Carbon build up on Reillo turbulator

Ed_69

I have Buderus G115/28 with Reillo BF 3 direct vented with fields 4" concentric vent.

The problem I have is carbon builds up on the turbulator to point where flame sensor cannot see flame. It happens over a few weeks and there is a small cup worth on chamber floor. The burner is set up with zero smoke and there is no soot build up, only the carbon on head.

Burner came out of box set up for G115/21 with air set high (.50 x 80 W nozzle, 5.5 air, 0.0 turb). I intended underfiring boiler anyway so set up burner adjusting air down. Ran OK except for carbon build up on head.

I called Reillo tech support who said setup was fine and problem was probably oil related, they suggested increasing pressure and a tiger loop. Pressure increased from145psi to 155psi and tiger loop installed but carbon still a problem.

I heard that cold air supply may be problem so mixing tee installed in air intake line and several mixes tried from 100% outside to 100% inside air (with extra ventilation to ensure indoor supply). Again carbon still a problem.

I have also tried new nozzles, turb 3.0 (to allow more air to bypass head) and buderus spec nozzle size for this boiler 0.65x60W. Air set between 4 and 5.5 to set up burner for zero smoke.

It is now set up 0.50x80W, air 5, turb 0, pressure 145 psi. Head requires cleaning every few weeks.

The oil tank is indoor and with tiger loop the oil is warm.  The burner is not cycling, about 10 starts a day.

Anyone got any suggestions other than clean head every week?

Thanks 

Robert O'Brien

DV

requires the intake and exhaust be in the same pressure zone,you can't use air from anywhere other than than the designed intake. How long is the the post purge?

RobbieDo

CO

What are your CO readings, what is the stack temp?

Ed_69

re

DV: Intake and exhaust are both same pressure zone (outside). The mix was "experiment" after reading online of similar problem resolved this way. System is back to outside only.  Start purge is 12 seconds, post purge is 2 min 15 seconds.

CO: Stack temp is ~450 F (net ~400 F). Air adjusted for zero smoke but no CO reading. I know I need to get CO tester to set up my boiler accurately but it has been run with air adjusted between 4 to 5.5 giving zero smoke to traces of smoke and carbon problem did not seem to be effected on range. Working on a CO tester so hopefully I'll get CO reading soon to eliminate it as possible factor.

Thanks for comments

icesailor

"0" Smoke:

How do you know you have "0" smoke without a smoke tester? What's' your draft?

It would be nice to have an electronic combustion analyzer but you could start with a Bachrach wet bulb test CO2 test kit and be farther ahead than you are now. If you don't even know what the CO2 is, knowing the CO isn't much help at this point.

At least with that kit, you get a decent draft gauge, a decent thermometer, a decent smoke tester and a wet bulb CO2 analyzer that is as accurate or more than a digital analyzer. It just doesn't do CO or give you a print out. But you are not at that point anyway. I also find that it takes a lot of experience to interpret the results. Something you can not do testing once or twice a year on the same piece of equipment.

Ed_69

re

I have a Bachrach test kit but need more fyrite for CO2 tester.

Smoke test was done with Bachrach smoke tester and stack temp from Bachrach thermometer.

As for draft, the system is Direct Vent with positive draft.

Yes I need to get some fyrite and get CO2 tester working again but as I only use it on my own boiler I had been holding off. 

icesailor

Firerite fluid:

The fluid is good for over 400 testings. Did you loose the fluid or do you just think it is bad? It may not be. Even if it is low, you can add water to bring it back. In the Firerite instructions, there are instructions on how to tell if the fluid is bad. If you go to FW Webb, they have the repair kits in stock. I just rebuilt mine.

But the fact that the fluid is low in the tester isn't a problem as long as you don't need to add a lot of water to bring it back. Like a couple of large tablespoons. Put a very small amount on the top and push the plunger down. Be very careful to not add too much. Invert the cylinder a couple of times like you are doing a test. Hold upright and push the plunger down to see where it is now. Adjust the scale.

My fluid before I changed it the last time must have been over 10 years and it was still good. It was the valves that were going bad. Webb has complete repair kits for them. 

Ironman

Cannot Under Fire Buderus...

You can not under fire a Buderus oil boiler. They preach this constantly in all their oil schools. Your current settings don't match what is spec'd for a 21 or 28 completely.



I'd recommend that you set it back up according to 28 spec's and then increase your pump pressure if the problem continues. As already stated: you must do combustion analysis with every adjustment.