Model MBGR24H-58 Ice forming on the door light switch

[Tito]

Is that switch located inside the cabinet next to the fan?

[fixbear]

Door not fully closed or door gasket.

[constable]

Hi ,

in regards to my MBGR24H-58 yes it does have the light switch mounted near the fan it’s mounted near the left front corner if your facing the cooler looking through the door. I took the metal cover off the back of the cooler that covers the drain hose and it seems clear . What do you think could be causing ice to form on electrical connections of that switch. Also I do not believe the door gasket is bad because I do not see any condensation around the outside of the door or gasket also this cooler has no problem gettng down to 22 degrees

[fixbear]

There has to be a migration of moist outside air into the cabinet going through the switch. Check that the cabinet vents are clear so there is no negative pressure. Normally the switches are in the Munion close to the heaters.

[constable]

Thanks Fixbear for the quick reply , but

I couldn’t find any vents to see if they could be blocked or not. Where are they usually located on that model ? Also could the metal plate the switch is mounted to cause a leak? Because it dosen’t have any type of gasket on it

[fixbear]

Freezer case vents are normally in the back top of the case near a corner.

How close is the switch to the munnion heater for the door gasket? Is there ice anywhere else?

Masterbilt provides very limited support. The cases I’ve worked on have been under designed and difficult to get parts and information from them. Especially the Danfoss SC12 compressor and start system they use. Low temp cases are a different animal from coolers. Yet they look so alike on the outside.

[constable]

Fixbear Are the Freezer case vents inside the back of the case or the Outside ?

I’m not sure how close the switch is to the munnion heater I’d have to take that top panel down where the fan is to see

There is no ice forminging anywhere else on the unit .

Fixbear could the heater not be getting warm enough to keep ice from forming on the switch ?

[fixbear]

You should be able to just touch the Munion where the door gasket is and feel heat. How close is the switch to the munnion. Obviously with the symptoms you have related to the switch is cold. but is it supposed to be?

Is it supposed to be sealed? I don’t know without seeing it.

What appears to be happening is when the box goes into defrost the coil heater is getting hot enough to make steam. (They always make vapor) It then condenses in the highest and coldest part of the case. The light switch!. The freezer then comes out of defrost and the coil gets into the teens or 20’s before the fans start. This cold blast sets any condensed moisture where it is. Now there are no air currents inside a switch for it to re-evaporate. So either the manufacturer has to heat the switch or use a sealed switch. Most are placed outside the gasket for this reason. Or they use a reed switch and magnet. I don’t believe they would use a silicone booted sealed switch due to the rubbing motion of the door. But I could be wrong. It is something that easily gets torn off if it had one. BTW, freezer case products never get warm during the defrost unless something is wrong. However, the top of case may get above freezing as heat rises. But there is never any fan to circulate till the coil is freezing again.

All products going into a freezer have to be closed and sealed. Repeat, ALL! If not the moisture will be excessive on the evaporator coil. So make sure it is not being used as a quick product chiller without coverings.