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Replacing a bathroom fan switch

26K views 4 replies 4 participants last post by  cmacjr22 
#1 ·
Yesterday after taking a shower I attempted to turn on my bathroom exhaust fan. It did not come on immediately and after jiggling the switch, I got it to come on. This told me the switch was bad. I want to first explain the configuration of the switch box. There are two switches, one controls a 3 light bar over the sink. It is a single pole switch. The other controls the fan with no light, just a fan. That switch is what I thought was a 3 way switch. It is an old Pass & Seymour switch that only has push terminals on the back, no screws and there are 3 terminals, one on the upper right and two on the left. These have an arrow to each terminal marked as "common feed thru". Is this in fact a 3 way switch? I thought those were only for operating a fixture from 2 different switches. The circuit that these switches are on is a 15 amp and also on this circuit is my hallway light, the outlets in the bedroom directly across the hall and the outlet for my audio/video equipment in the living room which is on the same wall as the bedroom. There are 4 sets of 14/2 wire coming in to the switch box in the bathroom. All of the white neutrals and grounds are connected inside the box, I didn't mess with that, It should have been a simple switch replacement. I have identified and marked the four black wires coming in to the box as 1) the lead to the fan, 2) the lead to the light, 3) the lead to the other outlets in the circuit which have to hot all the time, and 4) the power supply from the main panel. There is a fifth short piece of wire which is a "jumper wire" from one switch to the other. I have connected the hot supply from the panel to the common on my new 3 way switch, the jumper wire then takes power to the other switch which should feed constant power to the rest of the outlets in the circuit. Everything works fine the bathroom light and the hall light and all the other outlets, until I turn on the bathroom fan. Then all the outlets and hall light go out. I am terribly baffled by this and I keep going back to this switch that I'm replacing. As I understand a 3 way switch does not say on/off on them but the one I removed has 3 terminals on the back. Is this a different kind of switch that I need or what could be the problem? I appreciate any responses and apologize for being so long winded.
 
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#2 ·
No one is going to read that long post. Please condense it and ask the questions.
I am going to answer your question by the thread title.

1) remove switch from box.
2) mark the wires that go to the switch. Any wires that must come apart must be marked so you can put them back like they were.
3) Install new switch and connect using the marking system described above.
 
#3 ·
Yesterday after taking a shower I attempted to turn on my bathroom exhaust fan. It did not come on immediately and after jiggling the switch, I got it to come on. This told me the switch was bad. I want to first explain the configuration of the switch box. There are two switches, one controls a 3 light bar over the sink. It is a single pole switch. The other controls the fan with no light, just a fan. That switch is what I thought was a 3 way switch. It is an old Pass & Seymour switch that only has push terminals on the back, no screws and there are 3 terminals, one on the upper right and two on the left. These have an arrow to each terminal marked as "common feed thru". Is this in fact a 3 way switch? I thought those were only for operating a fixture from 2 different switches. The circuit that these switches are on is a 15 amp and also on this circuit is my hallway light, the outlets in the bedroom directly across the hall and the outlet for my audio/video equipment in the living room which is on the same wall as the bedroom. There are 4 sets of 14/2 wire coming in to the switch box in the bathroom. All of the white neutrals and grounds are connected inside the box, I didn't mess with that, It should have been a simple switch replacement. I have identified and marked the four black wires coming in to the box as 1) the lead to the fan, 2) the lead to the light, 3) the lead to the other outlets in the circuit which have to hot all the time, and 4) the power supply from the main panel. There is a fifth short piece of wire which is a "jumper wire" from one switch to the other. I have connected the hot supply from the panel to the common on my new 3 way switch, the jumper wire then takes power to the other switch which should feed constant power to the rest of the outlets in the circuit. Everything works fine the bathroom light and the hall light and all the other outlets, until I turn on the bathroom fan. Then all the outlets and hall light go out. I am terribly baffled by this and I keep going back to this switch that I'm replacing. As I understand a 3 way switch does not say on/off on them but the one I removed has 3 terminals on the back. Is this a different kind of switch that I need or what could be the problem? I appreciate any responses and apologize for being so long winded.
One of the screws may be for a ground wire, it is normally a green screw. Regular switches have 2 screws on one side, and you switch the hot. The neutral is never connected to a switch.

If you only have one switch for the lights / fan - if it if only switched from one location, then you need a regular 2 way switch, a .39 cent one from walmart will work. (likely way it is setup - but it is possiable power comes into the fan box directly) You should have 2 hots - one that comes into the box, and then one hot that goes up to the fan. Make sure you are only switching the hot(black) that goes up to the fan. DO not switch the neutral or connect it to the switch in any way. Make sure all of the power is off, you may have multiple circiuts running though a box.

Jamie
 
#4 ·
Ok, the way I understand it is you have a rare and "special" switch. It has a common wire in, a pass through, and a switch power out. You do not have a 3-way switch. What you need is a standard single pole switch to replace the existing switch, and to connect another short pigtail to the new switch. The two pigtails off the switches will tie in with the power in and power out wires in the box, and the fan and light wires will connect directly to their respective switches.

I have identified and marked the four black wires coming in to the box as 1) the lead to the fan, 2) the lead to the light, 3) the lead to the other outlets in the circuit which have to hot all the time, and 4) the power supply from the main panel. There is a fifth short piece of wire which is a "jumper wire" from one switch to the other.
Wire 1 should go to your new and second switch, wire 2 should go to the first switch for your lights (leave connected), wire 3 should tie in with wire 4 and 5 and a new pigtail to the second (new) switch.

Post back with the results.
 
#5 ·
Problem is solved. I was thrown off by the old fan switch, it appeared to be a 3 way when in fact it was a single pole with 3 terminals. 2 of them were marked as "common feed thru" which enabled power to be sent to the fan, light and rest of the outlets on the circuit with only one pigtail. My house is forty years old and the switch appears to be as old and they aren't made that way anymore. I was trying to duplicate what was already existing by use of the 3 way switch. All I had to do was create a second pigtail off the main power supply wire and splice 4 wires; main power, the lead to rest of outlets on the circuit and 2 pigtails. I then ran the fan lead to 1 single pole switch and light lead to another and a pigtail to each. That made my light and fan switched and the rest of the circuit hot all the time.

Thanks to all who tried to help.

P.S. To J.V. I've seen many posts on here that are as long or longer. You have to give complete info if you want a good answer.
 
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