Riello overfire air

[mouse2469]

I am new to this forum and would like to say hi and appreciate any help I can get.Is the only way to reduce the overfire air on a riello is to close back on the air band? I am currently firing a 1.50.Did my combustion test.Had -.02 draft, +.06 overfire,12% co2,390 deg net stack temp with 1 on the smoke.Everything seems ok,(I have a Buderus g215) when I open the door to the combustion chamber,it seems that the retention head is getting coked up.I have a brand new nozzle and filters are clean.To me it seems like there is a little backpressure going on.Any help would be appreciated.

[able1]

g 215 what how many sections why dont you post this in oil burners with out knowing the exact boiler is it a 5 section with 1.50 80w if it is it should have a positive0.02in the boiler a 213 -3 pos 0.08 need more info

[mouse2469]

I have a buderus g215-5,using a 1.50 80w nozzle.I know it is a slightly positive boiler.+.02 ofa.I am interested in finding out if there is any way to lower this a little.As far as the oil burner forum,it wont allow me to post.It says private.Is there a way to get access?Thank you

[able1]

is there a barometric damper if so adjust it check flue passages remove the baffles make sure they are clean if you remove them you will lower the pressure but lose efficiency I would set it up for 0 smoke and 12 c02 check pump pressure and make sure head dimension are right

[beenthere]

Oil burners forum, is a pro forum only.

[bobb25]

I don't like Riellos at all, and luckily there aren't too many in my area, but if you have +.06 over fire, that's back pressure. Without seeing it, I would say your boiler is plugged. You need to clean it out completely. Make sure you can see the other end of the cleaning tool you use.

[mouse2469]

Boiler is not plugged at all.Very clean.I am wondering if I move the baffles from position 1,2 to 2,3 if that will make a difference.I'll let you know.

[bobb25]

Sorry, don't know much about Riellos. Most of them in my area are used on Dynatherm boilers, which is a Scotch Marine presurized boiler. The mfg says they use Riello to overcome back pressure. Some mfgs sell the same boiler and say it will work with several different nozzles, but sometimes the larger nozzle will cause back pressure. If you have the burner set up right, then measure the chamber and make sure the nozzle isn't too big. You can try a smaller nozzle, and/or removing the baffles and see what happens.

[able1]

are you a diyer or in the trade if you dont have a combustion tester you should not touch a burner

[able1]

there is no chamber in a buderus boiler and they dont want you to down size the nozzle so you dont condense in the flue you did not say if there is a barometric damper or not check oil presure and turbulator position reillo is a great burner if you are burning with a #1 smoke you need more air is the boiler in a small boiler room or closet

[mouse2469]

Have a barometric damper.Head set at 1.5.Boiler is in basement.the room it is in is 5x7,but it is also open to the air in the crawlspace.I also have a field controls cas-3 for make up combustion air.I am not an oil burner professional.I am in the combustion field.I do have a combustion kit,and have done alot more than some of these so called Buderus pros.I had 1 guy here who basically lowered my air to 2.1.No combustion test.The next week,I opened the door to the combustion chamber and caked with soot.I had cleaned the boiler prior to him coming over.So,Like I said,I have the thing burning fairly decent,it's just the overfire air that is a little high.Thanks for the input.

[big johnson]

CO2 and smoke sound too high. What's your CO at light off and shut down? The combustion chambers on oil fired boilers are touchy buggers. If your CO is high, you may have a problem with flame impingement which will cause your soot problem big time. Check pump pressure at the jet line too.

[able1]

215 5 40-f10 flow rate1.7 gph 238,000 btu input blast tube insertion 3 3/4'' 145 psi pump pressure air band setting 3.25 delavan 1.50 80 w turbolator 1.5 approx stack temp 350 over fire positive0.02 is barometric damper opening or is it closed it say in the specs above settings were established with baffles installed but not when using a riello burner call buderus tech service but there going to want pump pressure 1-800-286-3787

[mouse2469]

Able1,
Just got off the phone with Buderus tech support.We discussed removing baffles.My manual did not have that info about removing the baffles with the Riello,but their website did.He also suggested replacing the 1.50 80W with a 60 or 70 B.He said with the 80,the retention head will get coked up.That was the problem I have been having all along.Hopefully that will help.I will keep you posted on the outcome.Thanks for everyones help.

[bobb25]

You can also measure the size of the chamber to see if you're over fired. Even if there isn't technically a "chamber", it's the area the nozzle fires into. The chart I've used for 30 years says a 120 square inch chamber should have a maximum firing rate of 1.50gph, and a normal firing rate of 1.35gph. If your fuel pump pressure is set at 140 psi, then you need to multiply that by 1.18, which would mean you're firing at 1.77gph.

I've also found that in almost ever case, a solid nozzle will give a cleaner fire, and the heater won't be as dirty the following year. A "W" is a semi-solid (aka all-purpose) nozzle.