Advice - Tankless Water Heaters !

SourKraut · Mar 31, 2008

SR denny. Thanks for your reply.What do yurupeans use to heat their homes? I realize a lot of them do live in multi-family units with a common heat source. But there are a large number of single family dwellings as well. I remember visiting my grandmother in Germany back in the 80's having a tankless heater for the domestic water and cast iron radiators for their heat source.
I'm curious as to what sort of maintenance is required for the tankless. I feel a little foolish for finding this site after the fact of installing a Rannai unit. I live on Long Island where the water is very good. I am not aware of any contaminants that would clog our plumbing. If so what sort of precautions should I take as the system is only used for heating the floors so half the year it won't be operating.
I also interested as to what "extra plumbing"(other than a gas line) is needed for the tankless vs the tank type? Outside of the floor heating loops there seems to water in, water out, gas supply.

Jadnashua · Mar 31, 2008

Many of the tankless systems are not specified for use as area heating devices...unless that one is, you may not have a warranty.

When used to heat domestic water, you are constantly supplying new water with its dissolved minerals in it. The intense heat in the heat exchanger can cause those minerals to be deposited on the insides of the heat exchanger. If the coating gets deep enough, it acts like an insulator and your heat transfer can suffer radically. I don't think your system when used to heat the house in a closed loop system will run into those problems...wearing out the unit that wasn't designed for potentially 100% duty cycle is.

Sponsor · 2022-01-29T12:20:58-0800

Squ1rrel · Apr 1, 2008

I would agree with Jad on the duty cycle thing. Seeing that copper heat exchanger burned through like someone took a cutting torch to it from overuse is NOT a pretty sight. I wonder if some of these new, stainless steel systems are going to run into the same problems?

SRdenny · Apr 2, 2008

to the others debating merits of tankless technology versus tank technology - I consider the "newfangled, more complicated, and not yet widely adopted" tankless technology as compared to the older, more widely adopted tank heater technology to be analogous to computer-controlled fuel injection technology when it came strongly into play in the automotive industry around the 1980's, displacing the previous carburator / air-fuel fuel mixing technology. Fast forward 20 years since then, and sure the technology is still more complicated than carburation, but has been made acceptably reliable and the knowledge of maintenance procedures and repair has become widespread enough to allow nearly all automobiles manufactured nowadays to employ the new technology. In fact there may now be more mechanics / auto-technicians now knowledgeable in servicing fuel injection vehicles than there are who are able to rebuild and repair carburators. We may see a similar market adoption trend with water heater technology in the future. In this case the new technology will become more widespread and accepted, as the price comes down to purchase and maintain it, and it becomes better "tested" and improved, etc.[/QUOTE]

Your analogy may come to pass. If it does, I'm sure there will be some product variation as the manufacturers adapt to the marketplace, as well as incorporate evolving technology.

SRdenny · Apr 2, 2008

"I live on Long Island where the water is very good. I am not aware of any contaminants that would clog our plumbing. If so what sort of precautions should I take as the system is only used for heating the floors so half the year it won't be operating. The water where I live is very good as well, but it still has inpurities. I would recommend checking the filter on the incoming cold side of the heater on a by yearly basis, at least for the first year.
I also interested as to what "extra plumbing"(other than a gas line) is needed for the tankless vs the tank type? Outside of the floor heating loops there seems to water in, water out, gas supply." The flue requires Cat III (stainless steel) pipe, with a condensate drain.
__________________

plumbernj · Apr 2, 2008

jakeru said:
to the original poster - I think the Takagi and Rinnai brands are both exceptionally high quality tankless heaters. The Takagi TK-3 has a low .5 gpm turn-on flow. I am very happy with mine. I saved a bundle buying it all on secondary market (craigslist) or wholesale and installing it myself.

to the others debating merits of tankless technology versus tank technology - I consider the "newfangled, more complicated, and not yet widely adopted" tankless technology as compared to the older, more widely adopted tank heater technology to be analogous to computer-controlled fuel injection technology when it came strongly into play in the automotive industry around the 1980's, displacing the previous carburator / air-fuel fuel mixing technology. Fast forward 20 years since then, and sure the technology is still more complicated than carburation, but has been made acceptably reliable and the knowledge of maintenance procedures and repair has become widespread enough to allow nearly all automobiles manufactured nowadays to employ the new technology. In fact there may now be more mechanics / auto-technicians now knowledgeable in servicing fuel injection vehicles than there are who are able to rebuild and repair carburators. We may see a similar market adoption trend with water heater technology in the future. In this case the new technology will become more widespread and accepted, as the price comes down to purchase and maintain it, and it becomes better "tested" and improved, etc.

Yeah, I heard this same jargon in 7th grade about the metric system.

Squ1rrel · Apr 2, 2008

And yet, the US is one of the only countries remaining to use the Imperial Standard measurement..but measurement changes requires the entire system to change, technology alters gradually, as it increases in reliability and availability, and people replace their older systems...just look at cell phones and laptops. Convenience and durability exceeded problems as the technology progessed.

Redwood · Apr 3, 2008

Many of todays cars with all these newfangled electronic fuel injection, electronic ignition are routinely going 100,000 miles before they ever have a mechanic do anything more than an oil change and other required maint.

I don't miss those 15,000 mile tune ups a bit! Seems like there is none of that getting the choke right either. What I really like is being able to do a performance tune with a laptop or after market plug in box! One of my buddies has a one ton GM diesel van that will make a corvette owners eyes bug out when he gets left behind at a traffic light!

Technology is a wonderful thing!

Jed1154 · Apr 3, 2008

I have three electric tankless water heaters. I like them.

Advice - Tankless Water Heaters !

Users who are viewing this thread

SourKraut

New Member

Jadnashua

Retired Defense Industry Engineer xxx

Sponsor

Paid Advertisement

Squ1rrel

New Member

SRdenny

Plumbing Contractor

SRdenny

Plumbing Contractor

plumbernj

In the Trades

Squ1rrel

New Member

Redwood

Master Plumber

Jed1154

Member

Similar threads