Flushing Hot Water Tank

[5030]

I get the chunk issues as well, why I took the cheap drain valve off the tanks (one is electric and one is propane and replaced them both with full port WOG valves and I stick a wire clothes hanger up the valve opening and break up the chunks every few months. The drain valves manufacturers install on new tanks are useless. Got a pinhole in one and replaced it.

We all cannot have good water and no we don't drink it. We drink bottled water, usually distilled. Our water is so bad if you make coffee with it and add creamer, it curdles. Don't wash down equipment with it either. I have 2 IBC totes hooked to the gutters on the shop I use for washdown water. Using our well water for washdown leaves everything with a nice white calcium film.

I've never replaced an element on the electric one yet and I attribute that to draining it regularly, usually when I renew the whole house 5 micron cartridge filter which is monthly. I also add H2O2 to the raw water via a positive displacement pump. I use a Cumo industrial filter housing that tales 20" filters.

 

[CobyRupert]

I have calcium too, but never developed any pin holes (knock on wood). Ever check your water’s pH? Seems like it would have to be away from neutral to get pinholes? IDK, maybe not? I never have but would be curios to see how it compares.
I guess with 4 “hot water” heaters, 3 located in places that make flushing extremely difficult, that’s why I run them to fail (bottom element buried in deposits), and deal with each of them 2 hours every 10 years, rather than 2-4 hours every month. Although flushing would probably save the elements.

Other than water’s pH, dissimilar metals in contact (say copper piping with a steel tank or galvanized pipe, etc.. can cause galvanic corrosion that shows up a pinholes. Many “hot water” heaters have a sacrificial anode that will dissolve or use brass connections to isolate different metals. I’ve never checked on, located or replaced an anode…. but maybe I should?

P.S. Answer: You put “bread” in a toaster. Bread, not toast. Sort of like a hot water heater doesn’t heat hot wa…. oh never mind!

 

[Doofy]

I have noticed on a couple of occasions that iron bacteria will badly pit and eat away at the submerged portion of a galvanized submersible well drop pipe.

Even tho most water heaters say they are "glass lined" (whatever that means) I am sure that are several chemical reactions that can eat away a tank.

 

[ponytug]

While pH can be a factor, it is more common for naturally soft waters to be lower in pH, i.e. acidic, and they tend not to be a problem for pipes or water heaters as the amount of dissolved acid (ionic strength) also tends to be low.

More commonly, high ionic strength water (aka "hard" water, or brackish water) tend to be hard on water heaters due to galvanic corrosion. There are many different kinds of "hard" water, some precipitating on heating, some not. Softening the water keeps sediment from forming, but there is still the problem of all the dissolved salts making an excellent conductor for galvanic corrosion, e.g. between the steel of the water heater and the copper piping, but also between one part of the water heater and another.

The general problems with sediments are that they can make gas fired water heaters much less efficient and by trapping water in pockets under sediment can worsen the effects of galvanic corrosion and the effect of sulfur eating bacteria that produce hydrogen sulfide which leads to local pockets of sulfuric acid. It is less of a problem in electric water heaters, but tends to cause a rapid burn out of the electrode when it gets covered due to overheating, not to mention the loss in hot water storage.

A "glass lined" water heater has had a glaze of glass powder/slurry applied and then melted in place, like the enamel on a washing machine or stove. The enamel is a hard, durable coating. It is hard to make the coating perfect though, so with time the defects in the enamel coating are where corrosion starts and eats through the steel of the water heater tank. If you have ever cut open a leaking water heater, it tends to have an almost perfect enamel coating, with just a place or two where it failed, often on the welded seams. Whether the failure points are a result of a defect of welding, or just a failure point due to dissimilar expansion causing an enamel failure, I have no idea.

Stainless water heaters exist, but they are just stain-less, not corrosion proof, and suffer from an even lower thermal conductivity than steel, which is much lower than copper, or aluminum, which means they tend to be less efficient.

All the best,

Peter

 

[Doofy]

Excellent explanations. Thank You.

 

[lman]

While pH can be a factor, it is more common for naturally soft waters to be lower in pH, i.e. acidic, and they tend not to be a problem for pipes or water heaters as the amount of dissolved acid (ionic strength) also tends to be low.

More commonly, high ionic strength water (aka "hard" water, or brackish water) tend to be hard on water heaters due to galvanic corrosion. There are many different kinds of "hard" water, some precipitating on heating, some not. Softening the water keeps sediment from forming, but there is still the problem of all the dissolved salts making an excellent conductor for galvanic corrosion, e.g. between the steel of the water heater and the copper piping, but also between one part of the water heater and another.

The general problems with sediments are that they can make gas fired water heaters much less efficient and by trapping water in pockets under sediment can worsen the effects of galvanic corrosion and the effect of sulfur eating bacteria that produce hydrogen sulfide which leads to local pockets of sulfuric acid. It is less of a problem in electric water heaters, but tends to cause a rapid burn out of the electrode when it gets covered due to overheating, not to mention the loss in hot water storage.

A "glass lined" water heater has had a glaze of glass powder/slurry applied and then melted in place, like the enamel on a washing machine or stove. The enamel is a hard, durable coating. It is hard to make the coating perfect though, so with time the defects in the enamel coating are where corrosion starts and eats through the steel of the water heater tank. If you have ever cut open a leaking water heater, it tends to have an almost perfect enamel coating, with just a place or two where it failed, often on the welded seams. Whether the failure points are a result of a defect of welding, or just a failure point due to dissimilar expansion causing an enamel failure, I have no idea.

Stainless water heaters exist, but they are just stain-less, not corrosion proof, and suffer from an even lower thermal conductivity than steel, which is much lower than copper, or aluminum, which means they tend to be less efficient.

All the best,

Peter

I knew there was a reason that I use a water softener. It must be working for my 26 year old water heater and no sediment that I have found.
I'm thinking about a heat pump water heater when I need to replace this one. It would help to dehumidify my basement.

 

[ponytug]

@lman Congratulations on getting 26 years out of your water heater!
FWIW: My brother has a heat pump water heater set up in his basement to do dehumidify the basement and he likes it a lot.

All the best,

Peter

 

[masscity]

I have a garden hose quick attach and a short hose and I drain a couple a gallons or more every other month into the toilet.

I have very hard water problems. Didn't do the draining before and nothing would come out of the drain. Had to take the full water heater outside and remove the

elements to drain it and clean out the tank. Only a 30 gallon tank.