Rust or Sediment Stains and Hydronic Water Tank Draining
#1
06-10-20, 12:34 PM
Rust or Sediment Stains and Hydronic Water Tank Draining
I was away from home for a few months this spring. When I returned a hose bib was leaking and these stains were present on the stamped concrete. Thinking it was sediment from my well, I used a 3100psi pressure washer, but it couldn't remove the stain as you can see in the photo. Even though this is obviously a cold water line, I then began to think it's a rust stain, but I have no idea what would have caused the rust. Any ideas>
Secondly, I read the sticky post warning not to periodically drain a hydronic water tank, but my Viessmann CVA450 tank manual recommends draining and inspection of the tank and anode every two years. So, what is the recommendation for this tank? The closest Viessmann certified tech is a $450 trip charge away, so I don't want to have the tank serviced unless it's really necessary.
Thanks.
Secondly, I read the sticky post warning not to periodically drain a hydronic water tank, but my Viessmann CVA450 tank manual recommends draining and inspection of the tank and anode every two years. So, what is the recommendation for this tank? The closest Viessmann certified tech is a $450 trip charge away, so I don't want to have the tank serviced unless it's really necessary.
Thanks.
#3
06-10-20, 01:02 PM
No problem draining this hydronic storage tank other than consuming time and water.
Usually draining between two and 5 gallons of water every 6 mongths should keep it clean. Every other time do the draining with the cold water supply turned off and an upstairs hot faucet open. Check the anode on the times when u drained it this way with the supply water turned off.
oy
There is a separate procedure for flushing the heat exchanger coil that connects to the boiler next to or near the tank. This is comparable to servicing a tankless water heater.
Usually draining between two and 5 gallons of water every 6 mongths should keep it clean. Every other time do the draining with the cold water supply turned off and an upstairs hot faucet open. Check the anode on the times when u drained it this way with the supply water turned off.
oy
There is a separate procedure for flushing the heat exchanger coil that connects to the boiler next to or near the tank. This is comparable to servicing a tankless water heater.
#4
06-10-20, 01:10 PM
The first post, Marq1, was in a concrete forum not plumbing and requested stain removal advice, not rust causation. Further, the first post didn't address tank draining, so the difference is obvious. I ordered a gallon of GoofOff rust remover and will try that on the stain. If you can help me understand how a dripping faucet generates rust, I'd appreciate it.
#6
06-10-20, 01:46 PM
Member
If you can help me understand how a dripping faucet generates rust, I'd appreciate it.
#7
06-10-20, 03:07 PM
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zich -
(just saw Marq1 post - but since I went through the trouble of typing all of that below ...lol)
If your well has a lot of iron then wouldn’t the iron rich water dripping on your concrete, and then exposed to oxygen, eventually rust? It seems like it would to me – but I’m no expert.
(just saw Marq1 post - but since I went through the trouble of typing all of that below ...lol)
If your well has a lot of iron then wouldn’t the iron rich water dripping on your concrete, and then exposed to oxygen, eventually rust? It seems like it would to me – but I’m no expert.
#8
06-10-20, 03:49 PM
I've had my water tested recently and it isn't hard and doesn't contain above normal ppm of iron. More likely after talking to my well driller is a galvanized pipe that has lost it's galvanization after being exposed to air during my two month absence.
So, any ideas on the 2nd part of my post that didn't appear in the concrete section. Marq1?
So, any ideas on the 2nd part of my post that didn't appear in the concrete section. Marq1?
#9
06-10-20, 05:38 PM
Member
So, what is the recommendation for this tank?
#10
06-11-20, 10:10 AM
I was away from home for a few months this spring. When I returned a hose bib was leaking and these stains were present on the stamped concrete.
Secondly, I read the sticky post warning not to periodically drain a hydronic water tank, but my Viessmann CVA450 tank manual recommends draining and inspection of the tank and anode every two years.
#11
06-11-20, 01:40 PM
I haven't had good luck with CLR on other rust stains, so I ordered a gallon of the highly rated GoofOff rust stain remover. I'll post how it went. I was gone for 81 days and the faucet was dripping at least two drops a second, so that could be a lot of water. About 144 square ft. were stained and wet when I returned. We also had high winds as you can see from the wall stains on the left side of the faucet.
The Viessmann 119 gal. water storage tank has a heat exchanger fed by a Slantfin boiler. The factory rep called and gave me the procedure to check the anode for corrosion which I'll do soon. Upon further inspect the manual requires inspection every two years and only draining "if necessary." So, I don't plan to drain unless there are anode problems.
The Viessmann 119 gal. water storage tank has a heat exchanger fed by a Slantfin boiler. The factory rep called and gave me the procedure to check the anode for corrosion which I'll do soon. Upon further inspect the manual requires inspection every two years and only draining "if necessary." So, I don't plan to drain unless there are anode problems.
#12
06-11-20, 03:42 PM
You got the rust stain on the concrete because the faucet dripped on the same spot day after day, month after month, and the water evaporated leaving the mineral content behind on the concrete. Included in the mineral content was a minute amount of dissolved rust from water mains, house plumbing, etc. No additional rusting or corrosion took place in the water after it left the faucet.
you.