Readjust oil burner when changing blower wheel in power vent?

[Eric]

Here's a good HVAC question I haven't seen here before...

In my house I've got two oil burners (hot air furnace and separate water heater) vented by a Field SWG power venter. At the ripe old age of 8 years, the blower wheel (squirrel cage) in the power vent rusted out and actually lost a blade.

So I ordered a new wheel and installed it. The new wheel is stainless and is designed very slightly differently from the old one, but is definitely the correct part and is intended to replace the one that was in there. I did *not* touch any adjustments, just disassembled the venter enough to replace the wheel, replaced said wheel, and reassembled it.

So my question, finally: it seems like we're getting a lot more "burning oil" odor in the house than we were before. I can easily believe this could just be the wind direction, but I wonder if changing that wheel might have changed the draft on the oil burners enough that they're now not burning cleanly.

Anyone ever dealt with this before? Should I get a tech out to readjust the burners?

Eric Law Wilmington, MA

[George]

heater) vented by a Field SWG power venter. At the

rusted out and actually lost a blade.

designed very slightly differently from the old

that was in there. I did *not* touch any

replaced said wheel, and reassembled it.

odor in the house than we were before. I can

that wheel might have changed the draft on the

If the wheel is designed differently as you described it certainly is reasonable to think its performance has changed requiring a readjustment.

[RBM]

Seems to me, a question you might want to direct toward the techs at Fields controls. The blower's controls won't allow the burner to fire unless a sufficient air flow is established, so I can't imagine the smell coming from inside the house

[Mark]

heater) vented by a Field SWG power venter. At the

rusted out and actually lost a blade.

designed very slightly differently from the old

that was in there. I did *not* touch any

replaced said wheel, and reassembled it.

odor in the house than we were before. I can

that wheel might have changed the draft on the

are you sure the new wheel is installed and of the correct design such that it is pushing the air in the correct direction and not in the opposite direction.

Someone that has more hands on experience than I do can answer this question...if you put a squirrl cage blower wheel onto the motor shaft backwards, will the airflow be reveresed?

Mark

[RBM]

The burner won't fire!!

[EL]

No, it's definitely flowing considerable air in the correct direction. The fumes are being taken outside the house, and it's generating enough draft to operate the safety switch and allow the burners to run.

I'm just wondering if the airflow was a few percent different thru the venter, how much would it affect the burners? I'd think the draft regulators (there's one at the output of each appliance) would take care of it to an extent.

Eric

[EL]

That's a great idea!

I didn't think of it since there's nothing on their website about replacing the squirrel cage separately. They want you to replace the entire motor assembly (which includes the blower wheel).

I downloaded & read the motor-replacement procedure, it doesn't say anything about readjusting the burner(s). So maybe there's my answer!

Eric

[Don Young]

Reversing the blower wheel will not cause the air flow to reverse but it can effect the amount of flow.

Don Young

[Stormin Mormon]

Shouldn't affect the burners. The burners use air which is provided from a fan in the burner gun, which is a whole different air flow than the hot air to the building.

[Don Young]

I believe the OP indicated that he was talking about a draft blower, not a hot air circulating blower.

Don Young .