make up water on a typical owb

Since adding a 300 Gallon storage tank to my system and tying the two together. I add 18 litres per week.

I did this by taking an 2 1/2 inch diameter pipe that extends 3 feet above the closed storage tank .

This pipe runs to the open expansion tank on the top of the OWB and dumps the expanded flow into the top of the OWB .

I can see the continuous steam rising out of the OWB, where before adding the storage I did not see the steam exiting thru the closed lid.

This steam translates to 18 litres as I add approx that much every Saturday wehter it needs it or not.

I have no leaks anywhere so it is all evaporation.

That doesn't sound right. What brand do you have? I have a Hardy and added about 5 gal. a week. It is less now, but still adding some water weekly.

That much loss sounds like there is some sort of issue, though I'm not sure just what... I certainly would be double checking for leaks, followed by looking at whether everything is set right on the controls (i.e. you aren't trying to BOIL the water in the boiler...) that nothing is getting over-filled, etc...

As a point of comparison, I seem to recall that most of our Garn users seem to have been talking about needing makeup water on the order of a few gallons per YEAR, and that's with a lot more water in their systems...

If nothing else, if I was adding that much water on a regular basis, and losing it through evaporation, I'd be worried about the accumulation of mineral deposits in the system - remember evaporation gets rid of the water, but the minerals and dissolved solids stay behind...

Gooserider

18 liters or 5 gallons a week is too much.
Evaporative loss is wasting a fair bit of wood and in the case of these boilers, as Goose mentioned,
you will slowly be building up mineral deposits somewhere that you don't want them-usually the hottest
part of the heat exchanger.

I would go over the unit and try to seal anyplace that is showing "steam" or water vapor.

We use neutral cure silicone caulk to seal our tanks. This is also known as low odor silicone caulk.
It does not smelly vinegar-y like regular silicone caulk.
Neutral cure bonds much better. This might be an issue if you need to get into the unit.
In our case, we can break the bond and re-seal if necessary.

In my case the water usage seems to have appeared since I added the storage expansion dump.

As I am dumping it into the once closed lid and the lid nows remains open to allow the expansion pipe to recycle the water.

I have a spin on coolant filter in my system that should catch any contaminants as I also treat with rust inhibitors.

Water smells and looks clean.

Reminds me I should try add water today see how much it takes

Well it took 18 litres as predicted.

Here is a picture of the open lid original expasion tank

plumbob said:

, but ranges from 160-190.

Click to expand...

This is probably why you are "using" so much water. As the water heats it expands it is going out the top, as it cools back down it looks like less water. Instead of adding water weekly, note the water level and temperature as this will make more sense. Adding that much water to the system will dilute your water treatment very quickly.

I added about a gallon at the end of last year after the 1st full year of running my open system. It isn't filled to the top during operation because the water temperature changes, expands and some spills out.

Tim

my OPB has a plastic cap on the boiler vent, I notice a small trickle of water coming off it when it is cold enough out to freeze it, but don't normally have to add water much during the season, I think the cap causes some to condense and fall back into the boiler, you may want a loose fitting cap to help condense the steam and return it to the tank. (much like why you want to run a crock pot with the lid on it)
another idea, are you getting cavitation in a pump? that steam created by cavitation may be causing bubbles of water vapor that exit the boiler vent.

My water level kept dropping on my owb for the first couple of days. But I could hear water in the tank bubbling so I figured air is still being purged from the pex lines and as the air bleeds off the water level drops in the tank. After 3 days the level seems to have stabilized.

My OWB owner's manual says you should only have to add water once a year.

I have lost zero water in my E-2300 been running for about 2 months now

Paso said:

In my case the water usage seems to have appeared since I added the storage expansion dump.

As I am dumping it into the once closed lid and the lid nows remains open to allow the expansion pipe to recycle the water.

I have a spin on coolant filter in my system that should catch any contaminants as I also treat with rust inhibitors.

Water smells and looks clean.

Reminds me I should try add water today see how much it takes

Well it took 18 litres as predicted.

Here is a picture of the open lid original expasion tank

Click to expand...

That is seriously bad... It is likely to cause issues from condensation on everything else in your boiler room, as that is a LOT of water... While filtering the fluid isn't a bad idea, it isn't going to do much for dissolved minerals as they will flow right through any filter along with the water, until they get to a place where they can "plate out" and build up deposits - the minerals seem to be especially fond of tight passages like heat exchangers. You can also have problematic levels without reaching to point where they are visible to human senses...

What I would probably try to do with that setup is get an upside down domed lid, say like a garbage can, or maybe a junked top from a Weber "flying saucer" BBQ grille and cut out a notch just big enough for that pipe... This would give the water that is currently escaping as steam a chance to condense and drip back down into the tank... Either that or notch the edge of the tank so that you can recess the pipe and close the lid on top of it...

Gooserider