New to OWB

[azmtnman]

   My son-in-law and daughter just gave us their old Canadian Cold Killer OWB. It's old. My son-in-law is a professional motorcycle mechanic, so he's very handy. He bought this one and fixed the leaks. It still had some leaks so he used Black Swan Powered Boiler Stop-Leak in it. 
   I hauled it 1600 miles and have begun installation. After I set it in place, I filled it up. It leaked. However, after I built a fire in it and heated it up to test operation, it quit leaking even after it cooled down. I'm ordering some more Black Swan for backup.
    When we bought our house, (took total renovation) I had a coil put in our new ductwork, so all that is there. I have the material to make my own boiler tubing (drain pipe, 1" pex and insulation.) The OWB sets about 70' from the house and about that far from the workshop that is currently under construction in the other direction. I am burying a half barrel about 8' from the boiler for junctioning later and for my fill valve.
    FYI, I did commercial HVAC/R for 20 years. 
     I'm wanting your recommendations on this:
     We have wide temperature swings within a 24 hour period--typically 40-50+ degrees. So, we'll have 30's at night but 70-80 during the day this time of the year. If I leave the pump on, it will excessively heat up the house by natural convection. Should I just put an outdoor thermostat on the pump or should I control it another way? 
    Also, water treatment and testing? What do you recommend? I worked on boilers some but I never had to maintain the water quality.

[beenthere]

With your boiler experience, then you likely know that you need to immediately heat any fresh water you add to your boiler system to drive off the oxygen, or you will get a lot of boiler rusting. 

I'd wonder how your water pumps will handle the stop-leak you have added. Don't know, but you may find out. 

[thecfarm]

I have never tested my water for the OWB.
But the wife use to have a cooking license and we had the water tested for that. This test is beyond a home owner test.
Did it each year for 3-4 years and water passed with flying colors.
I feel depends on your water.
Classic seems to push the additive to the water.

[doc henderson]

It sounds like you need a valve and control to let the boiler and underground line continue to circulate, but only open to the house heat when it is called for.  We have an inside boiler, so no outdoor lines to freeze.  We have a concrete floor with pex, so if it warms outside, the circulation in the floor can shut off, but there is lots of heat still in the floor.  So, we can overheat especially spring and fall.  cold at night, but warm during the day.  we also have some passive solar.  We like it cool at night, so we set the thermostat to a cooler temp, and use the woodstove during the day if needed.  It is a trilevel and the upstairs is forced air with a heat exchanger in the air handler.  I know you are a pro., but do you have one of those friends that is the local boiler heat guru.  Our local high end HVAC company has two guys that do all the design work on these systems.

[gspren]

I had 2 seperate buildings heated by my OWB and the 2 were very different. The house circ pump ran all the time and heated the water in the oil boiler, not what you want. In my other building I had the pump inside the building and wired to a thermostat while the water went through a cast iron radiator, when the building called for heat the pump came on and shut down when the thermostat was satisfied.

[barbender]

I have a main circulating loop that comes into the house. The pump is on the OWB. This one runs continuously. Then inside the house I have 2 loops that pull off the main loop. They each have their own pump and thermostat. These pumps only come on when the thermostat calls for heat.

[PoginyHill]

I have never tested my water for the OWB.
But the wife use to have a cooking license and we had the water tested for that. This test is beyond a home owner test.
Did it each year for 3-4 years and water passed with flying colors.
I feel depends on your water.
Classic seems to push the additive to the water.

I'm confused, cfarm. Are you talking about domestic water testing, like for bacteria, minerals, and metals? Water used in a boiler is normally tested for pH. A slightly basic pH is best to reduce corrosion. 7.0 is neutal. A pH of 8-10 is best to minimize corrosion. Pressurized homeowner boilers are not normally tested, because they have no oxygen available. OWBs are not pressurized and are open to the atmosphere, so oxygen is more of a concern. And it is oxygen that facilitates corrosion - just less so in a basic water environment. Industrial boilers use oxygen scavengers to eliminate oxygen in addition to maintaining a basic pH.

[azmtnman]

I have a pH monitor that I have used for checking my soil. I was concerned about minerals in our water. It isn't too bad, but I know it has some. Our water comes out of the well about 7.2pH.

[rusticretreater]

I bought some pH test strips but also some molybdate test strips.

As noted, you want pH neutral water.  How you get that is up to you.  I have a great water filtration system for my well water.  But in addition to that, I add a product called Moly Armor to the system.  This is a corrosion inhibitor.  The molybdate test strips will tell you the ppm of moly armor in the system so you get the correct amount.

I had bought an old Woodmaster furnace and it leaked too.  I went and got some flat strip stock, cut it into pieces and had a metal shop curve it for me to weld it together and then to the bottom of the tank.

My manual for the furnace says the pump should run continuously while the furnace is fired to keep the temperatures constant in the furnace.  Cycling will allow a build-up of heat.  You deal with either it being a bit cold or too warm inside or I guess you build a system to dump the heat outside.  I typically run my LP heat until the temperature is constantly below 50 degrees and then turn to the furnace.    

[thecfarm]

Yes, for commercial use, home use.
But I do fill my OWB about once a  month. Had it since 2007 with no problems, so far!!!

[barbender]

The reason I run the primary/secondary loop set up is that the primary loop can circulate all the time. You have less issues with getting air in the system, and it keeps the temp in the boiler evened out. 
 
 It doesn't heat the house up, other than the mechanical room where the primary loop comes in to feed the secondaries. When my house thermostats call for heat, they kick on the pump on the secondary heating loops. Those pull hot water off of the primary loop, through a mixing valve to temper the water temp down to the desired level. 

 If you have in floor heat, you would almost have to run a secondary loop because the 180° water the OWB produces is "too dang hot!" as my HVAC father in law put it😊 Getting the water temp above 100-110 gets pretty warm on the feet.

[doc henderson]

we have a mixing valve, so the cooler circulating water is mixed with hotter water in a ratio to keep the floor heat water temp less than the actual boiler water.  The water heater is a closed system using a coil to heat domestic water without mixing.  one of our zones, upstairs, is a forced air with water to air heat exchanger.

[azmtnman]

I hadn't thought about the floor heat being too hot.  headscratchI am familiar enough with mixing valves and not a fan. Is there a different one than for tempering domestic hot water? Those also take a cold supply.
You guys are making me think!!! arg-smiley

In my HVAC career, I designed and redesigned a lot of system controls. I loved doing that but I was spending someone else's money!  :D I am also trying to make this as simple as possible with as few parts to fail as possible so the crew that lives here with us can use and understand it and know what's going on with it if I'm not here.
  
    Thanks for all the help. 

 

[doc henderson]

If the floor water is too hot, it can get ahead, and by the time the room temp kicks off the thermostat, there is much heat in the floor.  they want our floor heat water to be just over 105 to 120.  we need our water hotter.  I think the OWB have controls for the damper/fan.  I can get a pic you like of the valve.  this is for proportioning the hot water getting into a cool circuit, vs just recirculating or full on hot.  

[barbender]

 My loops with the mixing/tempering valve is somewhat of a head scratcher, but not really complicated. I'd take a picture but for the fact that the flux I was using when soldering was not doing its thing, and I'm ashamed of how it looks🤦😂 It's bad enough that I will pull it down and redo it at some point😊 I'll try to make a diagram of it. 

 Basically, the parallel loops just re-circulate their own water, and the mixing valve allows enough hot water from the main loop to keep the temp up. There is no cold water make up.

[azmtnman]

I'd take a picture but for the fact that the flux I was using when soldering was not doing its thing, and I'm ashamed of how it looks🤦😂 

Just post your pics. You'll get no judgement from me!
I have hard soldered a lot in my life (15% silver) and have done a fair amount of soft soldering. Big stuff--2" to 4". I never got it neat. The old plumbers showed me to wipe the soft solder joint and make it purty! I did that until my solder didn't flow and a 2" water line above a hotel laundry room came lose the night after we installed it. I became content with ugly but functional solder joints!

[azmtnman]

Another question:
  My son-in-law told me he thought the combustion blower (one he put on) was too small.
  This thing NEVER has flame even when the blower is on and just smolders all the time. IT IS VERY EASY ON WOOD. It stays "burning" but smokes a lot when on but not a concern because it is west of the house and my nearest neighbor is more than a 1/4 mile away. I also have it set to come on at 150 and off at 170. 
  Would a bigger blower be  better/more efficient? 
  Right now, I am just heating a 1600 sq. ft. house with 6" insulation in the walls. But I am going to add the 650 sqft shop to it hopefully soon.

[doc henderson]

Shooting from the hip.  how about a second fan and stage them.  i think it would increase temp faster with the option for more air.  the smoke would mean it is starved for air a bit, I would think, or temp too low to burn the volatiles.  with the right ration of heat, fuel and air (oxygen) the fuel is all heat, and no smoke.  most smoke (not water vapor) is unburnt fuel.

so, at start up and in a low range of temps, both run and get the ball rolling, and at operating temp only one runs.  you can then adjust the ranges based on how it operates.

[barbender]

 My fan is pretty small, but it pushes enough air to really get the stove hot and burn whatever junk wood I put in it. It also sends a lot of heat up the chimney, you can actually see a flame coming out of it when burning dry pine etc. So it's great for getting a fire going, and recovery.  

 I've always thought it would be more efficient to have a 2 stage aquastat on it, stage 1 just a damper would open. If that didn't recover the temp, then stage 2 the fan would kick on. But, being that all I burn is junk from my firewood and sawmill operations, it's not much of a concern- I don't get enough of it burned as it is🤷

 If I was burning a pile of nice, seasoned hardwoods that I paid for, I would do some work to chase that effeciency.

[trapper]

Are you using dry wood?

[azmtnman]

Thanks for the replies. I've been busier than a one-legged man in a butt kicking contest!
I'm burning everything! Most is dry, sometimes half rotten bark boards. I did get a truckload of alligator juniper to help keep my less-than-stellar wood burning.
  I like the idea of a 2nd stage fan and have an idea for a design. I would probably put a delay-on timer on the 2nd stage so the 1st stage would run for 10 minutes then, if it didn't get up to temp in that amount of time, it would kick on high fire. I think I'll use a 120 volt leaf blower for the high-fire fan.

[gspren]

I'd use something less powerful than a leaf blower!

[doc henderson]

could also direct some piping so it is blowing from under the stack to get it going.  should be able to get an industrial fan cheap.  you can duct it back from the stove, so it does not get too hot.

[barbender]

My stove is equipped with a small Dayton brand blower. They are pretty cheap ($100 or so iirc), move more than enough air, and last for years. I just replaced ours for the second time, in about 15 years of operation.

[thecfarm]

I think I have the same type of blower on my Heatmor.

[doctorb]

I haven't read the OWB thread in years!  You guys reminded me of the labor of love caring for my CB 2300.  I enjoyed the troubleshooting, the tinkering, the wood pile creation and depletion, and being outside with my dog Buzz.