Tankless water heaters

[talisman]

Any experts on these things? I've love to free up the garage space that huge mfer of a water heater is taking up, and the tankless jobs are supposed to be very efficent and save 10-15% on your electric bill. That sound realistic? It would be electric and not gas. Looks like I'm going to be spending somewhere around 5-700 bucks?

[FSON]

We spec them at work for public restrooms, no complaints, that is good.
You will need one at each use and remember new elec wiring and plumbing.
There is no single central unit available that will take the place of your existing water heater. This would require a huge power draw.

[talisman]

You can't just buy 1 central unit and stuff it in the garage? Fuck that!

[FSON]

You can't just buy 1 central unit and stuff it in the garage? Fuck that!
I asked one of the manufacturers that very question. They hinted there are some made by another manufacturer but it is for commercial use...probably uses more energy than what you already have.

[Big Studly]

Any experts on these things? I've love to free up the garage space that huge mfer of a water heater is taking up, and the tankless jobs are supposed to be very efficent and save 10-15% on your electric bill. That sound realistic? It would be electric and not gas. Looks like I'm going to be spending somewhere around 5-700 bucks?

I am not a big believer in them. Especially the electric ones. They use a lot of energy actually because you are trying to heat water from 60F to 180F at a specific flow rate instead of heating a mass a few degrees several times a day to maintain a specific temperature.

I think they are better served up north in colder regions where your garage stays very cold most of the year, here in Texas, your garage stays hot most of the time, so you aren't losing as much heat out of the water heater as some place in the North, so you aren't seeing the full benifit.

I love these blanket "save xxx% off your electric bill" these dumb mother fuckers try and use for these water heaters, radiant barriers, heat reflecting paint, etc....I guess it is good that the world is full of morons to fall for that shit or they would be out of business.

[Big Studly]

You can't just buy 1 central unit and stuff it in the garage? Fuck that!

by the way, no you can't....the flow rates are so low, because it takes so much energy to heat up the water that they can't make them any bigger or they would probably have to be run off of 460V/3 phase, which no body in their right mind would put in their house. You need multiple units for even the smallest of houses.

[FSON]

I am not a big believer in them. Especially the electric ones. They use a lot of energy actually because you are trying to heat water from 60F to 180F at a specific flow rate instead of heating a mass a few degrees several times a day to maintain a specific temperature.

I think they are better served up north in colder regions where your garage stays very cold most of the year, here in Texas, your garage stays hot most of the time, so you aren't losing as much heat out of the water heater as some place in the North, so you aren't seeing the full benifit.

I love these blanket "save xxx% off your electric bill" these dumb mother fuckers try and use for these water heaters, radiant barriers, heat reflecting paint, etc....I guess it is good that the world is full of morons to fall for that shit or they would be out of business.
For the non engineering types, heating only at use seems to make more sense than keeping the water hot 24/7, no?

[Sgt Beavis]

You can't just buy 1 central unit and stuff it in the garage? Fuck that!

Not if you want Electric. Gas can handle it though.

I don't think you can enough heaters for your home at that pricing either. Gas ones can cost several thousand. Rinnai tankless water heaters cost about $3000. Even though they are excellent quality (my In Laws have had theirs for nearly 20 years)

[Big Studly]

For the non engineering types, heating only at use seems to make more sense than keeping the water hot 24/7, no?

it depends, there are too many variables. Temperature rise, heat loss out of the tank (which again varies on the time of year and location), usage, etc..

[Vertnut]

I have tried the electric units, and I would say I give them a BIG thumbs down, especially in a "retrofit" situation. You would need to hire an electrician to install a 80amp dedicated circuit (and the wiring) to run one, plus the cost of the heater, plus it is VERY difficult to regulate between "hot"&"cold". Propane units are 10X better. I just built my own personal home, and I went with 2-70 gallon Ruud units that ran about $300 each. :cool: Propane is expensive, and so are the units. I'm not sold on them either. I would have needed 2 Renai units, and I won't live long enough to recover the cost of those.

[8mpg]

Id only go with tankless on a NEW build with gas only. The electric ones are supposed to suck and need a high amp line ran to them. With a retrofit gas line, most of the time a new gas supply line is needed because they are not big enough. My parents wanted to replace their tank water heater (gas) with a tankless and it was going to run over $3000 to replace one of them

[doopie]

I used 2 Rinnai smaller propane heaters on each side of our house and have no issues. Water takes 10 seconds to get hot in the winter and around 3 seconds in the summer. We can fill up a Spa tub in the bathroom to the top with 138 degree water or the kids bathtub with no loss in temperature. We can set the temperature via remote to within 2 degrees. Wife likes it for the pot filler on the stove as she is able to fill it with hot water and it comes up to temperature quickly

As you can tell it is effected by source temperature as it has to heat the differential.
The only disadvantage to the tankless than our previous high efficiency tank is that my wife and daughter take 20 minutes in the shower now that the water does not get cold at all so I am sure we are using more gas than usual. But I think a relay is in the future to shut it off after 10 minutes :)

Since the original post is about electric I would think that tankless would be a no go and you should just get a high efficiency unit with a timer to shut it off when you are not showering. just need an override when you shower outside the timer window though and any electrician should be able to hook that up.

Raymond