RBI dominator boiler trouble

[mechforlife]

model#bd1050 RBI having trouble with it starting, due to air balance I believe, everything is set correctly, but it seems to blow itself out after flame proof on ignition, main burners come on and it blows out sounds like foo foo foo and retry. even the barametric vent damper slams and rocks back and forth. inlet filter is clean, but when I remove the access door it fires right up beautifully.

[saylor240]

is the vent cap on?

[mechforlife]

IS THE VENT CAP ON, HUH? ONCE AGAIN THE NAVY IS NO HELP AT ALL. LOL

[Moose]

So what happens when you remove the access door? - Does it draw air, or do you have backpressure @ the door? What is your fuel?

[nyrb]

Assuming that you have the differential air pressure set right, I'd be taking a close look at the heat exchanger to see if it's plugged up and causing excessive back pressure. I've seen a number of these style boilers with fouled heat exchangers that have destroyed the burners as well.

[saylor240]

Navy?.....at a air force base?.....funny. anyway it was Keep it simple question. i have seen boiler do the same thing, because it had either improper vent cap or no vent cap. and you said damper slams back and forth, was legit question....

[mechforlife]

lol sorry saylor240 I couldnt resist, anyway ya, thats what I'm thinking a pluged up heat exchanger, low fire air pressure delta is .68 set by installers and high fire is 1.0"wc but now I'm getting a low air fault. plus a failed or fauls start, like a flame blow out. and like I said in the last post, when I remove the upper access panel it starts and runs perfectly. I relly dont want to remove the heat exchanger just to clean it. thanks everyone.

[saylor240]

NO Problem man, yes my last name is saylor and work for the air force, one time i had on a badge that said my name Saylor, and a guy walks up to me while were out smoking and says " navy guy huh" funny, anyway. cause your saying that when you remove that upper access i am still leaning towards a flue issue. i have seen a nest in a flue cause all kinds of little headaches and quirks.

[mechforlife]

I've had the flue off to inspect it, its completely clean no build up and know obstruction. and for moose when I remove the door it draws air in.

[saylor240]

Got this off there website, seeing how you checked every thing else looks like its the pressure switch setting or failed pressure switch, you could try and jump it out and see if it stays on. its probably n/o switch so let it kick on then jump it.


Gas Flow Shuts Off During Low air (blocked flue/inlet) • If condition exists,check inlet,
Operation (Blowers Remain On) condition flue, chimney for blockage
• Check combustion air/ventilation
openings in space
• Check inlet air filter, clean/replace
as necessary
• Check pressure switch for correct
setting

[mechforlife]

this might be a late response, but yes. it was both the right and left low fire pressure switches.