My BM23 turns on when I turn the thermostat up but the evap fan does not turn on. Should the evap fan run all the time or only when the thermostat turns the compressor on?

first are the evap coils one big ice block? if so melt the ice and look for a air gap in the door gasket. the comp. turns on so the thermostat is sending the signal to turn on. on these the drain from the evap (cold part/ top) could be blocked. blocked drain, water sits, then freezes and blocks air flow

you should hear a click when going to the off position and another click when turning on or take it out and measure resistance on both position with a multi volt meter with beeping sound.

yes sounds like a bad defrost terminator or timer?
not allowing it to go into defrost so compressor runs all the time and it frreezes up

Hello,
I am not sure if their a schematic online for that brand but the circuit is going to be like this

120 volts at plug
neutral side of fan wired directly at all times
Hot side from plug into thermostat
out of thermostat into defrost timer
out of timer to evap fan motor
hot from,plug to t-stat to defrost timer finally to evap. fan plus neutral side at evep motor makes it run

Hi,
It could be either....
It is best to check and see if you are getting power to the fan...power to fan, the fan is bad...no power the board is bad...

heatman101

Not familiar with this thermostat but you can figure it out if you know how to use a meter. Sounds like they want you to run both power and neutral threw the thermostat OR it is one that either opens on temp rise or closes on temp rise. Also, the wire tapped into the black one for the fan is probably to energize the fan 24/7 as the original may have been damaged.

I would definately start there. That is what contols the cycling of the compressor.

if the evap fan is not turning try to turn it by hand a few times then start you freezer if it does not turn it needs to be replaced.make sure there is no ice build up on the evap coils.alos check the continuity of the defrost heater below the evap coils.once you het teh fan replace your unit should cool down to the proper temps.

If this is a Bev-Air, don't think the door switch will control the fan. At the evap, there is a temp sensor called a fan delay. When unit goes into defrost mode, this warms up. Some also serve a dual purpose. It will terminate the defrost cycle at a certain temp., say 51 degrees or so, at the evap. Anyway, when unit comes out of defrost, it keeps the fan off so it allows the evap to cool quicker and to prevent circulating warm air. This could be your problem. Not a hard fix but they can be a pain sometimes. Outside chance that the unit is low on refrigerant (freon). This will not let the evap get cold enough to trip the sensor back into position to turn the fan on. Good Luck. Restaurant Parts and More carry alot of Bev-Air stuff. 1-888-814-1110. Ask for Rick

Its normal