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auto flue dampers for oil burners?

hi there,

as i understand it, motorized flue dampers are not made for oil burners any more. is this because they're not considered worth any real savings (for my old boiler)? or that they are too risky? i see that honeywell & effikal do make these units for gas boilers. is there any reason why the gas versions could not be easily wired up for use on an oil burner?




  • Weezbo
    Weezbo Member Posts: 6,232
    there is indeed one...

    Effikal had motorized dampers ,and exhibited them on the east coast about3 years ago...i ordered 3 6's 3 7's and 3 8" and have yet to see one other than in theNEWS a mechanical rag worth perusing from time to time:)
  • Steamhead
    Steamhead Member Posts: 16,719
    The standby loss

    on an oil-fired boiler is much less than on an atmospheric gas-fired one. The reason for this is the gas boiler is open all the way across the bottom of the sections (where the burners are) but the oil-fired one can only admit air to the firing area thru a 4-inch blast tube, which on a flame-retention burner is restricted by static disks and the retention head, inlet air restrictors and fan wheel.

    So there has been much less demand for dampers on oil-fired boilers than on gas ones. The only brand of oil-fired damper I knew of was Flair, and they went out of business a few years ago.

    That said, a damper on an oil-fired boiler can still make a difference, especially if the chimney was built powerfully enough for a coal boiler. I have an old Flair on mine, and on a mild day when the boiler runs a short while in the morning and is then off all day, there is still some heat left in the boiler when evening comes.

    Trying to use a gas-rated damper on oil would not be a good idea. Although a high-efficiency oil burner will burn without smoke or soot (practiaclly as clean as gas) if something goes wrong it can cause the damper to stick. This would result in a no-heat situation at best, and at worst would cause combustion products to be released into the house.

    Wait for someone to come out with a damper that's rated for oil.

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  • Weezbo
    Weezbo Member Posts: 6,232
    the last word was,EffiKal wants the boiler type and firing

    rate...the 24v auto damper that i saw was looking a whole lot like a zone damper for forced air. Except ;That it had a ul listing for Oil Fired appliances! :) So naturally i like that idea :) right now its close to 30 below zero :) and belive me even with positive shut off on the riello i still like the oil damper idea...what ever :) i feel so bad these days for having installed so many energy uneffiecent burners :( oh they were adjusted to be the best they could be buh really probably close to 30 % of the heat just shoots up the stack when the boilers off without positive shut off at the burners air band (combustion air inlet.). the stack is a trickier deal ,soot is a bad deal,too low a stack temp might cause rather than solve problems,fault retry /excercising ,fail open ,temp range indicator might all be good things to have on one however it must have cost the company a small fortune forr the certifications on the valve funny thing they never made it here...Maybe these too got ambushed in or along the way to me:)
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    I think....

    One of the biggest hinderences to installing a damper in an oil flue at this point is the newer controls. It's definately NOT like the old days when a stack scrubber/heater could be put in the line and work with 600°+ stack temps.Hopefully for most of us, those beasts are gone! The newer controls and the timing factors involved are one thing that work against installing one. (I know things can be adjusted accordingly, but will it save anything in the long run? For a few years, even Riello did away with their inlet shutoff/hydraulic ram set-up and replaced it with a fixed air adjuster. They're back with a new electric model but the jury is still out on that too.)

    I think that the drawback to setting a damper in the flue would also be the cooling of the flue itself, in the case of an outside chimney especially. Most new burners, being positive pressure units, will overcome a draft loss with proper maintenance and testing to make sure the fire will not produce any heat exchanger clogging desbris. However, we all know that it ain't always the way it happens.

    One other thing for your consideration...What is going to happen to an oil burner nozzle after a particularly long run, when the boiler/furnace shuts down? Will the lack of flow through the heat exchanger beat on the end cone and make the nozzle deform, and thus spray a bit funny after a while? We used to see this alot when the dampers were installed on boilers with firebrick chambers.(think Delevan....where a stainless insert is pressed into a brass body and both metals contract at different rates).

    As long as the HEAT is being put into the right places in the home and the hot water is sufficient, with proper insulation and sizing of the boiler (for the home) , it shouldn't make that much of a difference.

    This is JMHO. I've been an oil technician for 20 years, and saw the advent of "cold start" boilers and the effect they had on the service end of the business.BTW....That wasn't pretty! One of the biggest advocates even drew back after it was taken as "gospel", and now advocates at least some maintenance temp. as a deterent to clogging a boiler. There are 2 sides to every decision, the action, and the REACTION. The costs to the customer in the longterm, become the deciding factor in my book. Will they save enough in fuel to pay for the extra cost of parts and services required? Hint...Haven't seen it happen yet! Chris
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