Riello Buderus starting problem

psd_3

I have a new Buderus G115-34 with a Riello BF5. The unit is chimney vented and is taking in external combustion air.

In about 1 out of 5 starts the unit will continue to rumble through the entire cycle (5 minutes) and will emit a real sooty exhaust smell from the draft regulator. During a bad burn, I do not hear the normal draft rush through my stack pipe (terminating on 30' of 5" SS liner with rain cap at top). Occasionally the unit will even loose flame and will retry. The other starts are crisp, the the run is smooth and normal and there is a strong draft sound.

The techs from Riello and Buderus looked the entire system over today and didn't find anything but perhaps the gap in the electrodes a bit too tight for their liking. All parameters were measured and were right on at operating temperature:

Stact Temp 340F,
O2 7.2%,
CO 55 ppm,
CO2 10.3%,
Draft -.03 inH2o

Although some suggestions have questioned the use a draft regulator with this system, the Riello and Buderus folks strongly require it. In any case, operation with it blocked does not appear to correct the issue.

I'm not an oil/boiler pro, but it almost seems that taking in cold outside air during the pre-purge cycle is sometimes creating a cold air plug inside the passes of the boiler and then the burner is having difficulty displacing it?? Although, the issue does not seem to be sensitive to environmental conditions. Warm outside, cold outside, boiler hot, boiler cold all seem to be about the same wrt to likely hood of the issue.

More folks will be visiting tomorrow -

Perhaps a bad nozzle, sticky oil solenoid, intermittent pump??

Any advice, similar experiences, suggestions?

Robert O'Connor_6

Did

Could be all of the above .
I would start with oil pressure and delivery systemcoupling etc.

C02 seems a bit low.Riello's reallly like zero draft over the fire, Is their a draft regulator?

I would be intersted to know CO immediately upon start up . That will tell you alot

Generally this combo is trouble free if set to spec.

Regards,

Robert

psd_3

Coupling?

I don't think they did.
What's the issue here ...
Is there something going on in this area with Riellos?

SteveB

Riello

I have installed many Buderus/Riello combinations and all have worked very well. I would try a Delevan 60 degree W nozzle. We use those exclusively on our Riellos with excellent results. Also your CO2 number is much too low, you should be up around 13%. You have too much air to the fire and are blowing the flame off the retention ring.

psd_3

Nozzle

Am using a Delevan .85 60 W @ 145 psi (stock for the BF5)
The Riello techs started with CO2 around 12% and then
adjusted air to get 0 smoke, they were content with CO2 at 10.3% when done. Go figure ... I'm only the dumb home owner

Phifer

Buderus-Riello

Call the people at Rood Utilities in Auburn Ny. They have the longest experience in the usa with both Buderus {1980}
and Riello {1977} They did the original burner testing with
Buderus.

[Deleted User]

oil temp..

is the oil supply from a outside or cold source... i have had problems with the bf when boiler shuts off then restarts with cold air in intake and cold oil and not much refractory material burner gave a rumble,, corrected problems by using tiger loop,,,to heat oil,bumped pressure up to 160 psi and added some length to air intake pipe to help preheat air good luck.. mike

Ken_15

Is there a carpet in the chamber?

psd_3

More changes

The story continues -
Nozzle changed to Delevan .85 60 B
Blast tube inserted 2" deeper (at least 10" inserted now)
Turbulator set to ~1.5 down from 3
Air Setting at ~4.5
CO2 increased to 12.5% with 0 smoke
Ran better hot, but continued to cut out when starting cold
(cycled on-off 5-6 times before catching and then rumbled)

Pump pressure raised to 170 PSI
CO2 raised to 13% with 0 smoke
CO at 18ppm
seems somewhat better ... time will tell

Riello BF5 setup seems very sensitive with Buderus ... thought that this was a plug-and-play pairing??

DaveGateway

Bill, you might want to try a post at Oil Tech Talk There is a lot of knowledge there about oil guns. Good luck