Bathroom fan switch amperage

[pete6032]

I am going to install an exhaust fan timer switch in my bathroom. I see they come in 15 or 20 amp variety. What is recommended? Is it OK to get a 20 amp switch and use it on 15 amp wiring?

 

[Greenman]

15 or 20 amp switch is fine, unless the fan is also a heater, then it should be a 20 amp.

 

[pete6032]

15 or 20 amp switch is fine, unless the fan is also a heater, then it should be a 20 amp.

It's not, just a standard exhaust fan with 100w bulb. I will have to take the old switch off to see what type of wiring is behind there. Sounds like each type of timer switch needs differing wiring types. My home was last wired in early 2000s so hopefully the wires I need will be there.

 

[Greenman]

It's not, just a standard exhaust fan with 100w bulb. I will have to take the old switch off to see what type of wiring is behind there. Sounds like each type of timer switch needs differing wiring types. My home was last wired in early 2000s so hopefully the wires I need will be there.

The only thing that could nix it is if there isn't neutral in the switch box.

 

[sdifox]

I am going to install an exhaust fan timer switch in my bathroom. I see they come in 15 or 20 amp variety. What is recommended? Is it OK to get a 20 amp switch and use it on 15 amp wiring?

Why would you need a 20A switch for a bathroom fan? You do want a GFCI socket in the bathroom though. Replace the bulb with a LED one.

 

[PowerEngineer]

Why would you need a 20A switch for a bathroom fan? You do want a GFCI socket in the bathroom though. Replace the bulb with a LED one.

"Need" really isn't the right question. It should be "will it work". While a timer switch with a lower rating (down to the actual draw of the fan motor and light) would still be fine, there is certainly no harm in opting for one that is built to handle much higher loads like the 15A and 20A ones that OP has found. FWIW, the engineer in me always wants to go with equipment that is rated for much more than what I expect it to see.

 

[deadlyapp]

"Need" really isn't the right question. It should be "will it work". While a timer switch with a lower rating (down to the actual draw of the fan motor and light) would still be fine, there is certainly no harm in opting for one that is built to handle much higher loads like the 15A and 20A ones that OP has found. FWIW, the engineer in me always wants to go with equipment that is rated for much more than what I expect it to see.

I certainly would always install a 20amp switch or outlet even if wiring and breaker is only good for 15amp. The cost difference is so minimal it makes no sense to do it otherwise and I never have to worry about mismatching lower to higher.

A 20 amp switch will work with 15amp wiring without any issue - generally the only difference is going to be 12 or 14 gauge and the switch can take either (either push through or terminal). You can't get push through terminals on a 20a switch (AFAIK)

 

[Aikouka]

I certainly would always install a 20amp switch or outlet even if wiring and breaker is only good for 15amp. The cost difference is so minimal it makes no sense to do it otherwise and I never have to worry about mismatching lower to higher.

A 20 amp switch will work with 15amp wiring without any issue - generally the only difference is going to be 12 or 14 gauge and the switch can take either (either push through or terminal). You can't get push through terminals on a 20a switch (AFAIK)

Most people don't install 20A outlets because just about no common/standard home devices actually use them. You usually find them on some high-draw power tools such as welders, which some people around here may have in their garage/workshop. You usually run 20A circuits to 15A outlets because you usually wire more than one outlet on a circuit, and it means all outlets together can draw up to 16A.

It's really the same with a switch. They're quite rare due to few devices actually needing that much. The only time I've ever seen one was with my pool pump when it was wired on 110V (15A @ 110V or 7.5A @ 220V). Although, I tend to use digital timers these days with fans (you should keep a bathroom fan running after you're done to help pull out any remaining moisture), and most good bathroom fans pull so little amperage. I put in a Panasonic WhisperFit a few months ago, and I think it's rated for something like 0.2A @ 110V at the highest setting?

 

[Micrornd]

This is what we use in our bathrooms. It turns on and off by humidity and also works as manual on-timed off switch.
It is designed for light and fan or fan only and requires a neutral connection.
https://www.leviton.com/en/products...ensor-fan-control/humidity-sensor-fan-control

 

[Greenman]

Humidity sensor is required here in CA. Also have to have the light on an occupancy sensor.

 

[deadlyapp]

Most people don't install 20A outlets because just about no common/standard home devices actually use them. You usually find them on some high-draw power tools such as welders, which some people around here may have in their garage/workshop. You usually run 20A circuits to 15A outlets because you usually wire more than one outlet on a circuit, and it means all outlets together can draw up to 16A.

It's really the same with a switch. They're quite rare due to few devices actually needing that much. The only time I've ever seen one was with my pool pump when it was wired on 110V (15A @ 110V or 7.5A @ 220V). Although, I tend to use digital timers these days with fans (you should keep a bathroom fan running after you're done to help pull out any remaining moisture), and most good bathroom fans pull so little amperage. I put in a Panasonic WhisperFit a few months ago, and I think it's rated for something like 0.2A @ 110V at the highest setting?

There's no physical difference between a 20A and 15A outlet or switch though if it's a normal outlet. Which is why I can't see why I would use less if I was installing a new outlet. Yes I agree with you that there are very few times where I'd actually use more than 15A other than in the garage but I don't want the construction of my outlet to limit it - I want the wiring and breaker to limit it.