RO filtered water in boiler

[Deleted User]

Is there a problem in filling a boiler and radiant system with water from a reverse osmosis filter? Does the water become too aggressive?

Kyle Kubs - Benchmark Home Inspections

RO water is mildly acidic

RO water is just a bit on the acid side of the ph scale and typically can't be fed through copper pipes because it eats away at the copper. However in a boiler where you should be using the same water all the time I would think it would tend to neutralize. My question is why would you want to do this? A normal RO would take a week or more to fill a normal system. If your worried about lime and scale I'm sure there are better way's to take care of that, however for that answer I will bow out for one of these guy's that makes me look like a rank amatuer...

[Deleted User]

capacity

The system is designed for 100 GPD for other reasons so it is only a couple of days output. The idea was to keep all of the gunge out of the initial system fill. It is well water and has a number of strange things in it.

gerry gill

I'd ask the

boiler manufacturer and the tubing manufacturer...my gut says no...how about bottled water?

kevin_22

Wells

Harold
I do a lot of systems on well water. I have a 200 gallon tank that fits in the back of my pickup(F350). I make the initial fill with water from my home(city water). The bonus is I use the tank as a purge tank and circulate the water back thru it. Even on wells with good quality water their could be a lot of entrained air in the water. Which is a real pain with a Vitodens heat exchanger, on the vitodens I usually fill the tank and let it sit for a night to allow some of the entrained air to perk out.

[Deleted User]

Gut

My gut feeling is also that even if it is agressive water because it is demineralized, it will reach equilibrium in a closed system before any damage occurs.

I need more than 200 gals of water for the system (85 gal buffer tank alone) so buying the water at Walgreens is not real practical. The choice is RO output or water with assorted minerals and a ph of about 8.2. It probably does not matter. But I would just like to know and do it right.