Tarm 202 Boiler "Bumps" (Explosions)

Tarm 202 boiler "bumps" (explosions)

PostBy: djackman On: Sun Nov 23, 2008 2:48 am

Since firing up this boiler I've had continual problems with occasional "puffbacks", "bumps", "boiler farts" - usually occuring after a decent burn cycle about 3-5 minutes after the thermostatic draft door closed completely.

Tried switching to Blashack nut coal from mixed pea/nut "basement coal"
Leaving an open spot of burning coal to burn off gas
Banking fresh loads, left to right, front to back, middle only, sides only, etc
Limiting the max opening of the draft door
Changed baro damper draft setting
Small load vs full load
Loading on idling fire vs active fire

Nothing helped.

The solution was in front of me the whole time - open the over fire air control half way. Idea came from this thread 1st day with AA130 on line.... then... BOOM! reguarding the removable plug in the viewport of a AA boiler.

It's been almost a week without a "boiler fart" regardless of how, when, or which coal I load. This boiler seems to be very "tight" in that with the draft door closed no air is getting to the fire. 2nd option was a paperclip under the draft door but that really seemed like a patch more than a fix. Dad has the manometer to tweak his oil burner so I can't say for sure but draft does not seem to have been effected - CO alarm not going off, no smell, smoke gets pulled into the over fire air port consistently. Thinking that the over fire air allows coal gas to burned or diluted enough so it doesn't go "boom".

Again looks to be the case with coal that what works for one person doesn't necessarily work for everyone.
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Over fire air control opened half way
Stove/Furnace Make: 1980 vintage Tarm
Stove/Furnace Model: FT22 (aka 202) installed!

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Re: Tarm 202 boiler "bumps" (explosions)

PostBy: Freddy On: Sun Nov 23, 2008 6:45 am

Good fix! I'm glad you got it figured out.

Did it bump any ol' time it felt like it, or only when you opened the door?
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Hot Air Coal Stoker Stove: Reading piece o' junk in the barn (rice)
Coal Size/Type: Pea size, Superior, deep mined

Re: Tarm 202 boiler "bumps" (explosions)

PostBy: djackman On: Sun Nov 23, 2008 2:51 pm

It bumped when the door was closed.

Few times felt like someone fired a 12ga in the basement. Smaller bumps I would just hear a "clang!" when the draft door slammed closed after being blown open.... Actually loosened the mortar where a previous breech in the chimney had been blocked up. Bent one pin on the baro damper (need to switch to a Type M instead of the Type RC)

Inspected the chimney today and it doesn't look like any damage has been done but glad it's fixed!
Stove/Furnace Make: 1980 vintage Tarm
Stove/Furnace Model: FT22 (aka 202) installed!

Re: Tarm 202 boiler "bumps" (explosions)

PostBy: LsFarm On: Sun Nov 23, 2008 4:17 pm

Glad to hear you found a fix for the 'puff backs'. They can be rather 'energetic' at times.. Your Tarm must be a very airtight burner.. That appears to be a pretty large opening in the door vent,, you may have to adjust it down when warm weather is around.. or you may loose too much draft.. but with cold weather it sounds like a good 'fix'.

Your coal must have a fair amount of volitiles.. only fresh anthracite seems to do this.. On the AA boilers there is always fresh coal in the firepot,, but with your Tarm, you should be able to close the vent in the door about an hour or so after you load fresh coal.. if you need to preserve some draft..

Take care,, Greg L

Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

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