My 10 yrs. experience with a Central Boiler

[twodeep]

Just today 10/31/2009 I fired up my Central Boiler Cl-45 to start it's 11th season.

I use it to heat my 1999 1800 sq. ft log home, the hot water for the home and a 450 sq. ft attached log garage (the garage heated only to about 60 degrees).  The logs in the home are large, averaging 14" in diameter if I remember correctly, so they provide a good R insulation value.   

It's worked wonderfully but my big complaint is it's wood usage.  It is located 100' from the house and the pex pipes are buried two feet surrounded by the very thick and expensive insulation that Central Boiler sold.  I live in Southwest Washington so we have mostly mild temperatures in the winter.  I have the burner fired up from Nov.1 thru the end of May.  Still I burn 11 cords per year.  I live on 59 acres and usually burn mostly seasoned alder, or seasoned hemlock or even some spruce if windstorms take them down. 

With our prevailing south wind, I placed the boiler north of the house.  Yeah it can send up a lot of smoke as the wood in this country will always contain some moisture no matter how well seasoned, but living remote it is no problem at all for me.

I'm on my 3rd solenoid.  I've had to replace the water thermostat twice.  I'm on my 2nd or 3rd taco pump cartridge.  Other than those three items I've  had no other problems such as warped doors or leaks .... until today that is.

Before I fired up the unit up today, I noticed the water level had RISEN from it's "safe" level that I ended the season with last June 1st  to almost "full".  That made no sense to me whatsoever as this was a cold temperature level.  Of course as the burner water heated up today the water expanded and thus began spewing out the top of the plastic level indicator tube. 

I'm totally mystified by this. What could cause "more" water to enter the unit.  The only thing I can come up with makes me shudder.  Could there be a leak between the house water and boiler water in the heat exchanger on the hot water heater?  Whoa, that scares me terribly.  That would also mean my house water is contaminated with the boiler water and all it's anti-rust chemicals.  Fortunately I don't drink from the hot water spigots, but I doubt that the hot water and cold water pipes are totally isolated, are they?   Thankfully I use 3 different 10 inch filters to filter my drinking water, but still I suspect all the caustic chemicals wouldn't be filter out.

The only thing that doesn't make sense with this theory is that my taco circulating pump was powered off during the entire off season time so I wouldn't think it would have been adding water to the boiler??  Unless the pressure of the house water was causing it to happen.

I am anxiously awaiting Monday so I can call my very favorite  Central Boiler tech and discuss this situation with him.  Until then I will drink only beer.       

           

[beenthere]

Isn't your house water pressure a few psi more than your boiler water psi? On first blush, sounds like you might be pushing domestic water into the boiler and contaminating it.

How do you fill the boiler? With manual valve or automatic valve?

[tonto]

I had this problem with my new CB5036. The boiler is piped directly to the oil boiler and  I shut the feed valve off from my domestic water thus depressurizing the oil boiler. Well that feed vale, maybe 10-15 years old, was not completely shutting off and adding 2-3 gallons of water everyday. Made me crazy till I figured it out. Changed the valve and all is well. Tonto.

[thecfarm]

twodeep,welcome to the forum.I have a Heatmor.You are saying you are burning hemlock and spruce.I would call both of these a softwood here in Maine.I have burned both kind and it does not last like hardwood.Hemlock would last better than spruce,I would think.Hemlock will coal down some.I have cut and split piles of softwood thinking that's a lot of wood.Two weeks later it is well on it's way of being gone.Doing the same with hardwood,makes a big difference.I think your 11 cord is not bad.Have you ever burned all hardwood in it for a month?I cut and split a lot less wood when I am using hardwood compare to softwood.

[woodmills1]

I live in NH and burned 28 cord last year, mostly ( 60-70%) pine, would probably use half that in all well seasoned hardwood

[twodeep]

Thank you for the welcome Cfarm (can I not reply directly to the poster or is the only option to tack a post onto the end of all the others?).

You make me feel a little better when you said you didn't think 11 cords was horrible.  The hemlock I burn is Western Hemlock, usually huge pieces split just enough where I can lift them. The last few years windstorms have toppled several of the bigs ones (like 2 1/2 feet diameter).  Any conifer I believe is considered to be a softwood.  Mostly through the years though I burn alder (considered to be a hardwood because it's a deciduous.)  But I think of it as being softer than hemlock.  It's a good burning wood though, and doesn't leave much in the way of coals.  But my favorite wood to burn is Sitka Spruce.  I think it does burn  faster as you suspected but it leaves almost no coals.   I've had 3 monster spruce come down in the windstorms of the past few years so I've been burning quite a lot of it.   Still, alder is my mainstay as it is the only species I will fall for firewood.

I see where woodmills1 burned 28 cords in NH.  Wow, although that is a much colder climate than mine, it makes me feel silly for whining about my 11 cords.  What kind of Pine I wonder?   We don't have much pine on this side of the Cascades but I've burned plenty of Ponderosa and Lodgepole (Jack Pine) in my hunting camps east of the mountains.  I think they are both excellent woods to burn.   

Regarding my problem of "gaining" water in my Central Boiler.  My method of adding water is pretty low tech.  I stick a hose in the vent tube at the top. I rarely have to add water so it's not an inconvenience, and the method does eliminate a bad filler valve or any thing of that sort as being the problem.  It almost has to be coming from the house water through some kind of leak in the water to water heat exchanger on the hot water heater.

I talked to a Central Boiler tech yesterday.  He hadn't ever heard of the problem and was going to have to discuss it with the senior tech (the one I was trying to get hold of in the first place). They haven't called me back yet.  I have a feeling they're doing some digging on this as this could be a horrible problem if it has resulted in drinking water contaminated with the very caustic anti-rust inhibitors that circulate within the wood burner.  Yikes!     

[rowerwet]

  I have a feeling they're doing some digging on this as this could be a horrible problem if it has resulted in drinking water contaminated with the very caustic anti-rust inhibitors that circulate within the wood burner.  Yikes!     

as posted above, your house drinking water is near 60 psi, the boiler water is unpressurized, any leaks will go into the boiler, no contamination can get into your drinking water. If any leaks are possible it would be a pin hole at most or you would have a fountain on your OWB. The only real way to check for that would be to monitor the level over each week when the water temp is at the same amount each time. If it creeps up you have a pin hole leak in the HX if it is stable you have condensation, rain, or something else going on.
on my OPB I have a ball valve hooked to cold water supply plumbed into the boiler loop to fill my tank.

[JSNH]

I see you replaced your water thermostat twice. Is it the digital one? What did it do? Mine is 3 years old and I caught it doing some weird things a few weeks ago. It was short cycling cilcking on and turning off after a few minutes. I looked at the display and the numbers were jumping around. I checked the wires and nothing was loose. I called the CB dealer and a new water thermostat was $230. I looked at it and is is made by Dwyer I ordered a spare directly from them with a new sensor for $60. The old one for some reason is working normally again but I have a spare on hand. The only diffrence is the spare has a red display.

[JJ]

     

on my OPB I have a ball valve hooked to cold water supply plumbed into the boiler loop to fill my tank.
[/quote]

I did same on my boiler; plumbed water supply right to cold water return.  I did add check valve after ball valve just in case.

Makes filling boiler tank easy as I just open valve on cold water return at the OWB unit, and watch water level at boiler to fill.

        JJ