OWB winter shutdown

[doctorb]

I have never,ever had a back issue before, but 10 days ago I felt a pop and I am miserable.  Loading the OWB makes it worse, much worse, so I am going to go back to oil heat for a while. 

I thought it would be an interesting exercise to observe daily temps in my OWB.  My plan, at the onset, is to just run the circulatory pump at the stove to my basement, without having Any flow through the heat exchanger.  In other words, let's see how long the temps in the stove remain above freezing.  I will have to, if the weather stays cold enough, eventually open the loop to the heat exchanger to transfer a little heat from the oil furnace back to the OWB to prevent freezing.

I'll  try and post daily water temps, as well as outside high and low for the day, to give us some idea as to How these things behave.  As there have been several threads on the subject of shutdown, I though a little data added to the discussion might be helpful.  Might as well make the best of a painful situation!

Doctorb

[Roxie]

You should see a doctor about that back.  Sure hope you feel better soon!   

[bandmiller2]

Always the man of science,taking a bad situation and learning from it.Frank C.

[stumper]

I know that Doctors are almost all quacks ;D, but please find one knowledgeable in back issues, see them and take their advice!!!   

I blew out a disk and did not see a knowledgable doctor until it was too late (worker comp doctor only wanted to keep the cost down, not make me better- I still wonder what oath he took).  While I am not in pain I have lost a portion of the feeling in my left leg and will live with that for the rest of my life.

My advice is ignore what you learned as a boy.  Specifically, "Tough it out, Walk it off, No pain No gain, ect...."  Listen to what your body is telling you and do not push things. 

Hope you heal well and get back to the things you love as quickly as possible!  Please keep us posted on both your recovery and your boiler.

[Norm]

Boy what some people won't do to get out of some work.... :D

I'm sure your wife and daughter would be more than happy to do the wood work while your laid up. Please don't tell them I suggested it.  ;)

[thecfarm]

Good luck with your back. Will be interesting to see your numbers.

[DouginUtah]

Have you considered hiring a teenager to load the OWB once or twice a day?

When I was fourteen I walked half a mile every winter day to put coal in a stoker for an old couple.

[chevytaHOE5674]

When I leave town for any length of time I pay the neighbor kid a couple bucks to load the OWB. He just gets on/off the school bus at my house instead of his own and then walks the 1/2 mile down the road to his place. Paying him is a whole lot cheaper than buying propane.

[doctorb]

Thanks for the suggestions.  Yes, I thought of having my wife and daughter load the stove, but my wife's kind of afraid of things like fire, and she's put a little of that fear into my daughter.  As I hope this is a short-term problem, I would like to avoid teaching someone what this stove needs in daily maintenance.  Unfortunately, I am one of those people who is a doer, and I would probably not leave that OWB alone if it's still up and running.  So, the best thing for my back is to buy a couple of weeks worth of heating oil and get better.

The furnace is out this AM.  Last fuel was placed yesterday AM (about 2/3 full) and allowed to go out.  I was not able to shut down the fans before bed last PM, so some cool air blew into the firebox with a dying fire all last night.

Day #1:
OWB water temp this AM:  159 degrees
Air temp this AM:  34 degrees
Hig temp this afternoon:  mid-40's

[buckgrunt]

My theory is that as long as the circulation pump is kept on, the water in your OWB or your underground piping will never freeze.  I say this because when I lived in Central Quebec, our well water lines were not deep enough to prevent freezing.  To solve this, we  kept a "drip" going in our bathroom faucet to keep the water flowing, thus preventing any freeze up.   

[hockeyguy]

Hope you are back to normal soon. I think most of us have suffered from back pain at one time or another and can understand the pain your in. Thanks for the data on  the boiler, it's good to know. Just the thought of burning oil is making my back act up.  :'(
Best wishes on a speedy recovery.

[firechief]

Sorry to hear about the bad back Doc, but, in the name of OWB science, thanks for posting the numbers for us.

[submarinesailor]

So, the best thing for my back is to buy a couple of weeks worth of heating oil and get better.

Doctor - just as a heads up, heating oil is currently at or very near record highs : : : : :.  So watch out for sticker shock.

Bruce

[doctorb]

Bruce-

Timing in life is everything!  On the good side, we're forecast to stay on the warm side for a little while, so the amount of heat I will need may be less than most late January weeks.  On the bad side, I know that heating oil and gasoline prices are up and headed higher.  Fortunately, I filled those tanks this October when the price was about $3.60 / gallon, and they are still full.  Heck, that's close to what gasoline prices are now!  I am sure heating oil is approaching or passed the $4.00/gal mark by now.

Checked the OWB late this afternoon:  139 degrees

Buckgrunt-  if I had to bet, your theory would be correct, unless an extremely long period of subnormal temps occurred.

[boilerman101]

Hey Doc, any good chiropractors in your area? I've had great luck with a chiropractor fixing my overworked back up fast!
In the meanwhile, you might try cracking back the ball valve on your return line at least halfway or more at the furnace to slow the flow. You should not need normal full gpm flow to keep from freezing and that should keep furnace water temp up longer.
Good luck with the back!

[beenthere]

Looks like you are pretty close with oil prices.

http://www.eia.gov/petroleum/heatingoilpropane/

[doctorb]

Boilerman-

I presume that partially closing the valve restricts flow, but also increases the resistance against which the pump must push to move the water.  Is it harmful to the pump for it to have to work against this increased resistance to flow?

[boilerman101]

Doc, not sure which pump you are using but most can handle and are rated for much more "head" pressure than what we are running on most of our systems. I would be comfortable with some extra restiction for a short term. And yes, my thinking is to slow the flow and temp drop in the furnace. Especially with your good Thermopex delivery line.

[doctorb]

Day #2:

OWB water temp this AM:  119 degrees

Outside temp:  36 degrees
Forcast high in mid-40's

[Norm]

How's the back feeling?

[doctorb]

Actually, I have missed a total of 4 loadings and it is improving!  Thanks for asking.

[stumper]

We had southern temps like this eariler in the week.  Seemed like half of the Maine state was driving with their window down enjoying the warm temps.

[gspren]

Bruce-

I am sure heating oil is approaching or passed the $4.00/gal mark by now.

Actually just yesterday I wrote a check to cover 300 gallons of heating oil at the house I rent out,  :'( $3.629 gallon delivered last week. My tennents are supposed to pay but they always have a story, maybe when their tax refund comes :

[thecfarm]

Take care of that back. I have a brother that has to be careful just picking a pencil up off the floor.

[doctorb]

Day # 3:

OWB water temp:  91 degrees

AM outside temp:  52 degrees!
Expected highs today above 60 degrees!

The back continues to improve, but it's not gone yet and I'm not rushing it.  I can pick things up off the floor OK now.  One of my problems is that I can't escape the use of lead aprons in the OR, as much of my surgery uses intraoperative x-ray (called fluoroscopy).  They are heavy.  It's like wearing a 20-30 pack and standing for hours.  UggHH.

I think, for the experiment's sake, that leaving the pump running was a good idea during this shutdown because it gives a better idea of the temp loss per day under winter conditions.  However, we have had anything but winter conditions since this started.  We've not had a single night below freezing!  Look at those daytime temps expected today!  We don't know how much the ambient outside temp effects the temp drop.

Anyway, I shut the circulating pump off this morning.  It's not going to go below freezing here for another couple of days.  We'll see if the amount of temp drop per day decreases with the pump off.  Certainly it should, but it also should decrease less with the outside temps being so warm.

[Dean186]

Doctorb,

Sorry to hear your back is bothering you.   

My thoughts have always been; If the pump is left running, it would take many days before freezing is a concern in an OWB.

Good post, I will be monitoring your posted information. 

Dean

[doctorb]

gspren-

Maybe it's due to state taxes, a torture at which we are really experienced here in Maryland, but the average price for heating oil in Md. was $3.97/gal on 1/23/12.  Found a state web site with that figure and called my supplier for verification. I may be moving to Pa!  Having driven north through Pennsylvania and New York to Canada countless times, I can assure you that Pa. gas prices are ALWAYS significantly lower than Md. prices.  So i'll bet that the difference between what you paid and what I would have to pay per gallon is state tax related.

[gspren]

Doctorb,
  I live close to the MD line and just recently retired from Aberdeen Proving Ground so for over 26 years I drove through Maryland 5 days a week and the prices have bounced back and forth as to where its lower, I think its a crime but our gas went up 0.10 yesterday. A lot of people move from MD to PA when they retire to escape the state income tax on pensions. I hope your back heals quick but I have antifreeze in mine because like your wife mine won't touch the OWB. When I go to the hunting camp I shut down till I get back. Good luck!

[doctorb]

Day #4:

OWB water temp:  86 degrees

AM outside temperature:  31.5 degrees.  (Oh my!  below freezing!)
Expected high temp today:  50 degrees

So the decrease in temp with the circulating pumps off is relatively minor compared to the loss of at least 20 degrees per day with them running.  I let the pumps run for about five minutes and shut them off again. 

[upsnake]

Doc B, you are referring to the circ pump from the owb to the house and back right?

If so are you concerned with the water freezing at inside the pex, or at the fittings at the back of the owb etc.

(i know with 50 degree days it is not a big concern but if the weather was colder)

[doctorb]

Upsnake-

Yes, I think the area of biggest freezing potential is where the pipes exit the ground at the back of the stove.  Interestingly, I just removed the back panel, and I had forgotten that I had installed temp gauges on both the inflow and outflow lines. 

The OWB temp is:  85 degrees

The outflow temp is:  78 degrees
The inflow temp is:  72 degrees

So the temp of the stove readout is not truly equal to the temps of the lines as the enter and exit the stove.  Now we don't know the calibration of all these thermometers, but I think it shows you have to be thinking line temperature in addition to OWB water temp.

And yes, I am referring to the pump at the back of the stove that sends the water from the OWB to my house and back.

[doctorb]

Day #5:

OWB water temp:  82 degrees

Outside AM temp:  32 degrees
Expected highs today in the 40's

Temps at back of stove:
     Outflow:  76 degrees
     Inflow:  52 degrees

Flipped the pump on for five minutes or so to increase the temp in the lines.  Pump off again for another day.

I think one can certainly conclude that the OWB is well insulated and, withou circulation, maintains temp very, very well.  Without the pump running the OWB temp has only fallen 9 degrees in 48 hours.

[boilerman101]

Hey Doc, hope the back is getting better and you will be back chuck'n wood and saving money again soon.
Before firing up again, you may want to check out CB's Eclassic initial start up video:   http://www.youtube.com/centralboilerinc#p/u/0/Cea9CV4kdHY
I took my E2400 water from 50 degrees backup to 185 in less than 2 1/2 hours, by following this method.
Would be interesting to see if it would take more or less time with your E2300.
Either way, I found this a great method to rebuild a coal bed fast!

[doctorb]

Day#6:

OWB water temp:  76 degrees

Outside AM temp:  28 degrees with a dusting of snow!
Expected high temp:  42 degrees

I flipped the pump on this morning because of that below freezing temp.  The rest of the week is predicted to be warm, so I'll turn it off tonight or tomorrow, dependent upon the temperature.

Boilerman - thanks for the heads up on the video.  I have not done it exactly like that before, and will give it a try on my restart.  My back is better, thanks, but it still pulls a bit.  I don't think that I'm being a wimp about it, I just think I should feel pretty normal before loading wood twice a day.  The great thing has been our very mild winter.  Yes, I'm burning oil now, but it could have been a lot worse.

[mrwood]

Boy dr b. sorry to hear about your pain and I hope you feel better soon. This would be a trie hurt for me. First the physical pain. Second the wallet pain for the oil. And third the emotional pain for not being aloud to "play" with my stove. All on my friends laugh at me because of how excited I get about my stove but after all of my hard work over the summer and great savings on heat, the stove is very rewarding and exciting. But I too have fuel oil and I think I would roll out there in a wheel chair before I had to pay for oil again. Yuck. I was glad to kiss that bill goodbye

[doctorb]

Day #7:

OWB water temp:  66 degrees

Outside AM temp:  34 degrees
Expected high near 60 degrees today!

Pump ran for 24 hours until this AM, when I shut it off.

I have a 300 foot run from my shed to my house.  I wonder if the ground temp would warm the pipes a little once the temp in the circulating water approached 50 degrees.  If true, this fact would support the idea that the OWB, or it's pipes, would not freeze if the circulating pump was left running.  Of course, this also assumes that the pipes be buried deep enough to be "protected" by the inherent temp of the earth, i.e., be below the freeze line.

[doctorb]

Day#8:

OWB temp this AM:  65 degrees

Outdoor temp this AM:  51 degrees!

I wont continue to bore you guys with this.  Without subfreezing temps, all this info lacks significance.  I did learn a few things from this exercise, though.  Hope to be up and burning again soon.

[petefrom bearswamp]

doc
How deep are your lines?
Back in 94 I had a Taylor with a 125 foot run from the furnace to my house with the lines only about 1 1/2 ft deep.
I lost 7 to 9 degrees from the furnace to the house and the snow always melted over the lines even with 2 to 3 ft of snow.
I sold this after 3 years and burned oil until 2005 when I installed my classic.
I now have a run of only 30 ft or so and the heat loss is negligible, even with the lines only 1 ft deep.
I usually have at least 2 feet of snow over the line area almost all winter.
This warm winter is sure easy on the wood pile.
Hope you are better.
Pete

[doctorb]

My lines are about 3 feet down.  That was not my decision, but the decision of my dealer.  In my 300 foot run from my shed to the house I lose about 6-7 degrees each way.  I do not get snowmelt over the lines as the snow falls and the snow "sticks" evenly across the lawn .  As the snow pack ebbs, over the lines is the first to go, but the melting over my lines is not dramatic, and the rest of the lawn has pretty thin snow cover by the time the grass over the lines shows through.  So I realize I have heat loss, as do we all, but for my situation i think it's acceptable. 

By the calculations from Dean186's thread I linked to earlier, I am sure that, over the course of a full winter's heating, I am donating a cord or more of firewood to heat the ground.  If I knew then what I know now, I would spend the extra time and $ to do it by Dean's method.  however, I have no plans to rip up my lines anytime soon.

[DBRACKETT]

Personally I have enjoyed the stats it's that be prepared thing for me. Even though you've had almost ideal weather for a mid winter shutdown the temp readings have still given us something to go by especially in the first few days. No matter what weather conditions you have there will be a ton of differences between stove setups, even if it's as simple as the length of the pipe run. For instance your 300 ft is going to loose more heat than my 80 ft run just saying.
Dan

[doctorb]

DBRACKETT-

I think it's given me a handle on how the stove behaves without a fire.  I am much more confident now that, even with cold winter temps, if you leave the circulation pump running, it's going to take quite a few days to freeze, if ever.

And I agree that our individual set-ups play a role in the way each system will behave.

[doctorb]

Well, my back is still tight, but this weekend is forecast to actually feel like winter,  so I decided to start the OWB up this afternoon.  I followed some of the suggestions I saw on a CB video that was linked in an email or PM I was sent, which I can't find at the moment. 

Anyway, the start up went great. In 2.5 hours I went from56 degrees to 152 degrees.  Gassifying well.  I loaded it up and came in for the night.  I'll check the water temp coming into my basement from the stove in an hour or so.  When it reaches 180 degrees, I'll open the loops to my two basements and stop burning oil!

I find it interesting that my stove only got down to 56 degrees being off for 2 weeks in winter.  I
selected some days to shut the circulating pump down, but for the last 4-5 days I've left it on 24/7.  The system holds heat very well IMO, especially when the temperature gradients between the stove and the ground are small.  From this experiment, even though our temps have been mild, I am confident that I can leave the stove off and run the circ. Pump without fear of freezing for over a week or more.

[trapper]

We regulary leave the pump run when we go on vacation in the winter for two weeks with the gas furnace set at 50 degrees. The water in the OWB is normaly about 50 degrees when we get home.
Marv

[mrwood]

This has definetly been good info to know as I do not plan winter vacations it is nice to know that if something happens it should be ok. I know that for this process to work correctly for me I would have to bypass my thermostatic valve to allow my original furnace to add a little heat to my water. Thanks for the write up dr b

[Dean186]

I think it's given me a handle on how the stove behaves without a fire.  I am much more confident now that, even with cold winter temps, if you leave the circulation pump running, it's going to take quite a few days to freeze, if ever.

And I agree that our individual set-ups play a role in the way each system will behave.

doctorb, Thanks for sharing this important information.  I am sure it will help many OWB owners. 

The results you observed echos my thoughts I have posted in the past.  With the pump running, the likely event of the water freezing is slim and there is very little reason to add anti-freeze to the water. IMO

Glad to hear your back is better,

Dean

[Jack72]

Hey Doc

Im glad your back is better and stays that way.      This may sound dumb but    I know with this mild winter we are having in most area's             if it was much colder out and you were worried about it freezing       if you could run a electric cord through the reaction chamber and put a little heater (box heater w/fan and a thermostat)

in the firebox if that would help keep it much warmer just curious.          My wife is a school teacher and we never take winter vacations but if we ever did around christmas I would not want to bother my neighbor to keep it running.      Its either that or put 200 gals of glycol in the stove$$$$    Id rather not but it sounds like it made it along time for you.             Jack

[doctorb]

I would not add antifreeze to this system as it would take quite a few gallons to protect this volume of water, and my understanding is that, when that level of protection is reached, heat exchange is somewhat inhibited by the glycol.  (I don't know why that is, but I have read it in serveral different locations).

From this test, certainly a long winter weekend or more with no OWB fire should not be enough to threaten freezing of this system unless severe cold is present.  I think that just leaving the pump running keeps the areas in the system that are in jeopardy of freezing (pipes exiting and entering the ground at the back of the stove) from doing so.  I am pretty confident that these well insulated OWB's with high water volumes handle this situation pretty well.  My only change in my currrent practice will be to insulate the area of the stove where these pipes are located.

Running the OWB water through the heat exchanger will return some heat from the oil furnace to the OWB, but it appears mostly unnecessary to do this as a prevention of freezing.  To emphasize, I did NOT do this during this test.  If you use this method, the amount of heat draw from your oil furnace is substantial, and you will burn a bunch of oil which is probably a waste of that fuel, as the OWB is unlikely to freeze over several day span.

After this test, I have no plans to add any supplemental heater, as you suggested, to the system.

[r.man]

A friend of mine runs his air to air heat pump at both ends of the winter to conserve wood. His water rad is out of the furnace while the heat pump is running but he leaves his circulating pump on all the time. The air to air will keep up until about 10 degrees F so he will burn a bit of cardboard if his water temp gets close to 32. If I remember right he only has to do that every few days if it is quite cold.

[upsnake]

So question on leaving for a couple days with the OWB.

Through Doc B's experiment, I am worried about going out of town for a few days. My question though is for ppl that have forced air furnaces with two tstats.

I have my owb tstat set for 70, and then my propane tstat set for 50.

The problem is when the fuel is used up in the owb, the owb tstat is going to tell the furnace blower to stay on until the house is 70, but since the propane tstat is going to only heat the house to 50, the blower motor will stay on the whole time.

What i was thinking of doing is filling the owb up and then turning off the owb tstat and let the house just fall to 50 and let the propane furnace take over.

Anybody else go through this or have any better ideas?

Thanks
Jay

[doctorb]

Is your propane back-up heat for the OWB or do you have a propane fired hot air furnace separate from the OWB in your basement?

[upsnake]

Reg propane furnace in the basement, separate from the owb.

I have the classic CB forced air system setup.

http://www.centralboiler.com/forcedAir.php

[mrwood]

Upsnake brings up a very valid point. I have the same setup, and have often wonder the same thought. My OWB tstat is at 72 and my fuel oil is at 59 but even with the fuel oil kicking on at 59 the blower will still run 24/7 because it is tryin to heat my house to 72

[doctorb]

Do you have the ability to separate your OWB hot water loop in your basement from the heat exchanger?  Do you have the ability to shut down your OWB fans and leave the circulating pump still running?

If you are going away, why is your house thermostat set at 72?  Turn it down to 55.

[chevytaHOE5674]

My OWB and propane forced air furnace have separate T-stats in the house to trigger the furnace and blower. If I was to leave and let the boiler go out (hasn't happened yet) I would just turn the boiler T-stat lower than the propane one. That way the furnace blower would only run when the propane was on.

I also have a switch where I would turn off the draft fan on the OWB and leave the circ pump running. That way the water would circulate and keep the stove from freezing but the draft fan wouldn't start running as soon as the stove cooled off and continue running until I returned to fire up.

[upsnake]

Good points guys,

I am going to go be gone for 5 days, (in March, and with the weather we are having it is not that big of deal, but more wondering about the theory of it), what I was trying to do was "squeeze out" another day of heating the house from the owb, but that is where the furnace blower being on all the time problem comes in.

I could turn the owb tstat down below the propane furnace, and run the whole time off propane. Then just let the owb burn until the fire either goes out from lack of demand or it actually burns up all the fuel just maintaining its own temp. Which is prob what I am going to do.

It probably isn't that much of a difference in propane usage trying to get that one extra day of heat out of the owb, at the cost of running a half horse motor for 4 days straight.

Or I could have put in a 200 dollar internet controled tstat. hahahah  :D (yea right).


As far as turning the draft fan off, the e classic is smart enough to know when the FO goes out and will cut the draft blower, so I don't have to worry about that.

[chevytaHOE5674]

If you have your furnace blower (for your OWB) on a programmable T-stat you could probably program it to run for X amount of time after you leave and then bump down to a lower temp.