Weil Mclain D7 combustion roll out

citywide

Getting roll out at the combustion chamber. This unit has ribbon burners at I'm lead to belive that this may be my problem. Pulled and brushed the burners in and out Disassembled and brushed boilers' sections and inspect chimmney for obstructions clear 20' shot straight up no probs there only unit vented on 6" stack. Unit has a vertical draft diverter. Primary shutters fully open plenty of air in mechanical room. gas press at manifold 3.5 Was told to eliminate the diverter but I don't belive that's the answer. Thinking the ribbons may need to be soaked and hit with some compressed air any thoughts? Forgot to mention heavy orange in flame seems to be splashing off the crown

Ed_26

roll-out

Orange is usually a sign of dust/rust/dirt in flame. Roll-out could be lack of draft or gas valve issue. Has the gas valve been changed? If not the proper opening sequence, could be "dumping" too much gas-too fast to the burners.
Check the specs if you can. Also - lighter strips dirty or pinched - check the gaps.

Ed_26

roll-out

Forgot something - some boilers have draft hoods with bi-mettallic 'dampers' in them. They are supposed to open when the heat hits them.

citywide

manifold pressure

man press ok @3.5 per specs. By lighter strips do you mean the cross lighter slits they're ok I have no probs lighting off. It seems to be an incomplete combustion problem that may be because the ribbons have some dirt in there I'm not seeing. This possible? Thought of cleaning with a solution.Hoping this will eliminate the incomplete combustion problem. As for the venting issue Thought it was occuring on cold start but still spilling after warm up As I said it'd the only appliance vented 20' of 6" I'll check pressures again tommorrow with another man gauge Using a robin air that might be giving false reading.

citywide

Not this one

It's got a vertical draft diverter on it

Joe_8

Possibile to show pic of the burners. I ran into aproblem with a weil. the burners were cylintrical and had a venturi in them. got full of sheetrock dust. tried air compressor and brushes they would run fine for a week then start to foul again had to buynew burners

citywide

interesting

I'll get pics tommorrow. Where can I send them?

citywide

Cleaning the burners

any reccomendations on how to clean the burners Talked to a rep and he says the ribbons can be disassembled from the cast housings Seems like a can a worms I don't want to open especially knowing there's no replacement burners available

Timco

Mechanical room negative pressure, or too high gas % to ignite properly?? Sounds like the gas is following a path to the right mix...which may not be in the desired direction. If a vent problem, you would see the flame flutter or being pushed out, as opposed to crawling out.

T

citywide

no neg press

I opened a nearby window to insure that it wasn't under neg pressure. Thanks for the input. I'll have to get another manifold reading tomorrow with a dif manometer. I check back with results Any thoughts on eliminating the vertical draft diverter to help pull combustion up and out. Seems like I recall equipment having to have a diverter installed per mfg specs but can't remember why.

Jim Davis

Did you get a draft reading? This is the only true way to determine room pressure. If you have draft you have air. If you have draft, take some cardboard and block off half to 2/3rds of the drafthood and see if this makes a difference. Would be nice if you had a CO analyzer and could list CO readings after 1 minute, 2 minutes, 3 minutes.

Timco

Jim Davis or Mark Eatherton would be the ones to ask on the subject of improving on mfg design. You could wrap foil around the current draft hood and see if it increases your draft...

Tim

citywide

strong pull at diverter

Pulling strong at the diverter but drafting well on the boiler side .Is it posible it's pulling too much combustion air from room and impeding the draft of the combustion chamber because the chimmney's maxed out.Van got hit 2 weeks ago Lost a beautiful bacharach analyzer.Only had it a month and was just getting familar with it. No stack temp readings,co,or draft readings. Thought about a barometric 2 way draft control with roll out but I'd be putting it in blind.I'll try to portion off some of the diverter tomorrow.If it helps can I leave it that way?

Timco

Without a CA, you are still blind..barometric or blocked hood. I would start at the beginning and re-check my gas pipe sizes from the meter, clock the meter, check manifold pressure (if possible w/o the tester), do the math on the combustion / makeup air and re-do the math on the vent/liner size first...especially without the ability to check the flue gas.

Tim