oil furnace fuel pump

The whisting noise could be coming from the air intake grill on the side of the burner when its sucking in air. It could be normal, but have a guy come out and take a look, you are better off.

As long as you can check/set pump pressure, obtain the correct single stage or two stage pump, set under and over fire draft, replace oil filter and nozzle, adjust electrode gap, use a smoke pump and adjust CO2 and O2 settings with a digital combustion efficiency analyzer then Id say you can just go ahead and have at it. Bubba

If it whistles while it works, so what? It's not broken is it?

Is the air inlet screen very dirty? If there is a lot of dust occluding the opening it may be making a whistling noise as the required air passes through the remaining small open area.

Changing out the oil pump is straight forward but may not be the problem. have two of these in my home and it takes about an houreach to tear them down, clean and adjust them. Beckett has made these quite easy to service.

Get a copy of the Beckett service manual.