Home Hot Water Heater

[bridgebuster]

My house was built in 1995; we have hard well water, pH~8. My first water heater lasted almost 7 years but since then I've been replacing them every 2 1/2 years. I was wondering if a stainless steel water heater would stand up against hard water. I've seen some ads for tanks manufactured from 316L.

I've thought about softening the water but read that the salt could have negative effects on my groundwater; that's why I'm thinking of a stainless steel tank. Thanks for your replies (I still have 1 1/2 years to go).

 

[EdStainless]

First, shut off your current heater and let it cool, then pull the anode. Is there any left? These Zn/Al anodes should corrode sacrificially in order to protect the tank. You may need to replace them every 12-18 mo in order to keep that part of the system working.
The hardness is not causing the corrosion, unless you are having scale form and getting corrosion under it.
Don't be afraid of water softeners. My current one demand meters so that it only re-gens when needed. I use <200lbs of salt a year which my septic field will easily handle.
Most SS tank units are actually fairly poor quality, there are some very good industrial ones, but they cost a fortune.

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

I would consider an on-demand hot water supply. I had a neighbor install one and when my hot water tank goes on-demand is next.

 

[bridgebuster]

Thank you for the replies.

EdStainless - I never thought about the anodes. It might be worth it to invest in a 3' section of pipe so I can get the bolt loose.

metengr - I did some research a while back on tankless heaters; mixed results. A friend of mine says they have them in his shop but he's less then impressed by them. He said the water is never really hot. Of course every installation is different.

 

[metengr]

Good luck trying to loosen the anode. I have seen problems with damage to the hot water heater tank fitting. Also make sure the water supply and discharge to the heater are valved out to fully depressurize.

 

[EdStainless]

On demand works well if it is right next to point of use, otherwise the temp rise is not great enough.

One house that I lived in also destroy water heaters. I would remove the anode on the new one, coat the threads, and replace it every 12 months.
iron and Mn in the water is tough on them.

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P.E. Metallurgy, Plymouth Tube

 

[DVWE]

EdStainless - I never thought about the anodes. It might be worth it to invest in a 3' section of pipe so I can get the bolt loose.

Spray a liberal amount of penetrating oil on the connection and let it soak for at least 12 hours. Mine came right off with little effort after doing that.

 

[bridgebuster]

My water has a lot of iron in it.

Good point about penetrating oil.

 

[moltenmetal]

Got to get the anode loose when the heater is brand new, so you can get it loose again when it needs replacement.

I have a tankless water heater- stainless steel internal construction. No corrosion or scaling problems so far, but we have rather beautiful lake water as a supply.

 

[blacksmith37]

Somewhere in the heater instructions it says to "blow down" twice a year. This is especially important in hard water, especially "temporary" hardness. I have a more corrosive water and get 15+ yrs. Also a plumbing supply supply should have better quality heaters than the "big box" stores.

 

[bridgebuster]

moltemetal - The tank is a year old; hopefully I can get it loose.

blacksmith37 - what brand water heater do you have? My last 4 and the current one have been Bradford-White. Several years ago the plumber swore it was the best after he replaced the big box GE that I previously installed. Some years back I started to drain gallon or two every month but it doesn't seem to make a difference.

 

[weldstan]

Had very hard water and used a water softener. Water heater life was 10 years.

 

[Compositepro]

To flush a water heater you need to open the drain valve full blast for a couple minutes. The incoming cold water must have adequate velocity to lift the sediment off the tank bottom. The cold water inlet is at the top of the tank, but there is a dip tube on the inlet so the water actually enters the tank very close to the tank floor.

 

[EdStainless]

One reason that tankless may hold up better in difficult water is that they continually flush themselves.
I used to drain some water four times a year, and gave it up when I got my new softener.
Old heaters were worse for having 'hot spots', and since most minerals are less soluble in hotter water they would scale.

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P.E. Metallurgy, Plymouth Tube

 

[moltenmetal]

The reason used to justify the tankless to my wife was the ability to fill the big tub without having to do it in two tries with a 1/2 hour wait between for the (single) tanked unit to catch up.

The real reason was efficiency, and a government program that made the upgrade basically free other than my own labour to install it.

I might install a small tank downstream of the tankless one day, to be turned off in summer but turned on in winter- it annoys me how much water you need to waste if you really need to wash your hands in hot water. Some of our hot water lines are pretty long, and it takes quite a while running a sink faucet for the water to get hot.

 

[blacksmith37]

i have something called "State Select", I didn't see other info. I think the internal coating properties and anode are important to the life ; I have no idea what is in mine.

 

[bridgebuster]

Thanks Blacksmith37

 

[EdStainless]

MM, tankless and efficiency? They save the energy that it takes to hold the water hot, but the gas fired ones that I looked at were much less efficient than my tank unit. The electric ones may be another story.
I have a neighbor that has three tankless units spread around the house, near each point of use.

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P.E. Metallurgy, Plymouth Tube

 

[bimr]

moltenmetal,

There are recirculating pumps that are used to save water.

http://us.grundfos.com/products/find-product/up-10.html

 

[moltenmetal]

Regrettably you either need a return line or you need to use the CW line as a return line- these are tough to retrofit after the fact. But combined with a very small under-sink type hot water storage tank, operated only in winter, a little recirc pump could save me some water. There's a point where I could run a recirc line without breaking out any drywall, but quite a few fixtures are still a fairly long run of PEX tubing from that point.