Water Bill Shock

[stubbsz]

So I got a huge water bill this month. At first thought it was my efforts to green up my front lawns. I just got back to the house after an hour away and noted that I could still hear the waste running on the RO unit. I changed pre-filters the other day and wondered what I might have done to upset it. I took a gallon of top up water out at around nine and at 10:15, its still wasting water although the tank seems like it's pretty full.

Any reasons that you can think of that this would be happening?

-Adrian

 

[Anonymous]

Is the automatic shut off valve working? When the pressure on the output is higher than a certain point, it should shut off automatically.

Or you may want to manually turn the unit off. That way, you will know exactly how much water was used. Depends on the GPD rating on it, say that it is 50 gal per day, then with rejection ratio of 4:1, it uses 5 gal of water per gallon of RO. If it malfunction, and run 24/7, then it will use 250 gal of water per day. Per month, it will use 7500 gals.

 

[stubbsz]

Thanks.

I used 200 gallons per day more than I did last year for the same month. I have the unit it for 8 years...maybe time for a complete new unit. This was a cheap Costco thing, any advantages with particular manufacturers or anything else I should consider if I replace this one. In the mean time, I'll measure the rejection rate and see if there really is something wrong

-Adrian

 

[Anonymous]

Costco use Premier brand, and it is pretty good. Depends on your setup, I will say check the shut off valve to make sure it is not running 24/7.

I put my RO/DI on a timer with solenoid valve, so there is no way it is running any more than a few hours per day.

 

[Anonymous]

Yeah, 200g per day is a lot of water, more so when it's 200 MORE gallons per day. I have noticed that occasionally the waste water will keep going, and I haven't figured out the reasoning behind it, I notice in the warmer weather this wouldn't happen, but if it gets too bad just turn it off at the source (which sometimes is a pain if its under your sink).

 

[Anonymous]

I have noticed that occasionally the waste water will keep going, and I haven't figured out the reasoning behind it, I notice in the warmer weather this wouldn't happen, but if it gets too bad just turn it off at the source (which sometimes is a pain if its under your sink).

This happens when you're not warming up your RO source water. Cold water is not as viscous and will not penetrate the RO membrane well. As a result, the pressure on the "filtered" side of the RO membrane will often not be sufficient to turn off a pressure sensitive valve. If you're using an electronic shutoff then this doesn't apply.

A simple way to fix the cold water problem is to submerge a few loops of tubing in your sump to warm the source water before it gets to the RO membrane. The RO will work better this way regardless of the typs of shutoff valve.

 

[Anonymous]

Ahhhh. See now while I did have a feeling this was the case, this is not something that is mentioned on my RO unit! It would be nice though so as I dont waste a buttload of water. Problem is my RO unit is under my kitchen sink and my tank is in another room (lucky I'm not married as my wife would not appreciate a bunch of 1/4" tubing running through the hallway), so running the original line to the sump might be problematic, but you can get vinyl tubing at lowes for a few bucks for a couple hundred feet, so who knows.

But thanks for the heads up on the viscosity.

 

[Unresistible Blue]

This happens when you're not warming up your RO source water. Cold water is not as viscous and will not penetrate the RO membrane well.

Hmm... water becomes more viscous as it gets colder...

Trouble with ASO valves can often be traced back to a leaking float valve, or a bad check valve between the permeate port and the low pressure in port on the ASO valve.

Because this happenned after you changed out filers, I suspect you have trapped air in the ASO that is causing trouble.

If this problem hasn't fixed itself, let me know and there are a few fixes you can try.

 

[Anonymous]

Right... Lower viscosity as it is warmed up and therefore the warmer the easier it will flow through the membrane. Sorry for the typo.

Warm up your water so it will flow through the membrane easier.

 

[Anonymous]

Just a comment.

If you want to warm up the tap water, keep in mind that it should be done for "free." The amount of electricity it take to heat up may cost more than the saving in water. Some use long run of tubing in the sump to "preheat" the water (and chill the tank water slightly) if the tank water is usually too hot and chiller is used most of the time.

 

[Anonymous]

8O

I just installed a RO/DI unit under our sink. After it filled the storage tank I checked the drain tube and nothing was coming out. I need to check again today. I have nightmares about this since our water bill in my area of MA is insane.