tankless water heater?

[touchofgrey]

I'm looking @ getting one of these. Nat gas fired, just wondering if anyone here has one and what the pros and cons are. I see on e-bay different ignition systems, bosch makes one with a small generator spun with water pressure. Neat if it works for a long time. Another one uses 2 D batteries, yeah I don't think I'll be buying that one. If it takes power, I don't think that will be a big problem for me. I also need a direct vent out the wall, as my chimney left years ago. Thanks in advance, D.

 

[Sako7STW]

I looked into them earlier this year. You would need to talk to a GOOD reputable source to figure out what size you need. The company I talked with figured it out by calculating how much would be needed if we were to run every sink and shower in the house at the same time. I dont remember now which one it was but I remember it was a middle of the road size for domestic applications. We have it on hold as the funds are not there yet.

We are also going to look at using it to heat the house by converting our forced air heater to push through a radiator that is heated by the tankless. Claim it will drop your gas bill by 2/3.

 

[Wolfrun]

I have no experience with the natural gas units but I have had an electric unit in my cabin for about 4 years and it works great. The gas units are much more in use than the electric ones so they ought to be real good. When I was looking at them, Home Depot had the gas units in stock but I had to order the electric one. I would do it again.

 

[jscanga]

I run a Rinnai tankless in my home--best thing since sliced bread (IMO). You can easily adjust the water temperature with the push of a button, delivers unlimited hot water fast and you never run out! I sprung for the extra to get the commercial version as you can get a little hotter water and it has a higher output. No problems showering, washing dishes, clothes etc at the same time.

 

[DrSmooth]

Rinnai is probably the way to go. Takagi also makes one but Rinnai is the market leader, I think. They work pretty well... nice to have an unlimited source of hot water for filling a bath tub, taking a long shower, or if there is more than one person taking a shower at a time. The only thing i don't like is that if you want to run a circulating pump so you don't have to wait a few minutes for the water to get there, the unit is constantly running. I f you don't mind the wait, they're great. Make sure if do get one, you check the factory temp setting. We had to raise the temp on it to the second highest setting so that we didn't just get luke warm water coming out of the shower... especially if the shower has an anti-scald valve on it. Bottom line, I don't mind the wait so I think it's worth it.

 

[touchofgrey]

Thanks for the replies guys. Smooth @ canga, did you guys notice much of a difference in your gas bills? Right now I'm using an electric tank heater, and the bills are ridiculous, as an electrical contractor I already know the most expensive way to heat something is electric. Course I don't tell my customers that. LOL!! My last heater was a gas direct vent that lasted all of 5 years, just off warranty. Nice, I wonder how long it takes them to "engineer" sh!t to brake down just past the warranty. Mini rant over thanks again for the info.

 

[Estevahn]

Installed a Bosch LP unit this spring. I chose it because of the standing pilot. I didn't want to use another power source for ignition. And the pilot is very small and doesn't consume diddly.

Only two dislikes so far.1. one run is very long so the wait kinda sucks. 2.There is a minimum flow to activate the burner so a slow flow will yield cold water. The faucets needed to be near wide open.

I was told that it will need cleaning eventually. It's supposed to be a simple process with vinager. I haven't been there yet.

If you're in a cold climate you'll need to take steps to prevent chimney down draft. It will freeze the heat exchanger. Even if it's in the basement of a two story house this can happen.

I haven't payed much attention to fuel consumption versus our old tank heater. But it's so nice to jump into a hot shower even after two azzhats before you took an hour long shower. It really is endless hot water.

Mine is set so the water is just a little too hot for showering with hot water alone. Just a touch of cold to tame it down. They say that's a waste of fuel but for things like dish washing I want it hot.

They take up very little room too.

I like it!

 

[Estevahn]

Here's a few things that can cause chimny down draft.
Clothes dryer
Bathroom vent fan
Older furnace that uses combustion air that's drawn from inside the house.
It really depends on how tight your house is though.

 

[kraftymike]

I was told by a very smart plumber who had done tons of research, that under normal residential demand they are actualy less efficient than a standard Nat. Gas tank. This has to do with the waisted energy from blow-by durring output. He told me that in a heated mech. area, after a tank heater is brought up to temp, the pilot light alone is all it takes to store the water at temp until it is called for. The never ending supply would be very nice though.

 

[touchofgrey]

Krafty, your plumber might be right, my issue is that I don't have a chimney, and that the direct vent "tank" heaters are as much as the "tankless" money wise. As I said earlier, my last direct vented tank heater only lasted for 5 years, and for the price of them I expect more for my $.

 

[785RMK]

I purchased the biggest Rheem tankless water heater (natural gas). I have only two b%tches about it.

1. If you have a long run it takes awhile.
2. faucets have to be opened up to stay hot.

Make sure that you have plenty of water pressure & volume. Also correct size of gas line.

Other than that it is great, endless showers and if you leave it isn't running. We bought this home this summer, someone had stolen the old water heater. But my gas bill in the summer is $25 with 3 of us living there. We also have a gas stove we use a lot. Our house was at least 50 a month. By the way, the old house was supplied by the public gas company (cheap therms) compared to the private company (expensive therms). Way more efficient.

 

[dragon12]

The length of the run would be the same for both a tankless and tank type heater as long as they are mounted in the same area. The only difference is you must have a movement of water in order to ignite the tankless heater and it then takes approx. 8 seconds for water entering the heater to exit at desired temperature. A Rinnai unit requires a minimum flow of .5 gallon per minute to ignite. This prevents a drippy faucet from causing the heater to run. On the other hand if you shave with a small stream of water you may need to change your ways. Single handle faucets are also a pita because you need to turn them all the way hot and then back them down when hot in order to make the heater ignite. You will basically change your habits when it comes to hot water but many of our customers really like their heaters.

By the way, to minimize the amount of time you wait for water, locate the heater in the middle of the system if possible.

 

[785RMK]

If I were to do it all over again, I would still buy the tankless. It is a sweet system.

 

[Tearupamountain]

This is such a tankless job!