Shutdown bang

marty D_2

A friend called me last night and said his burnham/afg
boiler, approx 15yrs old suddenly started making a loud
bang when it shuts down. Otherwise runs fine. Was serviced
a month ago, company too busy to stop back in near future.
I am relatively new to service, told him I would stop by
tomorrow and take a look. Any hints much appreciated. He
said it is very severe and blows soot out the damper. I
was going to start with pump pressure and cutoff.

thanks in advance

Marty in Maine

Weezbo

blows soot now..later it will catch on fire inthe flue....

not all servicemen are created equal when it comes too the employment of the tools god gave them. it isnt really right to send someone off to fix something that isnt within thier repitoire sort to speak. if you go on the run trust nothing about what supposedly has been done...do your own thinking....proceed just like any out of heat call.when you do it right next month they wont be looking for you.

lchmb

agree with weezbo (I think)

I would check everything from scratch. Z dimension, flame retention head, check to see if the boiler was brushed or if it's plugged now. I would check, and probably change the nozzle, checking to make sure the proper nozzle is in there. Check the venting to include the chimney for blockage. Like I said, I would start at the begining. It could be something as simple as the ignition transformer not tightened down. Let us know what you find..:)

Weezbo

) *~/:)

i think thats the right tact to take my self:) going to systems formulating worst case on the way isnt energy efficient....:) not if you want to maintain steady state efficiency in your normal operation:)

Bill Nye_2

I would

> A friend called me last night and said his

> burnham/afg boiler, approx 15yrs old suddenly

> started making a loud bang when it shuts down.

> Otherwise runs fine. Was serviced a month ago,

> company too busy to stop back in near future. I

> am relatively new to service, told him I would

> stop by tomorrow and take a look. Any hints much

> appreciated. He said it is very severe and blows

> soot out the damper. I was going to start with

> pump pressure and cutoff.

>

> thanks in

> advance

>

> Marty in Maine

Bill Nye_2

I would

Check to see if the firomatic valves are open. High pump vacuum could possibly cause bang on shut down.

marty D_2

Huh?

No sure about what the philosophical messages are. I was
not the one who did the previous service, do not even work
for that company. I have 3yrs service experience which I
appreciate still makes me a rookie. I will check to make
sure firomatics are full open and that xformer/ignitor is
sealed correctly and do vacuum test on oil line along with
pump tests. Of course draft at breech and over fire.Any others?? Thanks

Marty

Weezbo

i realize you may not have taken this call.....

how ever is it sop to ask when the last timethey bought fuel oil and had it delivered? be cause not effect. what would water do to the system? thats right....half the information can put a service guy on his can thats why LCHMB and i are saying do what you normally do ,do it right make sure you are thourough and hey your outta there ...it could be this it could be that diagnosing things over the telephone can only go so far...someone needs to go to the site and do thier work ...the barometric damper may have been blown out of the "T" and is over in a corner some place...the trans former might have a control wire shoved under the plate holding it off the deck, the drive coupler could be slipping ...this is slowly becoming obvious that there are a lotta could be's.you just head on over in the truck and fix it ...

Bill Nye_2

No,

I am not trying to be smart or philosophical, I really mean check to see if the valves are open. The pump can pull the oil through even when they are closed.

I would start right at the tank. Drop the filter, see if oil flows out of the tank by gravity. Put it back together and check the pump strainer, see if oil flows by gravity to the pump cover . I guess you can't assume the other guy got it 100% right, but on the other hand you like to think he did.

Give the electrodes a quick visual, check the end cone for carbon [clinkers] fire it up and do a combustion test.

The reason I'm leaning toward a high vacuum thing is , the oil can get a little seperated and a little weird. Check for good clean pump cut off visually and with a pressure gauge in the nozzle line.

I am not doubting your ability. Merry Christmas.

Weezbo

so you went fixed it ...what did you find?

today i made a brief run on a no heat...an electrical wire on the c1 b1 ...i dont have to rebuild the mans entire heat plant:) took time to ramp the boiler back up, mo jo the relay contactor a couple times,test the operation with the limit switch and t stat a couple times...an outta there in 15 -20 mins what did you discover?

marty D_2

Its fixed, but have no idea why

Guys
Thanks for the input and suggestions. I did not take offense to anything by the way, just did not understand the
initial feedback. Well, here it is. Every setting was right
on, combustion ok. Last thing was to oil the 2 oil ports on
the burner motor and the rough shutdown went away, has not
come back. This may be just a coincidence,but I did not change anything else. Checked oil delivery vacuum at the
input to pump first thing and was fine before I rechecked
the filter/strainer/pressure etc. Guess I will never know
for sure on this one unless the motor not having been oiled
for 15yrs could somehow have caused the rough stops.
Thanks again for always being there to assist.

Marty

Bill Nye_2

Marty

You know what? Now that you mention it........ When you service a nozzle or fuel unit, a little bit of air can get trapped in the nozzle assembly piping. Usually goes away after you cycle the burner a few times. This could cause that.

Steamhead

Dry bearings could have caused it

This would make the motor stop quickly instead of "coasting" to a stop, which would make less air available to the flame as it went out.

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marty D_2

Never stop learning

This goes to show that the best part of this trade is
that every day brings a new challenge, and we will never
stop learning something new will we.

thanks again

marty