Unit spotters for about 18 seconds on start up then run smooth

CometoJesus

Hey guys I just did a cleaning and the customer was complaining that the unit is making noise on start up, during the cleanings I changed the nozzle filter and strainer, the original filter was a micro filter I replaced with a felt. I have a slightly bigger nozzle in there(was a .65 now a 7.5) but did a efficiency test and seemed fine the customer also said the unit would make the noise more consistent when the door to the furnace was off, I was thinking maybe its pulling in a little air or ignition a little weak? Just wanted to pick your brains before I go back

CometoJesus

I meant .75 not 7.5

HVACNUT

What were the numbers on the combustion test? Draft? Smoke? Did you test with the door open or closed?

EdTheHeaterMan

What burner are you having this problem on? Beckett, Carlin, Wayne??? Model number?
Do you have a high pressure line valve or clean cut pump?
What is your oil pressure?
A valve with a pre-purge control or a delay oil valve might help.
Perhaps the previous tech had a similar problem and was able to correct it with a smaller nozzle at a higher pressure.

Dropping from seven and a half gallons per hour to .65 is a rather large drop though LOL

STEVEusaPA

What’s wrong with you people? He said 'it seemed fine', lol
We need more info. Make, model, pump pressure, etc.

EdTheHeaterMan

STEVEusaPA said:

What’s wrong with you people? He said 'it seemed fine', lol
We need more info. Make, model, pump pressure, etc.

What was the make and model of the last sputtering oil burner you worked on Steve? Give @CometoJesus a break, It is a customer's heater... That information may not be available until Jesus returns... To the customers home, not from the dead

But I can think of several things, Like if it is a 2 pipe fuel line and the filter gasket did not seat correctly, It may take a few seconds to clear all the air from the oil line.

To know what is happening, you will need a pressure gauge on the High Pressure line port of the pump, A vacuum gauge on he suction side of the pump. A draft gauge in flame the view port or "Over Fire" location and a good understanding of what is supposed to happen on start up of the burner.

It might be something as simple as forgetting to tighten the screw to secure the air adjustment setting.

And please don't take offense to out sarcasm @CometoJesus. Sometimes... We are all just pushing each other's buttons. Steve is one of the best oil heat guys here. (but Not THEE Best).