits.

Plus, the same issues that concerned you at first (though why you bothered to ask for others' opinions since you seem to disagree with everyone), which is if your concern is the temperatures in Pittsburgh then you multiply that concern with multiple POSs. The tankless vendors assume a starting water temperature of around 50 degrees. Pittsburgh gets its water from the rivers which tend to cool off in the winter (often below 50 degrees).

And the issue with my brother-in-law who had well water and lived in New Jersey, was not the size of the water line but the ratio of temperature rise to flow rate of the water heater (increasing the flow rate would simply make the water cooler). The plumbers recommendation was to add a second tankless water heater in series.

We all know that you wouldn't do this, however, because warm water heats more slowly than cold water.

[JoeLeaphorn]

Be careful what you read about outdoor tankless water heaters. While they may offer "freeze protection" down to -30 degrees F, that doesn't mean that they'll effectively heat your water at those temperatures.

Also, remember that with the indoor, direct vent, heaters, in most cases you have to have electricity to operate the fan (and possibly the ignition, unless you want to use a pilot light system). No electricty means no hot water. Considering that in the past 6 months, we have had two major power outages lasting 4 days, in one case, and 2 days in another, that would have meant no hot water, no dish or clothes washing, etc. Of course, you could by a standby generator...

[aveojohn]

Heres a link with plenty of info---http://www.tanklesswaterheaterguide.com/

[Goodjules]

I saw a combo traditional/tankless water heater on one of the home improvement shows recently. they claimed it offered the best of both types. anyone know about these?

[Plumber26]

Originally Posted by Hopes

It still freezes faster regardless of the process. And I did find some information about certain tankless versions that are prone to freezing.

My main concern is using a tankless water heater in the Pittsburgh climate. I've been reading about a reduction of output when the input water is colder in the winter.

I'd hate to install one this month only to find that it doesn't serve us well in the winter.


The cost isn't much of an issue. Tank water heaters are becoming expensive so the initial cost difference isn't as great. Plus tankless water heaters last longer, cost less to operate, and qualify for federal tax credit of $300.

I think unlimited hot water offsets the time delay. Point of use water heaters eliminate the wait time. I might install more than one system to address that issue. Still it's a huge change. I don't want to spend money installing it only to hate it.

I also want to talk to my heating/cooling contractor. I remember our boiler has a feature for heating tap water, but I think it still stores in a tank.

I'm sick of water tanks and water in the basement when they need to be replaced. They don't last long, but tankless water heaters last 20 years.

Actually the tax creditis 30% of the total installation cost up to $1500.
I have never experienced any of these "quirks that you guys speak of. Also if you go back with a tanktype water heater "State" makes a stainlees steel tank that is supposed to last 20 years and I believe that it is 98% efficient. There is always more than one option with tanktype heaters and they are improving every year. And like with most things, if they are installed properly and maintained regularly, they will last longer. Still, tankless is my favorite.

[Utah234]

Too bad you waited until your tank was leaking. One of the best ways to get the most for your money is to have an in-line tank that passively heats water going into the tankless unit - assuming that your old tank is in a heated part of the house. But if your space is a livable temperature you can still use the idea to save big bucks.

[bbw6400]

Owned a propane tankless for y years and it was the smartest, safest investment we ever made. NEVER one problem in those years. We lived in north GA so weather was not an issue even though it got very cold at times but not for days on end. We downsized to a mobile and are purchasing again. BB6400

[kirk1233]

A tankless heater came with my home that I purchased over four years ago and I think it is great. The water doesn't get as scalding hot in the winter but it is hot enough, and no freezing issues. The delay doesn't seem much longer than some places I have seen with traditional tanks either... I'm not heating water I'm not using and I can't run out!