Tankless water heaters...anyone have one??

mrrman

Diamond Member
Feb 8, 2004
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I have had 3 major water disasters in my house within the last 2 years totalling $25K and now I have had it with things that break down/blow up. I am now thinking of replacing my hot water tank with a tankless one before this blows up. Does anyone have one. I have 3 showers in my house so I am looking at options right now. Thanks
 

mshan

Diamond Member
Nov 16, 2004
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HVAC guy was tuning up my air conditioner and mentioned that you can apparently have a shut-off valve that detects water in drip pan hot water heater is in and can shut off water supply if it detects leak (still may not protect against whole water heater bursting catastrophically, but that would presumably because you got true lemon from factory or you had old water heater that was leaking for a while that you didn't notice and eventually burst).

Problem with tankless I've read in past was if say multiple people are trying to draw hot water at same time and tankless can't up with required amount of heating required.

Personally, I like State Industries water heaters because they advertise as being durable and reliable, but have really competent plumber install might also matter.
 

wirednuts

Diamond Member
Jan 26, 2007
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yeah if i did tankless, it would be one unit at each sink. that way multiple people using hot water wouldnt effect anything. but you have to have the power at each sink to do it....
 

sixone

Lifer
May 3, 2004
25,030
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I used to have one, but have moved since then.

It was advertised to supply two water sources at a time, such as dishwasher and shower, washing machine and sink, whatever combo you can come up with. But usually, we ended up with two sources of warm water, and no hot until we turned one off.

It also took a while to get hot water to some faucets/showers, because the hot water in the pipes had cooled.

We went from an old, inefficient tank to the tankless heater. It cut our gas bills by 75%. I'd like to get a new one, but wow...they're expensive. :(
 

Vic Vega

Diamond Member
Sep 24, 2010
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I have a gas unit from Rinnai, 9.8 GPM. Works well, so far I haven't been able to "saturate" it. We have three full baths in the house and had them all in use at once during the holiday last year (my parents, plus inlaws - or outlaws as I like to call them, plus my wife and kids), with no issues. I do have low flow shower heads in all the showers.

I can't remember but I think there is still a Federal tax credit on them, not sure. My unit goes for around $1,200 but you can find it on sale if you look.
 

Caecus Veritas

Senior member
Mar 20, 2006
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rinnai tankless water heaters are pretty reliable. also, 1 per sink is not the correct way. there are multiple variables to consider: BTU of heater / number of sinks/showers/tubs etc / location and distance from heater.

there's an easy chart that shows how many showers a particular model can sustain. 199,000 BTU should be okay for 3 showers + kitchen. but depending on the piping length and location, 1 tank may not be sufficient. you may want to split the supply into 2 zones.

also, tankless water heater takes a bit for the water to heat up. usually tolerable. however, if you wish to have instant hot water, then you need to add another loop with a small heater to keep hot water circulating. typically not worth it.
 

slsmnaz

Diamond Member
Mar 13, 2005
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Sold them for a long time and have a Rinnai (external model) in my house. We have a smaller house but have had no issues with hot water running out if being used on multiple fixtures. You have to get it sized properly for each application and that could be the problem many run into. Best part is we were able to get rid of a large tank heater in our house and add an extra 1/2 bath.

Couple of issues from our house:

- gas line had to be redone to accommodate heater (and new gas line to range). Cost about $1100
- way the water was run in our house made a small wait for hot water at the kitchen sink. Small point-of-use at this fixture could fix it but haven't installed yet
- Expense. The heater is much more expensive than a tank type and so is installation. Not sure everyone will recoup the costs but us adding a 1/2 bath made it worth it
 

bignateyk

Lifer
Apr 22, 2002
11,288
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If you have more than one person living with you you're gonna have a bad time. They can't keep up with the demand of multiple showers running. There's times when we have the dishwasher, washing machine, a sink, and a shower going at the same time.

The best case would be some kind of hybrid with a small tank in combination with a tankless heater so that if it couldn't keep up with the demand you would have like 10 gallons of reserve hot water or something.

If you could demonstrate to me that a tankless unit could keep up with two showers running at good pressure/flow and an appliance like a washing machine running simultaneosly I'd consider it if it were cheaper. Right now its way too expensive to install.
 
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Vic Vega

Diamond Member
Sep 24, 2010
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If you have more than one person living with you you're gonna have a bad time. They can't keep up with the demand of multiple showers running. There's times when we have the dishwasher, washing machine, a sink, and a shower going at the same time.

The best case would be some kind of hybrid with a small tank in combination with a tankless heater so that if it couldn't keep up with the demand you would have like 10 gallons of reserve hot water or something.

What? No. You didn't size your unit properly and are complaining it can't keep up with a load that is obviously out of its class.

See my post above, I have a 3.5 bathroom home and have no issues.
 

Xecuter

Golden Member
Aug 17, 2004
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Eh...I've got one. Supply isn't an issue - we can have the dishwasher and showers and whatever running and hot water will come, it's the wait for the hot water to come; specifically through faucets. We can be waiting 30+ seconds for hot water to deliver.

I know, first world problems. I believe you can get a ~10 gallon tank as a reservoir and that will solve the waiting problem but I haven't investigated yet.

EDIT: Also expensive as hell
 

bignateyk

Lifer
Apr 22, 2002
11,288
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Eh...I've got one. Supply isn't an issue - we can have the dishwasher and showers and whatever running and hot water will come, it's the wait for the hot water to come; specifically through faucets. We can be waiting 30+ seconds for hot water to deliver.

I know, first world problems. I believe you can get a ~10 gallon tank as a reservoir and that will solve the waiting problem but I haven't investigated yet.

EDIT: Also expensive as hell

By the time you add another tank you've lost some of your efficiency anyway. A big tank water heater is so cheap compared to a tankless unit and they last 8-10 years if you have soft water and maintain them properly.

The unit itself costs more, but most likely you'll end up spending a ton of money doing the retrofit installation. It would take a long ass time for it to pay for itself vs buying a new 50 gallon tank heater.
 

PsiStar

Golden Member
Dec 21, 2005
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I have a Navien on nat. gas for domestic hot water + base board heat; 3.5 baths, & 2 kitchens (have a prof. chef in the house). There has never been a hot water supply issue. It has been in a little less than a year and has saved hundreds $$ over fuel oil already ... not to mention getting rid of the mess of oil. I vaguely remember it was ~$1200 installed but also included the extraction of the oil tank & old boiler.

According to the installers, a very important installation trick is a short loop about 4' X 2' that helps to stabilize the supply temp.
 

slsmnaz

Diamond Member
Mar 13, 2005
4,016
1
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Eh...I've got one. Supply isn't an issue - we can have the dishwasher and showers and whatever running and hot water will come, it's the wait for the hot water to come; specifically through faucets. We can be waiting 30+ seconds for hot water to deliver.

I know, first world problems. I believe you can get a ~10 gallon tank as a reservoir and that will solve the waiting problem but I haven't investigated yet.

EDIT: Also expensive as hell

you can always add a small point-of-use heater to the sinks where it is a problem. It kicks on immediately and shuts off once the temp is high enough from the main heater. Likely easier and cheaper than adding a tank
 

Garet Jax

Diamond Member
Feb 21, 2000
6,369
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71
I have had 3 major water disasters in my house within the last 2 years totalling $25K and now I have had it with things that break down/blow up. I am now thinking of replacing my hot water tank with a tankless one before this blows up. Does anyone have one. I have 3 showers in my house so I am looking at options right now. Thanks

Yes I have a whole house one.

I bought this

http://www.buyplumbingnow.com/GU_195_S.html

a few months ago and love it. It takes a little longer for hot water to get to the taps (because the unit has to turn on, heat the water and then get it to you.

I did this because the water heater with the house was too small.
 

AMDMaddness

Platinum Member
Sep 1, 2003
2,406
2
81
I have a Rinnai tankless water heater with 3 kids and two adults it keeps up just fine. I can have two hot showers going at a time and do laundry and wash my hands with plenty of hot water to spare... I think there are far to many myths about tankless water heaters.
 

bignateyk

Lifer
Apr 22, 2002
11,288
7
0
I have a Rinnai tankless water heater with 3 kids and two adults it keeps up just fine. I can have two hot showers going at a time and do laundry and wash my hands with plenty of hot water to spare... I think there are far to many myths about tankless water heaters.

Gas tankless units seem to have good capacity. Electric ones are pretty terrible. The best electric unit I've found so far is this one:

http://www.stiebel-eltron-usa.com/techdata_tempra_tempraplus.html

Even with the highest capacity unit it's barely usable with more than one shower running, and you need a 300A main breaker for it.
 

Garet Jax

Diamond Member
Feb 21, 2000
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71
By the time you add another tank you've lost some of your efficiency anyway. A big tank water heater is so cheap compared to a tankless unit and they last 8-10 years if you have soft water and maintain them properly.

The unit itself costs more, but most likely you'll end up spending a ton of money doing the retrofit installation. It would take a long ass time for it to pay for itself vs buying a new 50 gallon tank heater.

That is true - cost is definitely higher with a tankless water heater especially to be able to support a whole house.

I had that choice to make (between adding another 50 gallon tank and adding a tankless water heater). I decided to go tankless because a second tank would take up twice the space, double the likelihood of failure, cost twice on energy and double the cost of maintenance.

I could have gone for a cheaper tankless water heater and risked not getting one capable of keeping up with our need. Obviously it made no sense to do that since that was already the problem I had and the last thing I wanted to do was to safe $600 only to have the same issue.
 

Garet Jax

Diamond Member
Feb 21, 2000
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71

bignateyk

Lifer
Apr 22, 2002
11,288
7
0
Yup - agree with that.

There was no question I was going gas.

We don't have natural gas, so I'd have to use propane.

I have a small 100 gallon propane tank for my gas range and gas decorative fireplace, but I wouldn't want to be dependent on it for my water heater. The cost varies way too much around here.
 

Garet Jax

Diamond Member
Feb 21, 2000
6,369
0
71
We don't have natural gas, so I'd have to use propane.

I have a small 100 gallon propane tank for my gas range and gas decorative fireplace, but I wouldn't want to be dependent on it for my water heater. The cost varies way too much around here.

Yeah - that would be a reason for me not to do it. If you run out of propane, then you run out of hot water - not good.
 

NetWareHead

THAT guy
Aug 10, 2002
5,847
154
106
Gas tankless units seem to have good capacity. Electric ones are pretty terrible. The best electric unit I've found so far is this one:

http://www.stiebel-eltron-usa.com/techdata_tempra_tempraplus.html

Even with the highest capacity unit it's barely usable with more than one shower running, and you need a 300A main breaker for it.

:eek: 300 Amps! :eek: Wow. Electric would have to be dirt cheap for me to get one of those. And to run a 300 amp main to this heater would probably be thousands in installation and upgrading. I hate the cost of propane but if I didn't have natural gas and was thinking about a tankless heater, I'd do propane in this case.
 

sdifox

No Lifer
Sep 30, 2005
99,566
17,627
126
tankless is the norm in europe and asia... only in NA is the watertank prevalent.