Aqua Stat Problem?

[OUBrew]

I bought a OWB from a local guy who runs a steel shop. He came up with his own design based on AquaTherm. Anyway....its an open design non pressurized so I have to add water frequently from steam loss. Also, the aqua-stat never seemed to work last year. I had it set from 160-180 and it would never shut off. The blower was running all the time. Finally, I just ended the season turning the blower off and leaving the stove door cracked. I never had any trouble with logs falling and opening the door and the stove ran cooler but it was more consistent. I had the guy I bought it from come out this summer and check it out and he gave me some explanation about the water at the top of the tank staying hotter than the bottom because both of my return runs are at the bottom. Should this cause the stove to run this poorly or do I have a bad aqua-stat?

Also...could a guy hire a plumber to cap the steam vent/water access and pressurize the system with no danger? I hate having to fill it with water everday.

Maybe its just a poor stove?

 

[AIM]

I would not by any means turn the system into a pressurized system. That could be very dangerous. Pressurized systems are designed and built quite a bit different.

I'm guessing that your aquastat is bad like you suspect.

Go get a new aquastat and turn it down to 140° and see what happens.
Your stat should turn off pretty regularly through out the day.

 

[OUBrew]

Is there a difference in aqua stats? Is there one that is best for OWB's?

 

[dean06919]

Are you sure you don't have a leak anyplace? I filled my stove from inside my house once a month and never have to have the valve on more than 20 seconds before water starts to run out of the vent.

Do you have a H2O temperature gauge built into the stove or on the feed line? I am just curious what your water temperature is. Could it be possible that your aquastat is allowing for your H20 to get over 215 degrees which would cause it to turn to steam?

 

[bowtechmadman]

I add water once every month or two...open valve for 20-30 secs only or I'm overfilling. Might have two issues going on...You'll know doubt be boiling water if your blower never shuts down...this should be controlled by temp from your aqua therm. What kind of temps is it showing? Where is the temp probe located?
I'd double check for leaks b/c if your having to refill daily that would be a lot of water boiling.

 

[OUBrew]

The fill pipe is usually steaming. It is a 3 inch pipe and I have a softball sitting on the top of it. I filled it this morning and I let the water run for a good 10 minutes. If I fill it up to the top it will boil over and I have water all over the floor. I do not have any leaks I am aware of unless they are underground in the pex?

The aquastat well is located at the top of the cylinder on the front. The temps are only reading about 140-150 degrees on the water tank temp gauge and it will steam

 

[OUBrew]

Actually...I looked closely at the design and the aquastat well is about 2/3 of the way up the cylinder. There is a lot of water above it so the water temp could actually be much higher above where the temp is being read? It is steaming all the time so I would assume that means the water is close to boiling temps?

 

[bowtechmadman]

I'm at a loss OUbrew...if the water is only showing that it's at 140-150 then obviously shouldn't be boiling. I think I'd be talking to the manufacturer or a local manufacturer rep. Definately questioning the aqua stat or where it's getting it's temps from.
Here is a link for another forum that may be able to provide some help for you.
http://**********/

 

[fletcher0780]

water need not boil to steam (think shower). I have a Shaver boiler and had lots of problems loosing water because of steam until I discovered a simple solution. The trick is to limit the surface area of hot water to the atmosphere. My shaver had the vent pipe exiting the boiler horizontally, so the entire surface of the water was exposed to the atmosphere and created a lot of steam. I added a 90* to the vent pipe and filled the boiler until the 90* filled with water. This now protected the water inside the boiler from steaming into the atmosphere, and only allowed the water in the 90* (less than 1 in.sq.) to be exposed and steam. I used to ad water almost daily before the modification, now I might add water once every two months.

I'm not sure how large your vent is, or how its configured, but you need to try and limit the amount of water surface area "touched" by outside air. Maybe fashion a "p" trap on top and add a bit of antifreeze to sit in the trap and protect the steaming surface, or simply slide smaller vent pipe inside your existing one down further into the water? Don't pressurize the boiler, just be creative in reducing the surface area exposed to atmosphere.