Beckett burner keeps cycling
#1
03-08-08, 06:52 AM
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Beckett burner keeps cycling
Hi all, I have a DMO oil furnace with a Beckett burner and a Honeywell 8184 control. The burner comes on, the fan starts and after a minute or so the burner shuts off, the fan is still running. A minute later the burner comes on again runs for a minute and shuts off again. This repeats untill the house is warm enough to shut the thermostat off. Is it possible the honeywell is the problem or something else. Any ideas would be appreciated.
#2
03-08-08, 07:21 AM
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Possible reasons:
* the main blower is set to too low a speed (check the split)
* improper t-stat anticipator setting (if electromechanical)
* oversized furnace (unlikely if this is a recent problem)
* limit setpoint too low
* fan-ON delay temperature setpoint too high
* air filter extremely dirty (replace)
* insufficient return (registers shut closed)
* too large a nozzle (was this unit serviced recently?)
Not likely that the primary control (8184) is the source of the problem b/c it has a "manual reset" type switch. If it trips you'd have to manually push the reset button else the burner would not come back ON at all.
* the main blower is set to too low a speed (check the split)
* improper t-stat anticipator setting (if electromechanical)
* oversized furnace (unlikely if this is a recent problem)
* limit setpoint too low
* fan-ON delay temperature setpoint too high
* air filter extremely dirty (replace)
* insufficient return (registers shut closed)
* too large a nozzle (was this unit serviced recently?)
Not likely that the primary control (8184) is the source of the problem b/c it has a "manual reset" type switch. If it trips you'd have to manually push the reset button else the burner would not come back ON at all.
#4
03-09-08, 06:09 AM
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Beckett burner
I had the unit cleaned about a month ago, the problem started about a week or so ago Pflor, returns and registers are clear, filter is clean. Yes Grady it has a fan/limit control.
#5
03-09-08, 06:53 AM
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What are the current settings on the fan-limit control?
Best case scenario, this could be the source of the problem.
It is possible that b/c of your local weather the unit was not being called to run too often recently and you noticed this problem (as you indicate) just about a week ago, but may have been there since the last service call was performed.
Do you have the bill of work stating what was done (service/maintenance) when your unit was cleaned a month ago? if so, please report.
Also...Was the nozzle replaced? check the nameplate for mfr recommended nozzle (GPH, angle & spray pattern) and compare to what is now installed (you'll need to remove the nozzle/electrode assembly for this). The nozzle is one of the items that should be replaced on a std. maintenance call. I'd double check that is not an oversized one installed there now.
Where the t-stat settings adjusted on that last service call? and which type of t-stat do you have (pls give mfr & m/n)?
Finally, how old is this furnace? is it possible that the motor of the burner is shutting off on overload?
You need to babysit this unit (get a chair in front of it and stay there to see what makes it happen)...to see which component triggers the problem. Is it the burner motor the one that stops first? the house blower? Does the fan-limit dial spins itself around until it turns off the burner?
Best case scenario, this could be the source of the problem.
It is possible that b/c of your local weather the unit was not being called to run too often recently and you noticed this problem (as you indicate) just about a week ago, but may have been there since the last service call was performed.
Do you have the bill of work stating what was done (service/maintenance) when your unit was cleaned a month ago? if so, please report.
Also...Was the nozzle replaced? check the nameplate for mfr recommended nozzle (GPH, angle & spray pattern) and compare to what is now installed (you'll need to remove the nozzle/electrode assembly for this). The nozzle is one of the items that should be replaced on a std. maintenance call. I'd double check that is not an oversized one installed there now.
Where the t-stat settings adjusted on that last service call? and which type of t-stat do you have (pls give mfr & m/n)?
Finally, how old is this furnace? is it possible that the motor of the burner is shutting off on overload?
You need to babysit this unit (get a chair in front of it and stay there to see what makes it happen)...to see which component triggers the problem. Is it the burner motor the one that stops first? the house blower? Does the fan-limit dial spins itself around until it turns off the burner?
#6
03-12-08, 02:59 PM
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Beckett burner
Thanks for all your ideas guys, turns out for some reason the guy that serviced the furnace must have changed the limits on the control, it was set to 150 degrees, I spoke to an old oil guy and he told me it should be set around 185-195. Changed the setting today and it works fine, no more cycling.
Thanks again for pointing me in the right direction!
Thanks again for pointing me in the right direction!
