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Old 05-05-2012, 08:58 AM   #31
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I would think the biggest issue with you chosen location would venting the flue gasses. A high eff unit runs on a slope horizontally and it looks like your only choice is straight vertical.

I would just replace what you have with a tankless if that is your choice where you have it now, then all you have to consider is the gas service to the unit.

The cold water sandwich is inherent to the way a tankless operates and the only way around that is a holding tank with a recirculation pump, something I am sure you don't want to get into.



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Old 05-05-2012, 02:35 PM   #32
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I did a lot of research into tankless....

What I basically concluded....the payback on gas is not there. If your doing electric...worth it...but gas? No....about the time you start to save money on gas....the unit is reaching the end of it's life. Additionally, they require more maint than a tank heater.

If the delay in getting cold water is your main concern....then consider a recirc pump.

I'll be moving my 50 gal in a couple of weeks to it's new spot which is about 15' closer to the center of action than before...but I also think I'll add a circulation system...on a timer. Only needs to circulate in the morning and evening....
Even if you are on the right track, you will still get run over if you just sit there.

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Old 05-05-2012, 09:01 PM   #33
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Originally Posted by Jackofall1
I would think the biggest issue with you chosen location would venting the flue gasses. A high eff unit runs on a slope horizontally and it looks like your only choice is straight vertical.
The venting can be either horizontal or vertical. The purpose of sloping the horizontal venting is to allow the condensate to drain back to the unit.
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Old 05-05-2012, 09:29 PM   #34
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Actually, placement and the piping insulation are the biggest reasons why I was considering it.

It does take several minutes to get hot water, even at the sink. None of the pipes are wrapped, so turning off the water while washing dishes means it'll be cooled a bit by the time you run it back on. And that's the shortest run at about 16 feet, IIRC. Opening up all that drywall isn't an option I'm considering right now.

But I really want that space from the tank back. I'd gladly give up the space for Point of Use units at each tap (so total 4). Do reliable point of use gas units exist that do not require venting? Electrical might be out oft reach because my service is only 100A.


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