Most times I have seen either a bad switch or broken vacum lines. you might want to make sure that none of the line got mixed up if they were removed at some time.
Where is heater control switch
If you are talking about a wall switch for the heater, check to see if the heater has its own internal thermostat or switch as this might be in the off position and not allow the heater to turn on. If you are talking about a switch on the heater itself, then yes in all probability the switch is not working.
First check your fuses. Next check your fan to see if it is working and if the wires are hooked up. The fan is located in the engine compartment on the passenger side. If the fan tests good it is your heater relay located on the heater core cover or the fan switch on the heater control. The heater control is in the passenger compartment. The fan switch will usually work on at least one setting.
Remove the heater control switch decorative cover. Remove the retaining screws. Remove the wiring harness. Reverse the process to install the new switch.
The 1992 Acura heater control relay switch can be found beneath the passenger side dashboard. The heater control relay switch will be a few inches above the kick plate.
Check the fuse
It could be the high speed heater motor relay is stuck on or the switch itself is broken.
It is either the fuse or relay. also check the heater/ ac control switch.
It adjusts the heat in the car so you can control your AC and heat to the temperature you like.
Check for bad relay. Comtacts in relay not opening......Kem H.
Check coolant level Test and/or replace thermostat Make sure heater core is not plugged restricted, or air bound Make sure coolant is being circulated by water pump Check heater control switch and /or cable
To turn on a Rheem water heater, locate the gas control valve or the power switch on the unit. For a gas water heater, turn the gas control valve to the "on" position. For an electric water heater, flip the power switch to the "on" position. Wait for the water heater to heat up before using hot water.