Buderus rumbling and draft problem?

Zman500

I recently had a new Buderus G-115 boiler installed with a reillo burner and Logamatic. I was away for 5 days and the thermostats were down low. When I returned, it was warm outside, about 70 deg so the logamatic was on summer mode and boiler temp about 90 deg. The house was cool so I raised the thermostats and circulator came on but boiler did not, because of summer mode. Boiler temp went down to 70s. I then reset the summer mode temp to 72 and boiler came on. However it made a rumbling sound and the draft vent on the flue was banging around, with exhaust coming out into the room. This continued for 3 minutes or so and the boiler started to heat up, but I shut it down with the logamatic off switch. A few minutes later I turned the switch on, and 30 seconds or so later the boiler came on and worked normally. Any ideas on what happened? I'm now concerned because if this happens again when I'm not home or asleep the room could get filled with exhaust! I will call my installer but would like to get educated here first.

kcopp

where is....

your chimney? If it is a cold outside chimney it might be that it was cold and had poor draft.

Zman500

Chimney

Chimney is behind the boiler on the outside. It probably was cold, although it was a warm day. I thought it is probably a poor draft issue, but never had this problem with the old boiler set up and certainly have been colder days than this.

kcopp

that may be true....

but if the boiler temp was low... and its a 3 pass boiler, the chimney will not pull much draft. Is it a riello burner?

icesailor

Rumbling Buderus:

In Massachusetts, it is illegal to install a new gas appliance on a 3 sided outside chimney. It will never get warm enough to get good draft. I know you have oil but the same rules of physics apply. The gas code and the oil burner code are two different codes and enforced by two different agencies.

In spite of what Buderus says and that some here will tell you about how to get a Buderus 115 boiler to stop this on cold start up, some of us have found that a refractory rug on the floor of the boiler will reflect heat from the flame of combustion, stops the cooling of the underside of the flame and stops the rumbling and smoking. You noticed that once the boiler started warming up, the smoking and rumbling stopped. If it is cold, and you have an outside chimney, it will never work well on a cold start, triple pass boiler when it starts cold. Once warmed up, it will work fine.

Mellow_2

this is a set up problem

I will say most brick chimneys are cold and oversized. Not the best way to run most new boilers. BUT..... the buderus boiler has baffles inside that can be removed to increase heat up the chimney. This will allow you to run the boiler with the correct draft.  You can run this boiler with better eff. if a metal liner is installed.  this would allow more heat to stay in the boiler by reducing the heat leaving the boiler.

That being said, the boiler smokes when cold because everything is cold ......... the burner needs to be adjusted to create a combustion chamber..... the manufacturer has pushed the burners blast tube into the boiler to create this chamber.... this combined with the correct nozzle and ajustments will allow this boiler to run.

You should have your service man work with buderus to get the best out of your new  boiler...

icesailor

Draft:

Let me understand this so I get it correctly.

Outside, three sided chimneys suck. Even you agree with this.

Inserting the burner farther into the chamber makes it hotter so it will smoke less. All those instructions I have been given about inserting burner ends past the face of the insertion are now wrong. It's OK and latent heat won't boil off fuel in the nozzle assembly or cause after drip. Putting "a metal liner" will help solve the problem.

And on and on.

Did you ever look closely through the inspection port and notice that when you first fire off a cold boiler, that has cold water returning through the bottom. that the oil in the bottom of the flame pattern goes below the flash point and drops to the cast iron floor of the boiler chamber and makes it wet? And then, as it gets hotter, it smokes like crazy until the bottom return water gets high enough to allow the bottom oil vapor to go above the flash point?  Like I have and others have.

And a Lynn refractory rug on the bottom solves the problem 100% of the time after proper combustion adjustments.

The only reason I do not install Buderus boilers. You do not advocate using a rug. It violates your listing. Funny, I'm not the only one suggesting rugs in boilers that smoke when cold.

Zman500

Poor Draft

Yes, I do have a three sided outside chimney, 50 years old, stone on the exterior. I suppose I didn't have this problem with the old boiler because it stayed hot all the time. Maybe a solution is to not let the temp go so low, via the logamatic. Still, I'll call the installer on Monday and see what they say.

Mellow_2

cold boiler

the problem is the fire trying to burn in a cold space. maybe the chamber rug will help this condition maybe not. The buderus boiler dosen't  come with a chamber in it. why not? If this is the solution why didn't the factory install one.....

 The problem is the burner.... the german burners( not avalible on a 115 boiler) have a chamber tube that inserts in to the boiler, allowing the fire to burn. I have seen this on the g125 boiler. all burners need a chamber to burn..... the factory has moved the tubes into the boiler just enough to warm the end quickly. this makes a combustion chamber at the end of the tube. I have installed and serviced hundreds of the 115 boilers and with the correct adjustment and no rug installed the boiler, the boilers run very clean. I have not seen any after drips from the nozzle or any reason to install a rug.

I do see very poor combustion IF!!  the controls allow a cold water return to keep the boiler cold for a long time. this is why the 2107 logomatic  control from buderus has pump logic to allow the boiler to warm up past condesation point before circulating the heat.

I would have the service man work with buderus to solve this problem the most eff. way or you could be lowering your boilers eff.      

Zman500

Yes

It is a Reillo burner

David Sutton_6

Burner and boiler set up

 this is what i have found to work and with adding a chamber, you are going to get some fire side condensation and having that rug in there will give it a good place to hide under, And yes i know some people actually open the door to clean the boiler, but after 30 yr doin this stuff there sure are a lot who dont, you can see it in the layers of the years  i call it ;-)

 with the 3 and 4 sec G-115'S With reillos



4 SEC. ...    remove nozzle replace with a 65x60w  increase pump presure from 145 to 175#   slide back the draw assm to 0 make sure electrodes are a good 3/16 or the withe of a #2 flat head ( remember its DC current). set with test kit 13 % 4-6 % o2 25 -35 ppm co



3 sec remove 65x60b install 50x70a pump presure to 175# same as above.



higher pump presure give you better atomization of the oil and a much more complete burn. and remember that stack temps are ajustable on these boilers



i Had all the problems mention above and this solved almost all of them .

icesailor

Cleaning Boilers:

Right you are David.

Every boiler that I clean that has a swing open door, I open up and suck the kibbles and bits out. And under every "rug" I find a feast for my soot sucking friend. The factory rug will only take a couple of cleanings. A Lynn one will take a lifetime of them. I pull it out in one piece.

I wonder if a Buderus without a rug runs better after a year when it has a good layer of kibbles and bits on the bottom to reflect the heat back into the flame like the rug does. Would this be called a DeFacto rug? 

Another thing, when you crank the pressure, the oil gets hotter due to the heat of what compression there is. The higher the compression, the greater the cooling upon release.

Big Ed_4

Massachusetts

I wonder who is making the rule in Massachusetts . No disrespect but I notice some of the rules up there just don't make sense . I can see a liner if poor draft but to condemn any outside chimney ? Another rule up there is how to pipe an outside tank ... Top feed only ? Ok so let the tank rot out .

ScottP

Buderus seasonal changes

I have a G125 BE boiler and it seems to barely be able to start with a poor draft chimney.  We have had Buderus and technicians here to inspect the installation.  We have a liner, 15' three sided outside chimney with poor draft in our new house.  Blowback is awful before it shuts down and the reset light comes on...Now, after blinking, it starts to restart itself without having to hit the reset button.  It has the barometric damper and I'd love to cover it with tin foil, however, would a fan in the duct work exhaust work?  Also, I have read a lot about changing the nozzle.  When mentioning this to our technician and Buderus, they advised against it.  Ready to call my techs one more time to fix this.  If someone knows the best formula for the nozzle reductions and pressure increases so I can tell my technician, I'd be forever grateful....if not, I'm ready to toss it out the window and it's only a year old.

kcopp

Not that there....

are not good oil guys here BUT this is a great question to post @ www.oiltechtalk.com

Lot of oil guys there.

billtwocase

Buderus

Rob O'Brien would have those answers. What burner do you have on it? Nozzle that is currently in it? Combustion and draft results? Pump pressure? I am not a fan of the blue boiler, and have a handful of them in my customer base. They all are running Riello. and no 2 are alike in settings(usually) 

mellowman007

g125

Scott, the g-125 is a great boiler and should run very clean and quiet. The big problem with any new boiler is the set up. Did the tech run a combustion test on the boiler? What is the stack temp?  The G-125 boiler is a non condensing boiler so it is important to have enough heat in the chimney to carry the moisture away before it condenses. If the adjustment is off, the boiler can be damaged.

 The g-125 is very easy boiler to set. 

MY settings can be close to a 300 deg stack 13.8 co2 and very low co...... The best way to tell if the boiler is running well can be the carbon monoxide in the gas. Too high and the  fire can run poorly. Every house is different so the settings have to match the house.

1 (800) buderus Have the tech call they will help.