AHS 130 boom, da boom, da boom,boom,boom

I had a phone call from my buddy this morning. His new installation went over a month with no issues & then had a double boom incident a few weeks ago on a warm, damp day. He opened his view port hole, had another big puff back a week later & put a paperclip on the door. After the weather turned real cold he removed the paper clip. Well, it's back on after yesterday! He & the whole family were home. He keeps the hopper very near full, adding one bag a day & two bags each 7th or 8th day if one will fit. His coal is kept outside. It is frozen for sure. It seems if it were too wet it would clump, but he says it's all individual pieces when it's poured in. An hour earlier he had added a bag of coal to the hopper, then the boom! He went running for the cellar and as he's on the stairs, BOOM. 7 or 8 seconds later, another! He can see flame in through the barometric damper door when it happens. Then every 5 or 10 seconds for a minute, BOOM. He said he lost count, but it puffed hard 7 or 8 times before it calmed down. It is very cold here, near zero. A good steady breeze the last few days. His draft is set at .02, goes to .03 while it stokes. Interior chimney about 30 feet tall. It exits the top center of the roof. Of course the first boom blows the clean out door open & then the draft drops to near or at zero. He's burning Kimmel pea coal. Any thoughts to why? Any ideas for a cure? His wife isn't impressed.

Hi Freddy
You didnt give him a bag of the superior coal did you?

Dose he allready have the hole in the view port?

Have you tried your Patened Anki KABOOM view port opener???


Doug

AHS recommends a draft of .04. Previous posts have convinced me that "puff backs" in the AHS are the result of inadequate draft. My own experience with puff backs is fully consistent with the theory that they are caused by inadequate draft.

Also, AHS recommend mounting the barometric damper as far from the unit as possible and as close to the chimney as possible. Is the installation consistent with this recommendation? I ask because of the report that flames can be seen through the damper.

Bob wrote:AHS recommends a draft of .04. Previous posts have convinced me that "puff backs" in the AHS are the result of inadequate draft. My own experience with puff backs is fully consistent with the theory that they are caused by inadequate draft.

Also, AHS recommend mounting the barometric damper as far from the unit as possible and as close to the chimney as possible. Is the installation consistent with this recommendation? I ask because of the report that flames can be seen through the damper.

Thanks Bob,

You hit the nail on the head. .04 all day long.

The pipe from boiler to chimney is about 10' long. Baro is at the chimney. We'll see about getting the draft up.

I remarked "So flames came out the baro?" He said none came out to notice, but he could see flame in the baro.

It is vital to keep a consistent .04 in the off-cycle. Obviously the boiler will take care of itself during run, but when it is idle, the gases must be pulled off. Otherwise, coal-gas ignition a.ka. "puff-backs" will occur.

I would suspect BEANS in the coal.

What size pipe is he running to the chimney 5"or 6"?

Beans! He was in Mexico this summer. Hmmmm

5" to the chimney, converts to 6" at the baro. He did the "axeman" trick on the baro. (5" pipe goes partway into baro")

Freddy wrote:Beans! He was in Mexico this summer. Hmmmm

5" to the chimney, converts to 6" at the baro. He did the "axeman" trick on the baro. (5" pipe goes partway into baro")

I was asking because I think the extra velocity in the exhaust from using 5" over 6 " helps . Is the baro close to the boiler or the chimney ? Oh yea is the stove pipe sealed well at the joints not letting it pull extra air into the pipe . I think of it like an exhaust leak on a car if there is a leak you will get poping and backfiring in the exhaust because of the extra oxygen being allowed into the pipe allowing it to ignite there . Dave

The "boom" thing is why I did not get this boiler. The wife would not have been amused......good luck!

Paulie wrote:The "boom" thing is why I did not get this boiler. The wife would not have been amused......good luck!

There are a lot of people that have no trouble what so ever . My AA130 runs no problem no booms . I believe the coal I am burning is Kimmels as well . I don't think the issue is entireily the fault of the boiler more of a setup issue than anything .

Yup, the joints are screwed and sealed with high temp silicone. It's odd, I thought his chimney would suck the eyeballs from passing frogs, but it sure seems he's going to need a draft inducer. Part of installation was to visually check the chimney, it's clean & clear. 30ish feet tall, interior, right out the peak of the roof & 3 or 4 feet above the peak, no trees around to speak of. Just checked for fly ash build up, none. Odd. I think if the boiler were closer to the chimney it might help, but that 10' is slanted up a bit and seems it should be OK. It just couldn't be closer in his circumstance. I guess it's not ours to wonder why, it just needs to be fixed!

Freddy wrote:Yup, the joints are screwed and sealed with high temp silicone. It's odd, I thought his chimney would suck the eyeballs from passing frogs, but it sure seems he's going to need a draft inducer. Part of installation was to visually check the chimney, it's clean & clear.

The lack of draft suggests that the chimney has an opening somewhere that is allowing air to infiltrate.

1. In your original post you mentioned that the cleanout door had been blown open--is it now properly closed and sealed?
2. Is the chimney liner completely intact with no breaks or unsealed liner joints?
3. Is stove pipe to chimney connection fully sealed?
4. Are there any other openings in the chimney such as a second appliance?

Annother possiblility is that there is a lack of make up air available to the boiler. Is there an adequate outside air supply?

Dose he have enough outside fresh air in the boiler room?