Any RME Plumbers, Thinking about a tankless water heater?

[Brad J]

Our home was built in 1999 and the water heater (A O Smith 50 gallon LP) has some rust and corrosion at he bottom lip. My guess is its on its way out. Our neighbor had theirs open up on them a few weeks ago I'm considering switching to a tankless waterheater. We have 2 bathrooms but are in the planning stages of putting a bathroom in our basement. We have a jacuzzi (50 gallon?, Thank you Lewis) that we will be installing. We run out of hot water on Sunday Mornings when everyone takes a shower one after the other (family of 4). It sucks to be the last one. We have the Polybutylene Pipe and it looks like it would need to have a couple elbows put in it to get it close to the wall to go into a tankless water heater rather than into another 50 gallon water heater. What would this run me to have the pipes changed? Are there drawbacks to the tankless waterheaters? Do I need a high altitude one if at 4240'(?)? How long do they typically last? Are there noticeable savings? Is the EcoSense Home Depot brand ($1k) worth getting?

Thanks, Brad

 

[chadschoon]

ive only put a few in. you'll have to check on your flu as well. the ones I have done have needed a stainless steel '"B" vent flu. I know some can just vent out the wall as well though. I know our service guy has had to go mess with them a few times due to things clogging up. they work well for a few things but I dont think I would run a whole house off one. they seemed to work fast though when they called for heat. by the time you buy one and install it, why not just put 2 40 gallon water heaters in?

 

[jamesgeologist]

I helped a friend install a Takagi TK-3 last week and it was really simple. The flu pipe was a pain, and expensive, but very worth it. Lots of great features like priority hot water if you use radiant floor heating. Really reasonable through the internet. Local plumbing suppliers are making too much profit on these units.

If you are getting corrosion through your unit, the sacrificial anode may be gone. 1 1/16" socket and a new anode and you are good for many more years. BTW, there is an an anode in both electric and gas water heaters.....Don't let that galvanic current bite you in the a$$.

 

[RockMonkey]

I helped a friend install a Takagi TK-3 last week and it was really simple. The flu pipe was a pain, and expensive, but very worth it. Lots of great features like priority hot water if you use radiant floor heating. Really reasonable through the internet. Local plumbing suppliers are making too much profit on these units.

If you are getting corrosion through your unit, the sacrificial anode may be gone. 1 1/16" socket and a new anode and you are good for many more years. BTW, there is an an anode in both electric and gas water heaters.....Don't let that galvanic current bite you in the a$$.

How can the anode be inspected?

 

[Tacoma]

Excellent question, as I am now paranoid that my water tank is about to rust out.

 

[Jedisdead]

mine did last christmas it was 20+ years old lots of rust on the outside looked like a toyota rear fender

 

[bobmed]

http://granger98.blogspot.com/2008/01/heather-ravnikar-darrell-hendriksen.html

http://www.thisoldhouse.com/toh/video/0,,20047047,00.html

 

[del0075]

for a one or two bath house they will work ok, if you do the math they are not legal for much more than that..they work on a flow restriction to keep up with making hot water, they put out about 7 gallons a min. depending on the unit, and your jetted tubs take about 12-15 gallons a min, depending on the valve. as long as you dont run all your tubs or showers and laundry, or any other hot water valves, they work some what. i have installed quite a few of these, some people like em, but i have had more that dont...another problem with em is hard water, put in a softener with it, and it will help it last longer...

 

[Caleb]

...another problem with em is hard water, put in a softener with it, and it will help it last longer...

Isn't that a general rule for all water heaters (tankless or not)

 

[del0075]

Isn't that a general rule for all water heaters (tankless or not)

yes but a tankless builds up deposits faster than a tank type water heater

 

[Brad J]

Thanks guys for the ideas. It looks like its best to get another 50 gallon water heater and put it in myself So could the anode cause rust like this? I hate the thought of the water heater bursting open and ruining our laminate flooring in our newly finished family room:sick: It would end up happening when we're out of town for a couple days since thats how these things work

 

[Jedisdead]

that is what mine looked like. I got some pretty slick connectors to hook it up with out soldering from home depot. way easy dont pay them the 500 dollars to do it

 

[Brad J]

that is what mine looked like. I got some pretty slick connectors to hook it up with out soldering from home depot. way easy dont pay them the 500 dollars to do it

I'm hoping I can get one about the same height w/ the same way to connect it.

 

[waynehartwig]

Tankless is really the way to go if you are going to keep the house longer than a few years.

Bosch makes some really good ones and for about $1500 (been a few years, so I could be off on the price a bit) you can get a large one that will run 3 major items at the same time - ie dishwasher and two showers at once and still maintain.

The gas fired ones need a stainless flue pipe that is very expensive - $1k to put one in isn't too far off. They can also be vented through an exterior wall as long as you meet the requirements when doing so. Some also have a forced air pump that you can put on them that lower the flu temps.

Bottom line if you skimp, you will hate it. But if you buy one big enough for the house, you will love it. They are ALOT more efficient than a tank style water heater.

 

[waynehartwig]

I'm hoping I can get one about the same height w/ the same way to connect it.

...So you only soften the cold water? I would hook it up so the water is softened before it goes into the water heater that way you have both...

 

[jamesgeologist]

How can the anode be inspected?

On the top of the unit there should be an inspection hole with insulation in it. Push away the insulation and use a 1 1/16th socket to pull out the anode. If it is corroded, get a new one, if not, get a new one. They are relatively cheap, but you won't find them at HD or Lowes. Plumbing supply houses are the only places to get them. Standard Plumbing is a good place......

 

[RockMonkey]

On the top of the unit there should be an inspection hole with insulation in it. Push away the insulation and use a 1 1/16th socket to pull out the anode. If it is corroded, get a new one, if not, get a new one. They are relatively cheap, but you won't find them at HD or Lowes. Plumbing supply houses are the only places to get them. Standard Plumbing is a good place......

I've never heard of this. So, how often should I "inspect" (replace) it? It's only about two years old right now. 5 years?

 

[jamesgeologist]

I've never heard of this. So, how often should I "inspect" (replace) it? It's only about two years old right now. 5 years?

The sacrificial anode can last 5 years or 20. It all depends on the "condition" of the water. The premise is that there is a natural galvanic current that happens between the water and the metal tank. There is a glass lining in the tank, but even that cannot fully prevent the current from eroding the tank. The sacrificial anode is just that, sacrificial. It dies slowly over time so your tank does not.

Sacrificial anode
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Sacrificial anode in the hull of a ship

A sacrificial anode, or sacrificial rod, is a metallic anode used in cathodic protection where it is intended to be dissolved to protect other metallic components.

The more active metal corrodes first (hence the term "sacrificial") and generally must oxidize nearly completely before the less active metal will corrode, thus acting as a barrier against corrosion for the protected metal.

More scientifically, a sacrificial anode can be defined as a metal that is more easily oxidized than the protected metal. Electrons are stripped from the anode and conducted to the protected metal, which becomes the cathode. The cathode is protected from corroding, i.e., oxidizing, because reduction rather than oxidation takes place on its surface.

For example when zinc and iron are electrically connected in the presence of oxygen and water, the zinc will lose electrons and go into solution as zinc cations. Electrons released from the zinc atoms flow through metallic conduction to the iron where, on the surface, dissolved oxygen is reduced, by gaining the electrons released by the zinc, to hydroxide anions. Were the zinc not present, the same reduction of oxygen to hydroxide would occur on the iron surface. However in that case the electrons for reduction would be furnished by the iron, thus oxidizing the iron. Therefore, the zinc, when present,is "sacrificed" by being oxidized instead of the iron. The iron is "safe" until all of the zinc has corroded. As zinc is more costly than iron, this method of protecting iron, or steel, would not be cost effective were it not for secondary chemical reactions that form coatings on the iron surface, thus reducing the electrochemical reaction to a trickle and greatly prolonging the life of the zinc anode.

Other examples of protection by use of sacrificial anodes include protection of voids in the glass lining of mild steel water heater tanks via use of magnesium or aluminum alloy anodes, protection of off-shore oil rigs via special alloy anodes for use in salt water, protection of lock gates in water ways, etc.

It is important to understand that for this mode of corrosion protection to function there must be simultaneously present an electron pathway between the anode and the metal to be protected (e.g.,a wire or direct contact) and an ion pathway between the anode and the metal to be protected (e.g., water or moist soil) to form a closed circuit; thus simply bolting a piece of active metal such as zinc to a less- active metal, such as mild steel, in air will not furnish any protection.

 

[zukking01]

I have a Rennai 7.5 gallon tankless and I love it. It was about a grand for the unit and the stainless steel vent with pvc outer was expensive per piece but worth it. I have it mounted above my washer and dryer so it is out of the way and gives heat on demand. I have 2 bathrooms so the 7.5 is good for me but you would want the 9.4 gpm one.

You need to see what the output temp/ gpm is with the street temp. Most are rated around 65F and in winter in Utah we see water alot colder so that kills the gpm at the same temp.

The tankless was easy enough to put in. I put 4 concrete ancores into the wall and mounted the tank. Plugged it into the wall, ran the new flue right out the side of the house, and ran copper to the new location. Really not that hard to do and worth every penny.

 

[del0075]

...So you only soften the cold water? I would hook it up so the water is softened before it goes into the water heater that way you have both...

looks like thats how its plumbed, if you get a big enough unit they work ok, but if you check into the flow rates, they wont handel many fixtures at the same time....