Water heater switch

[Hamnet]

I just changed out my interior water heater paddle switch. I swear I did just like the old one. I was running a small fan from the kitchen gfi plug, when I switched the water heater on the fan speed slowed, turned it off and went back to normal speed. I used one of the household tester and the lights on the tester said "hot & nuetral switched". The switch tells what side black and white wires go on. I am connected to power supply. Need help. Thanks

[Old-Biscuit]

If the switch is a 120V AC switch you did get another 120V AC switch and not a 12V DC switch?

[enblethen]

Make and model of water heater?
Is there an exterior maintenance switch?
I am guessing you may have an element going to ground.
What type of shore power? 30/50? What type of receptacle are you plugged into?

[wa8yxm]

Two switches that LOOK alike, might not be.. Do you have the switch specifications handy where you can post them.

Or failing that a photo of the REAR of the switch.

[Hamnet]

I am connected to power from my house which I always do when parked at my house. I have a seperate outlet for the RV. I am baffled, never had an issue until I changed out the switch. I must admit we haven't used the switch for a couple years because it didn't work. The water works fine when using propane.

[newman_fulltime]

Maybe it has a better connection and now pulling more amps than it use to so you are seeing the diff.
Or if it is a suburban hwh the wires are loose in the box and are arcing some it does happen

[1492]

Moved from Forum Technical Support

[enblethen]

Black and white wires? Is this the switch for a 120 volt element in your water heater?
Could be loose connection in the system.
What type of shore power?
You may have extremely low voltage where you are connected to shore power.

[Mandalay_Parr]

If there are only two wires to the switch, you can't do it wrong.

Suspect poor electrical connection somewhere else.