Should I get a tankless water heater?

Question

What are the pros and cons of tank vs. tankless? I have a gas line in place.

Answer 1

A tank less water heater must heat the water quickly on demand so you have hot water when needed so it actually uses more energy to accomplish that however a water tank is heated 24/7 even though you are not using hot water it is still heating it so it will be there when you need it therefore it is using more energy in the long run. Unless you use a lot of hot water throughout the day the (demand) tank less heater is more energy efficient. There is really nothing special in the way a tank less water heater works as far as the technology of heating is concerned as the burner is just slightly larger than used in the water tank to heat the water faster during the time hot water is used.

Answer 2

The pros are that it will have a much reduced fuel cost since you are only paying for heating when you use it instead of when you're not using it. Also, you will have continuous hot water, instead of a certain number of gallons.

As for cons, you mention that you have a gas line in place, but what about a gas vent? If you are replacing an electric hot water heater, you will also need to install a gas vent, which can be expensive. But if you have a gas vent in place already, that's not an issue.

A strange feature of the tankless hot water heaters is the higher the water pressure, the higher the temperature. If you have city water, then this probably won't mean anything to you, since your water pressure won't fluctuate. You will be able to choose a temperature from the hot water heater and live with it. But if you have a well and pressure tank, then your water pressure fluctuates probably between 27 and 50 psi. And as the water pressure goes down, so will the hot water temperature as you're taking a shower. One way around this is to install a pressure step-down valve after the water pressure tank to reduce the fluctuation to about 30-35 psi. Then you can set your water temperature and it will stay within a comfortable range, even as your pressure tank gets low and refills.

Answer 3

I looked really hard at installing one a couple of years ago. A friend has had a couple and he said they work fine if you don't have a lot of folks in the house using hot water. Apparently you can get spurts of cold water during periods of high demand. Not good during a shower. The only other drawback I could see is the initial expense, they are high priced little buggers. Home Depot carries them though. They had the best deal when I was shopping.
I ended up going with a conventional gas water heater. Much better than the electric one we had for years. I haven't run out of hot water since I switched over. I installed it my self, no big deal. I think the install on a tankless unit is pretty simple too. Check to see if the model you want requires a flu fan though. Some do.

Answer 4

I hear that they are more efficient and cost effective in the long run. The cons I have heard are that they are expensive to buy. Also since they are fairly new many models still have kinks to work out. Some of the less expensive models won't support multiple appliances at the same time so you'll have to spend some coin.