HELP! OWB question

[OUBrew]

I bought an OWB from a guy that owns his own steel business. He created his own design and produces them himself. I talked to several of his customers and they were satisfied. The stove was very well priced compared to the others I was looking at...

I am heading into my third heating season with it. I have had several problems with it but my main concern is I just cannot heat my house with it when the temps drop below zero. Now I have a large house with an open design (16' sidewalls and 32' peak) My heating system is all in floor radiant. 3 zones, one for each floor. The in-floor system is not designed properly but it keeps my house at 70 in 0-10 weather with my LP boiler.

When I run both the main floor zone and the basement zone I have a hard time keeping the incoming water temp at 140 degrees...heading into the exchanger (I have a plate exchanger from the OWB to my Polaris Boiler) The water going into the floor has been 110 deg. I would like it at 140 deg heading into the floors and 170 coming into the house. Cannot reach this with the OWB with both zones running together.

Here is what is interesting to me...I often have water boiling out of the fill stack on the OWB. I had a problem with my aquastat last year...it would run all the time and not heat the water up to the set temp. I found I could just use the air from the warped door (not good I know) as a natural draft and the stove seemed to operate better. I had to add water almost every day to the stove...which doesn't seem right to me. It was a lot of water...most of it lost to steam. The tank is a cylinder design around a round firebox. Both supply lines are at the top of the cylinder and the returns are at the bottom.

Basically...this not much better than me putting together my own system if I knew how to weld. Anything else you experienced readers need to know. Any helpful ideas would be appreciated!

Thanks

 

[applefarmer]

What did you use for underground pipe? Can you check the heat loss between the boiler and the house? If so what is it?

 

[blackdogon57]

If your water is really boiling off it should be leaving the boiler to the house at close to 200F. If it is 140 or less when it gets to the exchanger you have a problem with your underground lines. If you used thermopex or similar material you should have almost no measurable heat loss underground.

 

[showrguy]

after about 6 years i noticed i was adding more water than before..
i thought i had a leak so i pressure checked the OWB and it was fine..
on my vent i took a clear plastic bottle and poked a bunch of small holes in it so the steam cools in the bottle, condensates, then runs back into the unit, all while still being able to "vent"...

i also have some very tall open spaces in my layout, all radiant in floor...
the only time i have issues is when it's very cold and very windy..
windows radiate alot of cold when it's windy...
i run into the house @ 180-190, to a 125 gal nurse tank set @ 140 to all my zones...

 

[1harlowr]

Sounds like either water getting to you underground lines or the OWB doesn't have a high enough water capacity

 

[OUBrew]

Thanks

I have checked the heat loss from the water leaving the boiler to the temp gauge right as it enters the house and it has always been around 2 degree loss. I have a temp gauge on the front of the stove about 3/4 of the way up the cylinder and even when it boils over...it never reads over 180 deg??? How can I have that temp differential in that small of a distance and that little of water? It's like the water on the bottom of the jacket is signficantly coller than the water on the top of the jacket. I can understand the water on the bottom being cooler because of the return lines located there but I don't get 80 degree difference? I am losing so much energy up at the top I would like to send to the house.

 

[showrguy]

does your unit have an internal circulator ??
(a pump that continuenly circulates the water in the water jacket)

if not, i'd be looking to install one, taco 007..
my .02 cents

 

[Windwalker7]

Air trapped in line somewhere?


Flat plate exchanger corroded inside not allowing heat transfer?

Has it always been like that or did it just start?

 

[OUBrew]

Showr

Is there a special pump I could look at for moving that water around in there? Are you saying to just have a port supply port leading to the pump and directly back into the jacket? That makes sense.

How can I check if there is air in the line?

 

[OUBrew]

Wind

It may be an issue with the exchanger...but it has been hotter on the supply line than the return line and it is heating the water into the boiler.

Your air question is interesting because I have no release point in the lines???

 

[Laird]

I have checked the heat loss from the water leaving the boiler to the temp gauge right as it enters the house and it has always been around 2 degree loss. I have a temp gauge on the front of the stove about 3/4 of the way up the cylinder and even when it boils over...it never reads over 180 deg??? How can I have that temp differential in that small of a distance and that little of water? It's like the water on the bottom of the jacket is signficantly coller than the water on the top of the jacket. I can understand the water on the bottom being cooler because of the return lines located there but I don't get 80 degree difference? I am losing so much energy up at the top I would like to send to the house.

I am also curious how many gallons the OWB holds. It's possible that it is not actually "boiling" if it usually overflows shortly after you add water to it. The water heats up and expands and overflows for awhile. If your water tank is too small for the size of your house it cannot store enough heat to keep up with the cold water returning to it. Is your draft fan driven or just natural draft? If it is just natural draft this would aggravate the problem if your tank was too small. A fan driven draft gets the fire hot fast and can help compensate for firewood that might still be slightly wet.

 

[showrguy]

Is there a special pump I could look at for moving that water around in there? Are you saying to just have a port supply port leading to the pump and directly back into the jacket? That makes sense.

How can I check if there is air in the line?

mine uses a taco 007, pumps from bottom to top 24/7..
if you dont have the ports they would be easy enough to install for a steel fab. guy to do.... but you'd likely need to drain your unit...

Laird has a good point also.....

 

[OUBrew]

Laird

The OWB jacket is 165 gallons. I just talked to the guy who made the stove and he told me the stove is too small to heat my entire house. Would have been nice to know that when I bought it...on me I guess.

The aquastat would never shut the forced air off show I have been just using natural draft through the cracks in the warped door. You're saying this could be making my problem worse?

I lose more to steam than to boil off but I add a lot of water!

 

[Windwalker7]

I am not sure of how you are set up but I have a ball valve on my return line right before it goes back into OWB.

While the pump is running, I close the valve for about 4 seconds and then open back up. I repeat this about 3 or 4 times. Sometime you can hear the air bubbles going through and into the boiler.

 

[Windwalker7]

How is your vent tube situated on your boiler?

Is it a horizontal pipe near the top of the water jacket like on a Shaver OWB?

 

[OUBrew]

No it's a vertical 3" pipe off the top of the water jacket

 

[Windwalker7]

I am wondering if it is too big allowing too much steam out.

If you could maybe restrict it somehow but still allow air to escape it might help.

Maybe do as someone else suggested, They put a plastic bottle with holes in it. Enough to allow air out yet water condenses and runs back into boiler.

I'd try closing the ball valve a few times to get air out of the lines if you are set up to do so.

I know it is frustrating, Sooner or later you are bond to find a way to improve on it.

 

[OUBrew]

I will! Much thanks to you all!

 

[Windwalker7]

A thought just occurred to me. You mentioned having boil overs.


I'm sure we have all seen water boil in a pot on the stove. We see all the bubbles going everywhere.

I was thinking that if you've had boil overs, I wonder if you pump didn't suck up some of the boiling water (air bubbles) and put air in your line.

 

[boilerwood]

You say your supply lines are at the top and returns on the bottom? Mine are just the opposite. Could it be that your water level got below the supply feed and allowed air in to the system? You might check with the maker, maybe it should be supply on the bottom and return on the top.