Accident! Hot water through RO unit

calbert0

Member
I always run cold water through my R/O unit, but the other day i was short on water so i adjusted my sink temp to run room temp water through my R/O unit.
After making up about 5 gallons i turned off the cold water feed like normal and went to sleep (completely forgetting about the hot water knob)
When i woke up in the morning i realized that i had been running super hot water through my RO unit all night!!
Did this likely damage my filters?
 

florida joe

Well-Known Member
I hate to tell you this but everything i have ever read about RO installation states never to allow hot water through the unit as it will destroy the membrane
 

davmul

Member
Been there and done that..... I had the hot water on for about 20 minutes but I did notice that I had detectable phosphates in my freshly filtered water. Try filtering some more water and test. Make sure you test straight from the filter output. I kept using mine for several months with no ill effects, but it always bugged me. When I needed new filters I also picked up a new membrane. It will run you $40-$45.
 

reefkprz

Active Member
IMO the membrane is probably fine check TDS to determine whether or not to replace.
the reason for not using hot water on an RO unit is to keep the pores of the membrane closed, a recomended water temp for an RO unit to operate at full efficiency is 70° to 77°F at which the membrane through temperature expansion will be the correct size to allow maximum flow through rate without letting excess pollutants through, colder water makes the membrane tighter making for more discharge, hotter water allows more pollutants through. a unit operating at 70°F that has 2 TDS may allow somewhere near 14+ TDS at 90°F (numbers are not exact check you unit for actual specs)
.
 
I recently had the same thing happen to me. I accidently had 100 degree water going through it. I was getting 15 TDS. After I ran cold water back through it I was back to 1-2 TDS.
You'll probably be fine. Just check the TDS to see if you need to replace the membrane.
 

florida joe

Well-Known Member
Some more thinking on the subject of hot water. I would think that our ro unite membrane is not made to handle hot water. There would have to be given that logic a point of degrading of the material the membrane is made of at a certain temp. also there would be more fouling of the membrane with hot water as the water supplied from a hot water heater has more TDS in it then cold tap water (how many of us flush our Hot water heaters regularly)
 

cranberry

Active Member
I don't know the particulars... all I know is when I got my first unit I connected to the hot water. O.O Didn't know at the time you weren't suppose to. One day I noticed a big aneurysm in the plastic line and thought "Hmmmm, that can't be right". O.O O.O It was like that for awhile. When I flipped it all around and flushed the membrane, I still had zero TDS.
 

pezenfuego

Active Member
Originally Posted by florida joe
http:///forum/post/3245837
Some more thinking on the subject of hot water. I would think that our ro unite membrane is not made to handle hot water. There would have to be given that logic a point of degrading of the material the membrane is made of at a certain temp. also there would be more fouling of the membrane with hot water as the water supplied from a hot water heater has more TDS in it then cold tap water (how many of us flush our Hot water heaters regularly)
Hot water heater? If we have hot water, why would we heat it? You make absolutely no sense sometimes Joe
 

florida joe

Well-Known Member
Originally Posted by PEZenfuego
http:///forum/post/3245983
Hot water heater? If we have hot water, why would we heat it? You make absolutely no sense sometimes Joe

kind of like jumbo shrimp I guess

Or perhaps I do make sense. My young friend need I really explain. Guess I do. You have Demand (tankless or instantaneous) water heaters which provide hot water only as it is needed. Then you have storage water heaters which bring your stored water up to temp and store it (hum hence the name) now when the water falls below a certain temp the hot water is reheated to the upper temperature you set it at. This unit is called a HOT WATER HEATER
 

pezenfuego

Active Member
Originally Posted by florida joe
http:///forum/post/3246006
kind of like jumbo shrimp I guess

Or perhaps I do make sense. My young friend need I really explain. Guess I do. You have Demand (tankless or instantaneous) water heaters which provide hot water only as it is needed. Then you have storage water heaters which bring your stored water up to temp and store it (hum hence the name) now when the water falls below a certain temp the hot water is reheated to the upper temperature you set it at. This unit is called a HOT WATER HEATER
I was only joking with you...
Didn't mean to get

As long as you have a tlc membrane, I don't think the hot water will destroy it.
 

srfisher17

Active Member
Just a guess. I'd think that, because RO equipment can be used for human consumption and are plumbed in a household system---they would have to handle hot water.
BTW, where Joe lives, the temp of the cold tap in Aug is probably higher than my hot water setting. (Which would really hinder his needed "cold" showers!
)
 

florida joe

Well-Known Member
Originally Posted by srfisher17
http:///forum/post/3246028
Just a guess. I'd think that, because RO equipment can be used for human consumption and are plumbed in a household system---they would have to handle hot water.
BTW, where Joe lives, the temp of the cold tap in Aug is probably higher than my hot water setting. (Which would really hinder his needed "cold" showers!
)
I don’t know of many or any for that matter ro units piped into the hot water supply just not practical. You would need a very large holding tank for hot water applications as well as the large amount of waste water produced
I believe we need to consider the flux rate as it applies to the membrane. The flux rate decrease with the membrane compaction. The rate of compaction with increased temperature causes more pressure on the membrane and thus braking it down.
FYI I keep ice packs for when I can not take cool down showers
 
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