no air flow in an Elica eliplane 80.....

[SH]

interesting one this:

I have an Elica Eliplane which is an over the cooker extractor fan.

It has two motors in it.

It is no longer extracting to the outside world so the kitchen steams up when cooking.

There is ducting from the top exhaust port to the outside world.

So I disconnected the ducting from the cooker hood and turned on the power to the fans. there is *no* movement of air at all at the top of the elica eliplane.....

I removed the grease and charcoal filter which is next to the light on the hob side.

Still no movement of air.....

But... The motors are actually spinning and I can actually see the fan blades spinning.

I have shone a torch down from the exhaust duct and I can see no obstruction(s) and I can also see the fan cylinders rotating.

I have also shone a torch up from the underside (above the hob and again I can see no obsteruction and I can see the rotating fan cylinders....

As there is no movement of air the motors are getting rather warm. Co-incidentally I can feel more movement of air on the cooker hob side so its as if it is recirculating air around the hob rather than extracting it through the fan motors.

So when two fan cylinders are rotating and there is no obstruction(s), why is the air not moving?

The design is notable in that it uses cylindrical impellors as shown below:

My only two thoughts left is its either the motors are not moving as fast as they used to be or the blades on teh cylinder impellers are worn?

S.

[Vir Campestris]

Could the impellers be blocked with grease?

Andy

[SH]

all the slats are clear......

[Sn!pe]

[...]

[...]

Can air get into the kitchen to replace that which should be expelled? Our cooker hood extractor made our log-burner smoke into the kitchen unless we left a door or window open.

[Andy Burns]

I wouldn't expect the blades to touch the housing, so shouldn't wear out.

I have a recollection from elsewhere that you are deaf (sorry if I've got that wrong) can a person with good hearing tell that it's running? They're not normally the quietest of appliances ...

[newshound]

Can't see the impellers getting worn. What sometimes happens with squirrel cage motors running on "lubrite" type bearings (this is sintered phosphor bronze that needs to be saturated with mineral oil for maximum effectiveness) is that the bearings dry out and/or become sticky owing to buildup of dust, grease, oxidised oil, etc. It usually reveals itself when the motors stop rather than running slow, but this is one reason the fans might be slow. When you switch it off, they should take several seconds to run down. If they stop immediately, the bearings need attention. (Could also be sick electrics I suppose, but I would certainly rule out bearings first).

[alan_m]

Are both motors turning in the correct direction? If not perhaps the motor fan blowing is fighting te motor fan sucking :)

[Brian Gaff (Sofa]

This may sound daft, but I once had a fan heater where the motor ran in reverse after a few years. That would I imagine not be very efficient, as the centrifugal fans normally have angled or curved blades. Might be time to take the units apart and see if there are obstructions or if these motors can revolve backwards if a capacitor has died. No idea why they would use a reversible motor in the first place though. Brian

[Brian Gaff (Sofa]

Grease and dust. Brian

[Brian Gaff (Sofa]

It gets inside through the centre usually. Brian