Bathroom ceiling fan has stopped working

Possible wired neg to pos and pos to negative.

check the circut breakers too.

you take the bad light bulbs up . then buy the same model lights .install them on the switch.
ceiling light

here is a link to the part you want and lowes sells this also

http://www.truevalue.com/product/Kitchen-Bath/Bath-Fans/Bathroom-Fans/Bathroom-Fan-Motor-Blower-Wheel/pc/9/c/125/sc/1269/23309.uts?refineByCategoryId=1269

Right now a single switch turns on both light and fan.
You want to put in a double switch to control light and fan separately.

But the problem is there is not a separate wire to each the light and fan.
You need a separate wire to each, but the circuit wasn't wired that way.
Usually when the circuit is wired for separate control, there is a red wire that also goes to ceiling box.

Unless you run another wire to the ceiling box, it won't be possible to control light and fan separately.

Electrician can do this pretty easily if there is attic space above bathroom.

You will have to paint over your new paint with a primer called BIN which will dry in about an hour. Then you can put your color coat on that. Problem solved.

fan blades touching sides of housing,also runs caused by back draught

Yes, very possible!. The bathroom fan is connected together, and the upstairs one is down-drafting to you. Have the exhaust checked for blockage, or buy a fan that has a built-in damper that closes the exit when not in use.

Amazon.com: bathroom ceiling heater Broan Product Detail

If you have the old Thermador ceiling type of heater that must be mounted on the ceiling surface there aren't many choices. Only the Broan-Nutone 154 & 157 models. The 154 @ $37 didn't seem to last too long but it's 1/3 the price of the radiant 157 model at about $100+ dollars. The radiant model may last longer

You'll be able to access the motor to service it and the wiring junction box from inside the bathroom. Please rate this answer if it was at all helpful.

thermostat on the fixture is busted