could this cause a rise in power consption?

Yes, you should be running straight cold water ONLY through the RO membrane !!!

Never ever try to blend or temper the hot and cold. Remeber being in the shower and someone flushes the toilet or starts the washing machine? You got scalded. Same thing happens to the membarne and it melts at 113 degrees, thats lower than some hot tubs.

Always use cold water only in an RO or RO/DI. Not only is it safer for the membrane, it also treats better due to the increased viscosity which means lower TDS from the RO only and longer DI life. If the cold water cuts down the GPD drastically a booster pump is a good option as membranes love pressure which not only makes up for the colder water but again makes the membrane work better for lower TDS.

 

Cold water is all I use. And I a making water while we sleep, so there is no toilet flushing. Because I was unfamiliar with apartment plumbing, I wasnt sure if the cold water was running through the water heater causing the power consumption rise. But it doesnt look like that is the problem why the my bill went up

 

You might look at your power bill, we have different rates according to the months and the demands here in Phoenix.

 

Someone else hinted at this, but didn't quite explain it as I would have. It is possible your meter was mis-read last month. This could make your bill exceptionally high. However, when they read your meter this month, they'll read it correctly, which will effectively catch their error from last month. If your bill is much less for this coming month, this is likely what happened.

 

This is true, unless your meter is digital, which transmits by radio, and cuts out the "human factor." Power Companies around the country are slowly integrating this into older areas.

 

Hell, I live outside of chicago in a newer area, Comonwealth Edison hasn't even started to convert around here.