Tankless water heater

[discusfire4]

Has anyone used a tankless water heater or a point of contact water heater to heat incoming water from their storage tank?

I do not have room to bring in my water tanks during the winter and I am considering purchasing small tankless water heater to put inline between my water tanks and my tank. As the water comes from the tanks that are outside, the water runs through the heater and then it will go through out my tanks.

Any suggestions or ideas?

[scolley]

I've got several in-line water heaters - all Hydor 200 watt and 300 watt models. But I use them in-line for my canister heaters.

I do add cold tap water to my discus tank (run through a carbon matrix to strip out chlorine). So I thought about what you are suggesting, putting them in-line to the line that feeds my tank, to pre-heat the water.

I ran some tests and found that the 300 watt heater would only raise the water temp about 5 degrees, at the flow rate I was using - 7 gph. That was clearly inadequate when in the winter my water is going to be 30 degrees (or more) lower than my tank.

So instead of running multiple in-line heaters on that tap, I just added multiple in-line heaters on my canister, running in parallel. So now, with excess heating capacity under "normal" conditions, it dips about a degree during a fill operation. But due to the excess capacity, it never dips below that.

In summary, I think if you test you will find that short of a REAL slow fill rate, in-line heating might be inadequate to your needs. Money invested in "excess" heating capacity to your tank might be better spent, and more effective.

But if you find a better solution, I'm all ears. Good luck.

[RandalB]

I think he's talking about a standard hot water heater like Takagi or Aquastar (Rheem, Bosch, etc). I used to use one to fill my discus tanks at my old place (Water was good out of the tap..) and heat the whole house's water supply. They are an awesome replacement (25% savings on my Gas Bill!) for a tank water heater and I made sure to have one installed in my new place. I highly recommend them.

As far as heating water for tanks, Maybe a little overkill unless you have a large system. They are perfectly capable of heating water from 40F to 140F at 3.0 GPM or higher depending on the unit. You could very feasably heat the water from your storage tank with no problem. You just need to maintain .75GPM flow to keep the unit operating.

HTH,
RandalB

[discusfire4]

Yeah I was referring to the type that Randal is talking about. I cant bring in my tanks in the winter, but I have it plumb to come in and go through the heater, then to the discus tank. Water stored outside stayed around 45 degrees. If I put the inline household tankless heater, I can raise it to a temperature suitable for my fish.

[scolley]

I think he's talking about a standard hot water heater like Takagi or Aquastar (Rheem, Bosch, etc). I used to use one to fill my discus tanks at my old place (Water was good out of the tap..) and heat the whole house's water supply. They are an awesome replacement (25% savings on my Gas Bill!) for a tank water heater and I made sure to have one installed in my new place. I highly recommend them.
No, I'm talking about these (http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18532/si1382457/cl0/hydoreth300inlineheater300w)Randall - plain old in-line aquarium heaters. And they can't do the job. Not the level of temp differential this requires - not on a single pass.

[White Worm]

Tankless water heater is a great investment and I would suggest getting one that can run two water sources at once. You can have this unit heat all of your household water needs and you could run a line off it for your tanks. You could actually run a line off your pressure relief since tankless water heaters need one.

[discusfire4]

No, I'm talking about these (http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18532/si1382457/cl0/hydoreth300inlineheater300w)Randall - plain old in-line aquarium heaters. And they can't do the job. Not the level of temp differential this requires - not on a single pass.

Im glad that works in your application. By the time I purchase one 110v tankless heater, I will save a few bucks and have plenty of electrical outlets leftover.

[alpine]

If you buy a tankless water heater before dec 31st you can get a $300.00 full tax savings . The exhaust for the installation is very expensive unless you can install in a wall that you can go through to vent to outside. The exhaust is very hot with a tankless heater and they have to be double wall or even stainless..
I heard propane ones are very cost efficient but have never seen one yet.
I looked into getting one earlier this year but do not have the extra cash now to do it.
Good Luck,
roberto.

[discusfire4]

Im looking at an electric one that runs on 110v. Small enough to what I need to run. It does have copper in it. Would that have that much effect on my water? I could put a carbon block on the heated side.

[RandalB]

Don't worry about the copper, that's what your pipes are, more than likely...

Freshwater fish aren't generally effected by copper unless you have massive amounts (OD'ing on meds for example). Invertibrates and some saltwater fish, you may have a concern. As an aside, I filled my discus tanks for more than 2 years with a tankless water heater with no problems.

As far as the electric ones go, they aren't as efficient as the gas ones, but I've never had personal experience with them...

HTH,
RandalB

[dumfatnhappy]

Don't worry about the copper, that's what your pipes are, more than likely...

Freshwater fish aren't generally effected by copper unless you have massive amounts (OD'ing on meds for example). Invertibrates and some saltwater fish, you may have a concern. As an aside, I filled my discus tanks for more than 2 years with a tankless water heater with no problems.

As far as the electric ones go, they aren't as efficient as the gas ones, but I've never had personal experience with them...

HTH,
RandalB

the only real concern I have about going tankless is the heat gain fom the unit itself. It puts off alot of btu's so finding the right place to install can be costly (as mentioned before)

dum

[White Worm]

I think the heat issue is not as much as you would think, especially with a smaller unit. I have mine installed right on the garage wall next to where my old water heater used to be and I just tapped it into my heater / furnace ducting which is in the garage right next to it. Easy to do with some of the cool attachments with metal ducting. Has been working perfect since I have had it 2.5 years.
It only operates when there is a demand for hot water and I have not noticed any major heat increase in the area of the unit or the ducting.

[RandalB]

The one I have has a digital controller so I can set the temp for output.. A nice option.

As far as heating up the room, again, I've had no experience with the electricals, don't know if they need venting or not... I know the Gas ones crank about as much as a normal water heater...

RandalB

[dumfatnhappy]

I think the heat issue is not as much as you would think, especially with a smaller unit. I have mine installed right on the garage wall next to where my old water heater used to be and I just tapped it into my heater / furnace ducting which is in the garage right next to it. Easy to do with some of the cool attachments with metal ducting. Has been working perfect since I have had it 2.5 years.
It only operates when there is a demand for hot water and I have not noticed any major heat increase in the area of the unit or the ducting.

yeah I agree the garage is perfect. My current 50 gal. is in the basement under the stairs next to a bedroom.....SO....I'm not sure how to evac that stairwell.. etc....

I appreciate your coments

[White Worm]

Yes, mine has the adjustment but its not digital :( Just the old..turn it till it points to the higher flame sticker :p It can put out some hot showers though at about 3/4. I just wish I would have spent the extra for the unit that puts out more gph for two household sources at once. I can still use other things but pressure drops alot.