The Forestry Forum

General Forestry => Firewood and Wood Heating => Topic started by: Jbern on November 07, 2017, 07:02:34 AM

Title: Centrl boiler classic runs hot
Post by: Jbern on November 07, 2017, 07:02:34 AM
Im new to the OWB heat. I bought a newer house that uses OWB heat exclusively. I hve a 2year old central boiler classic, I believe 4030 is the model. When we bought the home I was told that these things are great and easy to maintain.  So far it's been a nightmare. I have consistent boil over issues.  I changed door gasket at the dealers advice, seemed to help a little but not much. I checked everywhere on this thing for air leaks, then noticed the port for the Beckett oil gun leaked air, so I insulated that better. Seemed to work, then boil again. Had a buddy take a look, turns out the damper was slightly warped. We filed it flat and seemed like problem solved. I haven't had another boil over yet however it still runs hot...almost 200 if heat to kick on in house. Do these things run hot or should it stay closer to set point regardless of outside temp and amount of heat house is calling for. Last thing I'm thinking is inside circulating pump being oversized? Not sure if that would affect my thing.
Title: Re: Centrl boiler classic runs hot
Post by: Roger2561 on November 07, 2017, 01:08:54 PM
Did you overfill the OWB with water?  One the rear of my E-Classic 1400 I have a site tube that has a line to indicate how much water I have in it.  When water gets hot it expands and if I fill it so that the water is above that line it has no where to go but out the top of the fill tube on the top of the OWB.  Do you know if there is a way to lower the high set point on your OWB?  It can't hurt to lower it.  Roger
Title: Re: Centrl boiler classic runs hot
Post by: thecfarm on November 07, 2017, 01:27:36 PM
Jbern,welcome to the forum.
I have something on the back of my OWB that sets a high and low when the fans come on. It has temps numbers on it. Mine are set about 185°. So when the water temp hits 185° the fans shut down. A few times I had something that kept the flapper over and the OWB was over 200.
Title: Re: Centrl boiler classic runs hot
Post by: davewittwer on November 07, 2017, 04:08:39 PM
My CB Classic has a low and high set point.  I usually notice that once it hits the high point the temp will continue to climb at least 5 degrees past the high set point.  I usually set mine at 185.  I have also had issues with the solenoid contacts sticking with creosote.  I try and clean once a month with WD-40 to prevent the solenoid from sticking open.  What are your high and low set points on the boiler?
Title: Re: Centrl boiler classic runs hot
Post by: Jbern on November 07, 2017, 08:11:07 PM
My high is 185, my low is 175. I don't have a blower just the damper. I tried lowering high temp to 180 to give some leeway. If the house don't call for heat it will climb to 200. Local dealer said it shouldn't do that. Said I have air leak somewhere and I need to find it. Well I've been all around this thing not sure what else is leaking air. Does any one know how tight a seal that damper should make?
Title: Re: Centrl boiler classic runs hot
Post by: Gearbox on November 07, 2017, 08:31:44 PM
If the weather is still warm you may need to lower the set point to 160 to give it room . that wood has to get rid of the heat that is in the coals outside air or not . Mine will creep 10 on a warm day .
Title: Re: Centrl boiler classic runs hot
Post by: E Yoder on November 07, 2017, 09:17:05 PM
Could be a sticking solenoid. When it creeps up temp check to see if it's stuck open. 
Do you have a continuous running pump? If it starts and stops it'll boil on top on warm days with no call for heat.
It's either an air leak or no flow.
Title: Re: Centrl boiler classic runs hot
Post by: petefrom bearswamp on November 08, 2017, 08:37:49 AM
Been running mine all summer for domestic HW using hemlock slabs.
It ran hot and boiled a couple of times.
I lowered the temp differential to 140-150 and havent had any probs since.
Will return to a hotter temp whe it gets cold.
I s yours a classic or eclassic?
Title: Re: Centrl boiler classic runs hot
Post by: overclocking on November 08, 2017, 09:02:09 AM
You do have an air leak some where. I run mine at 190 because my run to my house is so long. If your creeping 15* then you absolutely have an air leak or your not circulating. They are tricky to find. I'm not overly familiar with that exact model, does it have solenoids? One could be sticking.
Title: Re: Centrl boiler classic runs hot
Post by: coxy on November 08, 2017, 07:22:18 PM
put a straight edge on the door it maybe warped that's what happened to mine is the damper in the side or the door like pete asked is it classic or eclassic   
Title: Re: Centrl boiler classic runs hot
Post by: boilerman101 on November 08, 2017, 09:39:44 PM
I see on jbern's first post this is a Classic 4030 which has a small firebox. I agree that there is a small amount of air seeping into the firebox somewhere allowing the temp creep. jbern you said you found some air gap around the Beckett DF burner? Take a closer look at where the burner tube slides into the sleeve and be sure to pack any gap in that area with insulation or something to make sure no air is still sneaking in through that area. Also, is their a chimney reducer in the back of the chimney tee reducing chimney tee passage down to 6"? It is helpful to not over draw that small firebox through chimney air draw.
Title: Re: Centrl boiler classic runs hot
Post by: petefrom bearswamp on November 09, 2017, 08:37:46 AM
At my work 40 years ago we had a monster wood furnace with an oil burner stuck into the side of the firebox
There was a flapper valve which was supposed to close when the oil was not in use.
This would crap up with creosote and fail to close resulting in overheating when on wood.
I am not familiar with a classic with an oil burner option, but maybe this is what happens.
Title: Re: Centrl boiler classic runs hot
Post by: Ford_man on November 12, 2017, 05:09:43 PM
Your Door should latch reasonably hard, but not so hard it will break something.
Title: Re: Centrl boiler classic runs hot
Post by: BLink on November 12, 2017, 08:47:11 PM
To check the seal on your door, open the door and put a dollar bill inside and hold on to it outside and close and latch the door. Pull on the bill. If it comes out, it is too loose. Work your way around the door checking it every little ways.

My door has some holes rusted thru to the fan chamber but it is about 20 years old.
Title: Re: Centrl boiler classic runs hot
Post by: Jbern on November 14, 2017, 09:51:18 AM
Turns out, at least I think that the damper was slightly warped. Dollar bill slid easily all around it. The area that the damper seats was lso sightly not flat. Filed the seat, and replaced damper. Runs alot better. It still seems to creep up a little on warmer days but not much. I'm hoping I got it licked. Darn creosote seems to be a burden I Wil deal with alot now. I'm amazed that so small of a air leak in that damper would cause all that havoc. I'm also amazed that if it's that important why CB put so little thought into that damper.  Only other thing I need to figure out is how much wood should I be loading into this thing? I'm pretty sure I'm putting too much, but am afraid to put too little I've got little kids in the house and don't want to them to get cold. I've been loading up, it does burn but I'm getting  a ton of hot coals building up. Not too much ash just big hot coals. Any advice on the daily fill would be great.  I fill generally 6am and 7 pm. Thanks
Title: Re: Centrl boiler classic runs hot
Post by: coxy on November 14, 2017, 11:10:46 AM
what is the water temp before you fill it  with mine when its warm/cool ill let the water temp get down to 150 then fill it up this way it burns the coals down but when it gets cold say 20s all day it will eat the coals to ash
Title: Re: Centrl boiler classic runs hot
Post by: JSNH on November 14, 2017, 12:15:00 PM
I have a 5036 and a coworker has one. I have a greater heat load then him and I burn mostly soft wood where he burns hardwood. He has had issues with going over temp. I looked at his and how he was loading it. He was overloading it and the wood was pretty far back from the door at least 8". He was building up creosote on the damper that was preventing it from fully closing. Mine runs more with the softwood and I charge the wood very close to the door. I don't build up creosote on the damper.  He started loading less wood and puts it closer to the door. His creosote issue went away. Neither of these have the oil burner. As others have pointed out extra air could be coming from there.
Title: Re: Centrl boiler classic runs hot
Post by: BLink on November 14, 2017, 11:16:39 PM
The door should be tight enough that you can not pull it out. Tighten your door up if there is any way to adjust it.
Green wood make lots of coals whereas drier wood will make ashes.
Title: Re: Centrl boiler classic runs hot
Post by: Dana on November 16, 2017, 07:33:10 PM
Look on the stove where the door gasket seals. On mine the steel had deteriorated and was allowing the air in. 1/2 hour with the mig welder and grinder and it's better than new as I built the steel back too the original height but made it thicker near the seal.
Title: Re: Centrl boiler classic runs hot
Post by: Logging logginglogging on December 21, 2017, 11:24:29 AM
as for loading, try reducing a bit at a time until you see whats right for the heat load you draw. The less wood the cleaner and hotter it will burn. you will find a balance between that and load times. I like to keep the boiler on the hungry side and it stays quite clean this way. The more wood the more moisture you need to burn off to make heat and the more goo and creosote it will create.
Title: Re: Centrl boiler classic runs hot
Post by: petefrom bearswamp on December 22, 2017, 08:17:59 AM
I agree with Logging, try reducing the load size.
I seldom load more than 10 fair sized chunks in mine twice a day.
About 7AM and again around 4:30PM
In super cold weather it burns to ash and a few coals over night.
Title: Re: Centrl boiler classic runs hot
Post by: coxy on December 22, 2017, 04:32:47 PM
try putting another dump zone in like an old cast iron radiator or 2 in a cold/cool spot in the house 
Title: Re: Centrl boiler classic runs hot
Post by: BLink on December 24, 2017, 06:33:48 PM
If it is air tight, like it is designed, you should be able to fill it all of the way up and it should allow only enough air in to keep the  water temp where it should be.
Title: Re: Centrl boiler classic runs hot
Post by: E Yoder on December 25, 2017, 09:09:34 AM
Quote from: BLink on December 24, 2017, 06:33:48 PM
If it is air tight, like it is designed, you should be able to fill it all of the way up and it should allow only enough air in to keep the  water temp where it should be.
I agree, if it's air tight like it should be it should never boil. Shouldn't need a dump zone.
Title: Re: Centrl boiler classic runs hot
Post by: coxy on December 27, 2017, 07:04:28 AM
try changing the aqua stat  in the stove it maybe bad and letting it run hot my old stove I had an adjustable aqua stat and ran it at 200  my newer stove only goes to 190  that extra 10 degrees makes a big difference with base board hot water  :)