Print

[MarkP]

I built my own OWB, and I'm really happy with it so far, except:  My biggest problem is having to add water from STEAMING.  Seems that steaming a couple months ago wasn't too bad, and I rarely had to add water, but with the colder weather, and the stove heating more often, the steam never stops.  I saw a post from mid-November that mentioned this same problem on a Shaver, and he suggested extending the vent pipe out further and using a 90* to turn it up a bit and filling a little more water.  My vent is out the top, so that won't work for me.  I DO have an unused fitting on the side that is about 7 inches below the water level that I like to maintain.  If I pipe this out the side of the covering of the stove and 90* it up a few inches, will this work, or will it just push the water out the 90* as it heats??  This one has me stumped, and I'm really tired of adding water every couple days. 

I'm new at this and looking for HELP!!!!   

[R W Ohio]

What are you setting the max temp. of the water in your boiler? And is the temp. going above 190F? It sounds to me that the water is to hot. Also how large is the vent pipe.We use a pvc cap that fits over the vent pipe with a piece of 1/4"copper through it so it can vent but cuts the evap.rate down.If something were to happen though and the need to have the stove push water out the cap could would push off.There are several brands of OWB's that use this kind of setup.I hope this may help.
Ron

[MarkP]

I am using a Honewell Aquastat and have it set to come on at 170 and off at 185.  It had been at 160 - 175 until last week when we were having temps in the negatives.  I have an automotive temperature gauge on the stove, and it is reading @ 195, but I wasn't sure how accurate the temp ga. was.  I had assumed the aquastat would be more accurate.  Maybe a bad assumption on my part.   As for the vent pipe, it is 1/2" steel pipe coming out the top and turning 90*, and exiting the side of the stove just under the roof.  I see where the cap and 1/4" copper might help.  What size vent pipe are you using on yours??  I can increase the size of the steel pipe if I need to to accomodate the cap and copper tubing.  Would it be better if the vent exited straight up instead of out the side??  I'm losing about 4 gallons a day.  I'm open to any and all suggestions.  Your help is really appreciated,,,,,,,, THANKS

[R W Ohio]

The vent on my stove is 1 1/4" and the cap is a 1 1/2" pvc cap. It fits loose enough that it will come off if had water pushing on it, but tight enough to seal the vent pipe pretty well. Perhaps one of the Woodmaster owners could post a picture of a Woodmaster vent system.I think most if not all of them have this type on the water jacket vent.

Ron

[ckbetz]

Mark,

Is your circulation pump running constantly?  If not your heated water may be rising and not circulating back with your cooler water on the bottom to keep your entire storage water at a more constant temp.

[willieG]

i have a home made OWB my fill pipe is an 8 inch pipe on the top of the stove...i put apiece of blue foam over it and then on top of that i added a 1/4 inch plate 8 inch round...so i guess you could say my stove is not open to atmasphere but maybe runs at 1 or two pounds pressure..add water not to often, couple of times a winter

i have seen one model of stove that the vent (and fill tube) was like a long narrow funnel and had what looked like an "indian" rubber ball in it, this the sales guy told me took about 3 pounds pressure to lift the ball to release pressure

[MarkP]

I appreciate everyones help in this.  I am going to try to get a better idea of just what my max temperature really is.  Maybe an infrared temp. gun???  I'm not sure what is available that will be more accurate.  I do alot of work on cars, and find a big variation in temperature gauges for automotive use,,, some as much as 10 - 15 degrees.   Plus, they have to be deep enough into the water to have circulation for accuracy.  I will try turning the temp down first, and see if this reduces the steam.  Has anyone used the temp gauges like the Taylors use?? 

ckbetz:    I have 2 Taco pumps on my OWB.  One for the house, and one for the garage/shop.  I have them both running 24/7.  I thought maybe I didn't have it insulated enough, but it never melts the snow off the roof, except by the vent pipe.   I have a large accumulation of ice under it where it drips.  I am using figerglass insulation,,, 6" under, 12" on the sides, and 18" in the top.  I would be interested to see pics of any vent systems you all might have.  At 4 or 5 gallons a day, plus chemical treatment, this is getting old real fast. 

Ron, is your vent straight out the top of your stove?  I have a 1/2" pipe nipple welded in the top of mine.  Easily adapted to 1 1/4" to use the cap you described. 

Thanks for everyone's input.  I will post results of the things I try.

Mark

[ckbetz]

Yep at 4 or 5 gallons a day something is kinda fishy.  This year I haven't put a drop in my furnace and it works pretty hard.

[R W Ohio]

Mark,
Yes it does come straight out of the roof,next to the chimney pipe.
Ron

[fletcher0780]

Mark,

I'm the one who posted the shaver steaming fix. If I understand your setup correctly you have a overflow pipe at the top of the stove, but an open unused fitting/ port below. How do you limit the maximum water level? Does the water run out that unused port once your finished adding it, or does it come out the vent on the top? The theory behind my steam fix is to limit the surface area of water exposed to atmosphere, I did it by controlling the level by using the 90* upturned which ultimately limited to surface area exposed to atmosphere to the inside area of my 90*.

You need to create a method of limiting your water level, which also keeps outside air from "touching" the top of the water inside your furnace. I doubt your temperature is the issue, water steams long before it boils (like in the shower).

Look at the image below, in the bottom right corner do you see the difference between those two setups? The one on the left allows air to enter through the vent and contact the entire water surface are, the one on the right only allows the water inside the 90* to come in contact with the atmosphere. You might just be able to block the ope port off and fiil the boiler until water comes out the vertical overflow on the top of the boiler.

[MarkP]

The "open" port on the SIDE is CAPPED, just in case I needed it later.  I run my water level about 7 inches above the height of that port.  If I cap the vent on top, and extend the unused side port out and 90* up 7 or 8  inches, can I use it as a vent, or will it just keep pushing the water out until it gets down 7" to the level of that port?  Your lower right picture shows the vent pipe BELOW the water level.  Does it push water out as it heats, or is the level in the 90* with the water at it's hottest??

ALSO..... I just got to thinking, when I first filled it, I filled it to my fill level COLD, and once it got hot, it spilled out 3 or 4 gallons.  So, I am assuming it was totally full at first being fired.  It never steamed for almost 2 months.  I first thought the steam was just the temperature difference between the water in the stove, and the outside air temperature, as the weather started getting colder.  In the past 3 or 4 weeks, I noticed an ice accumulation on the ground under the vent.  That is when I noticed the water level starting to go down rapidly.

I know the fix is probably a simple one, and I'm happy with the stove otherwise.   I have used exactly 3 cords from Oct. 23rd.  to Jan. 23rd. It was oak and hickory mixed, and not seasoned well.  I am heating a 1680 sq. ft. house and 1200 sq. ft. of a garage (both new, and well insulated)   Let me know your ideas, and I will be trying SOMETHING tomorrow.

THANKS!!

[fletcher0780]

If I cap the vent on top, and extend the unused side port out and 90* up 7 or 8  inches, can I use it as a vent, or will it just keep pushing the water out until it gets down 7" to the level of that port?

Yes I think that would work well, the top of your extension will determine your water level.

Your lower right picture shows the vent pipe BELOW the water level.  Does it push water out as it heats, or is the level in the 90* with the water at it's hottest??

It will push water out as it heats and expands, but as long as the temperature stays somewhat constant after that you'll be in good shape. I add, at most, a quart of water every 3-4 weeks, compared to the gallon a day before I modified it

[MyLeakyWoodDoctor]

My Wood Doctor warranty would be void if I altered my furnace in any way, but I can't see how 1 or 2 lbs pressure (as in putting a piece of weighted blue foam on top of the vent) could hurt it in any way!!

What about your warranty, if you have one?

I have another kind of water loss problem - corrosion!   

[MarkP]

I just checked some temperatures with an infra-red heat gun.  I'm not sure how accurate it is, but it seems within a couple degrees on known temperatures.  I checked the  Taco pump, and it was reading 189*, and the side of my water tank near my aquastat well was 192*  My Honeywell aquastat is set to kick off at 185*, and my temp gauge is reading 190*.   Apparently, my temperature gauge is pretty accurate.   All temps are relatively close.  I really don't think I have an overheating situation, but  it might not hurt to lower the temp on my aquastat a little regardless.   It has steamed very little today, as we are having temps around 50.   

I will try a few things tomorrow with the vent pipe.  I will let ya know the results.   Again,,,,,, I appreciate everyone's help.

Mark

[willieG]

mark..just to let you know the difference in "cold" and "hot" temp of your stove, your water when hot, will change the water displacemnet about 10 percent..so lets say your stove and pipes hold 150 gallons cold..when hot that will grow to 165 gallons and water taking up about 7.5 gallons per cubic foot, you would need about 2 cubic feet to hold the "extra" water when hot ...now once hot it will not "shrink" that 10 percent because you will not be cooling down to the temps you filled it at

i have  an 8 inch pipe about 10 inches high for my "buffer zone" i  fill it at the high temp and when it is at the low temp it is down about 6 inches  remember the shrinkidge will not be as severe as when you filled the stove the first time because it is only cooling 15 or 20 degrees not from  the tap temp to the high temp (that is most likley around 120 degrees)

hope some of this makes sense