Had to replace another antique switch with a shiny new 2477D V.45 dimmer in the the Master bathroom. A long, long time ago, I wrote programs for each bathroom to turn the fan off after a while.

Just went in to the Admin Console to check/adjust the program for the new switch. One thing is bugging me now. Here's a sample from one of the other working programs:

Guest Bath Fan AutoOff - [ID 002E][Parent 0001]

If

'Guest Bath Light' is switched Off

And 'Guest Bath Fan' Status is On

Then

Wait 30 minutes and 30 seconds

Set 'Guest Bath Fan' Off

Run Program 'Debug - Guest Bath Fan Auto Off' (If)

Else

- No Actions - (To add one, press 'Action')

Master Bath Fan AutoOff - [ID 0018][Parent 0001]

If

'Bathroom Light' is switched Off

And 'Bathroom Fan' Status is 100%

Then

Wait 30 minutes and 30 seconds

Set 'Bathroom Fan' Off

Run Program 'Debug - Master Bath Fan Auto Off' (If)

Else

- No Actions - (To add one, press 'Action')

I can't get the statement "Fan' Status is 100%" to say " Status is On" as with the other 2 programs. Again, I'm really rusty at programming and surely missing something obvious!

Thanks!

I haven't used insteon or isy in a while but if memory serves correct, you're getting 100% instead of on/off due to it being a dimmer vs a relay.

Yes, since you installed a 2477D you're getting the dimmer version of full on. Having a fan on a dimmer isn't ideal, and might damage the switch.

18 hours ago, lilyoyo said:

I haven't used insteon or isy in a while but if memory serves correct, you're getting 100% instead of on/off due to it being a dimmer vs a relay.

Thanks, that makes perfect sense.

8 hours ago, Guy Lavoie said:

Yes, since you installed a 2477D you're getting the dimmer version of full on. Having a fan on a dimmer isn't ideal, and might damage the switch.

Oh wow, I had no idea! When I was ordering the new switch, I just went ahead and ordered two of them, never thinking there could be any issues. Is anyone aware of any actual issues with using a dimmer switch on a bathroom fan?

2 minutes ago, johnmsch said:

Oh wow, I had no idea! When I was ordering the new switch, I just went ahead and ordered two of them, never thinking there could be any issues. Is anyone aware of any actual issues with using a dimmer switch on a bathroom fan?

@Guy Lavoie is correct. If it's a bathroom exhaust fan, it's an inductive load which can damage the switch, especially when initially starting it, as the inrush current is higher than when in running state. You'll have to look, but I'm fairly certain Insteon docs mention this.

Since this is for the isy994 you'll need to get an Insteon on/off... the i3 paddle that can do both dimmer and on/off jobs isn't fully compatible with 994.

Even when a 2477D is set to 100%. There is a short time near zero crossing. There is a time before it conducts. If the fan is inductive. That short no conduction can also lead to issues. Can't say about a I3 paddle. 2477S is also an on-off style.

Thanks guys, always a goldmine of information here. Ordered the on/off version yesterday.

Just for future info:

bathroom fans are cheap-a** shaded-pole motors. They respond very well to dimmers - in fact, this is a common method of varying speed.

That said - I agree an ON / OFF switch is a solid solution, and would also be my choice.

I had my bathroom remodeled a year ago. The electrician subcontractor removed a ceiling light fixture (that I had on a 2477D dimmer) and replaced it with a basic LED fan/light combo from Lowes. Within a week the fan motor failed (made a humming noise but wouldn't turn on). By the time the sparky came back to replace the fan, I had switched the 2477D for a 2477S switch. New fan has been working fine since. I would not recommend using a dimmer with one of these fans.

EDIT: The 2477D was fine. I'm using it on another LED light fixture in the same bathroom.

Edited 20 hours ago20 hr by IndyUDIuser