Draft Control flap slams when Buderus oil boiler shuts off

cckriss

https://streamable.com/byhl4r

Here is a video of what happens.

The Buderus boiler was installed a few years ago, this never happened. A couple of months ago, i had the exhaust liner replaced.

What is happening? It’s so loud.

HVACNUT

What size liner was installed?
What model Buderus? The G115 has a 5 inch flue while the G215 uses 6 inch.
It's not abnormal for the regulator to move when the burner shuts off, but I don't see it budge during the run. A draft test must be done, and the regulator adjusted. With either the G115 or G215, Buderus specs 0 to slightly positive draft over fire, and -.02 breach. Smoke and combustion tests should be done as well. Has it been serviced since the installation?

cckriss

HVACNUT said:

What size liner was installed?
What model Buderus? The G115 has a 5 inch flue while the G215 uses 6 inch.
It's not abnormal for the regulator to move when the burner shuts off, but I don't see it budge during the run. A draft test must be done, and the regulator adjusted. With either the G115 or G215, Buderus specs 0 to slightly positive draft over fire, and -.02 breach. Smoke and combustion tests should be done as well. Has it been serviced since the installation?

It is G115 with 5”. Before the liner, it was -.05 as measured by the boiler installers. An energy auditor measured it at -.01 and said it was not enough and i should call a chimney company. The chimney company said the original flue tiles had alot of yellow deposits and it should be re-lined. I dont know what they measured.

I used to occasionally smell very very slight diesel fumes near the boiler when it first starts up. After re-lining, i no longer smell anything.

The boiler has been serviced once, before re-lining.

HVACNUT

cckriss said:

HVACNUT said:

What size liner was installed?
What model Buderus? The G115 has a 5 inch flue while the G215 uses 6 inch.
It's not abnormal for the regulator to move when the burner shuts off, but I don't see it budge during the run. A draft test must be done, and the regulator adjusted. With either the G115 or G215, Buderus specs 0 to slightly positive draft over fire, and -.02 breach. Smoke and combustion tests should be done as well. Has it been serviced since the installation?

It is G115 with 5”. Before the liner, it was -.05 as measured by the boiler installers. An energy auditor measured it at -.01 and said it was not enough and i should call a chimney company. The chimney company said the original flue tiles had alot of yellow deposits and it should be re-lined. I dont know what they measured.

I used to occasionally smell very very slight diesel fumes near the boiler when it first starts up. After re-lining, i no longer smell anything.

The boiler has been serviced once, before re-lining.

Have it tested again. Combustion, smoke, draft.

EBEBRATT-Ed

When the burner shuts off the flame collapses and causes the draft to change instantly. This is common. If the burner does not have a post purge perhaps that can be added it would quiet the shutdown

cckriss

EBEBRATT-Ed said:

When the burner shuts off the flame collapses and causes the draft to change instantly. This is common. If the burner does not have a post purge perhaps that can be added it would quiet the shutdown

Is this something I can DIY? If not, do I call a plumber? HVAC guy? Chimney guy?

Thanks

HVACNUT

cckriss said:

When the burner shuts off the flame collapses and causes the draft to change instantly. This is common. If the burner does not have a post purge perhaps that can be added it would quiet the shutdown

Is this something I can DIY? If not, do I call a plumber? HVAC guy? Chimney guy? Thanks

You call an oil burner tech.
What burner? A Beckett or Carlin needs to have a primary capable of post purge. If it's a Riello, it needs a post purge timer module. 

cckriss

It's a Buderus G115. Oh I believe it's a Reillo 40.

HVACNUT said:

cckriss said:

EBEBRATT-Ed said:

When the burner shuts off the flame collapses and causes the draft to change instantly. This is common. If the burner does not have a post purge perhaps that can be added it would quiet the shutdown

Is this something I can DIY? If not, do I call a plumber? HVAC guy? Chimney guy?

Thanks

You call an oil burner tech.
What burner? A Beckett or Carlin needs to have a primary capable of post purge. If it's a Riello, it needs a post purge timer module. 

Big Ed_4

Sounds correct to me with your Buderus and a perfect sized liner ..

cckriss

Big Ed_4 said:

Sounds correct to me with your Buderus and a perfect sized liner ..

It's really loud. I can hear it from the 2nd floor.

Big Ed_4

Your Buderus can be fired direct vent . It serves no purpose on your boiler but it is code... A missed placed screw could lock it in ....

HVACNUT

Big Ed_4 said:

Your Buderus can be fired direct vent . It serves no purpose on your boiler but it is code... A missed placed screw could lock it in ....

What serves no purpose, the draft regulator? If draft is greater than -.02 at the breech, how do you "regulate" that?
And direct venting would require a balanced flue with the BF Riello, not the F3 or F5 40 Series.

Big Ed_4

You are right , ...The banging of the damper , the static pressure is high or location on damper