Production beekeeper Michael Palmer in his video about extracting honey at French Hill Apiaries, mentions his hot room, in which he keeps supers at 100F (37C) to facilitate extraction.
Long ago I’d heard about putting a light bulb under honey to warm it up. This spring I devised a simple, low-cost, trouble-free option to a hot room where I can heat a single stack of supers. My costs were under $30.
On my first try, set at 99.9F (37C), this unit brought a stack of 4 medium supers of 46F honey up to 99.9F in about 36 hours. This little heater made it a breeze to uncap and extract. Electricity cost for 7.2 kWh is less than $2. The set up could probably be used to degranulate jars or 5 gal buckets as well.
I purchased a $15 120V digital controller (Amazon) to drive two 100W light bulbs set underneath a stack of honey supers. Whenever the temp is less than 99.9F the lights turn on, and at 99.9F the lights go off.
The supers stack on top of the heater base, and the controller and sensor mount to an insulated cover set over the stack.
In the base, the bulbs screw into porcelain fixtures offset on opposing insides of a cast off medium honey super. They are wired in parallel. Each side of the line from the lights connects to opposing sides of a wall outlet. One side of the outlet feeds directly to the plug. The other side of the outlet line feeds through an on/off switch, before joining the other side of the plug. The plug wire to the wall is a heavy duty stranded extension cord type. The wiring inside the box is Romex cable which can be neatly stapled to the inside of the super.
A couple of thin plywood shields cover the bulbs from dripping honey. I also added a couple of 1x2 stand offs to suspend the base above the ground to aid in upward air circulation. I covered the nails with felt pads (so my wife’s floors remain intact). Whatever hardware I didn’t have hanging about came from Home Depot.
I used a homemade outer cover and lined the honey side with hardboard half-inch foil-faced foam. A small hole is drilled at the center of the cover to provide access for the temp sensor probe, which dangles inside the cover above the honey. The controller is mounted on the top of the outer cover inside a plastic rough-in box to protect it.
The controller terminal strip has four two-wire outputs: 120v out for power; two wire sensor loop; two wire heating loop; and two wire cooling loop (not used).
• 120v power wire – I chopped apart an extension cord leaving the wire (to controller) and plug (to the wall)
• Sensor loop – comes pre-wired with sensor
• Heating loop - I chopped a second extension cord as above and wired it into this loop. Leave wire long enough to reach down the super stack to the heating base. It plugs in there. DO NOT PLUG INTO WALL it will fry the controller. As this line carries the heating loop power, I chose a larger gage extension cord to handle the load.
• Cooling loop - not used
Two things plug into the wall or power strip: the controller power, and the light base.
(The controller may optionally be wired to provide power to the output, but because of the 200W load I chose to independently power the lightbulbs.)
When the sensor calls for heat, it activates the controller’s heating relay which connects via plug to the outlet/receptacle on the base where the heater lamps are located. If the base is plugged in and switched on, the circuit is complete and the lights go on.
The lights are wired separately from the controller. The light circuit is interrupted by a switched outlet. The switch is a redundant on/off for the lights. The lights will not go on unless the controller circuit is activated and the switch is in the ON position. The sensor triggers the on/off or heat/no heat relay in the controller which completes the circuit to energize the lights.
The controller power is separate from the lighting circuit. The controller plugs independently in a 120v outlet.
Bill of Material:
1 Scrap 6 5/8 deep medium super or full deep
1 Scrap outer cover or make one
1 Insulating foil faced foam to fit inside outer cover
2 Scrap 1x2 pcs 15” long for base standoffs
3 extension cords 6 ft (2 that are heavier duty)
2 porcelain unswitched bulb holders
2 round rough in boxes (if you don’t want to mount the porcelain directly to the super)
2 100W light bulbs
1 2-gang outlet
1 single throw switch
1 double size old work rough box
1 cover plate
a/r Romex or wire for inside the super
a/r Wire staples
a/r Wood/dry wall screws to mount the porcelain and controller
1 digital controller (amazon)
1 Appropriate housing for mounting and protecting controller
(I used a blue plastic new construction rough-in box with securing clamps)
Hope this helps someone!
Long ago I’d heard about putting a light bulb under honey to warm it up. This spring I devised a simple, low-cost, trouble-free option to a hot room where I can heat a single stack of supers. My costs were under $30.
On my first try, set at 99.9F (37C), this unit brought a stack of 4 medium supers of 46F honey up to 99.9F in about 36 hours. This little heater made it a breeze to uncap and extract. Electricity cost for 7.2 kWh is less than $2. The set up could probably be used to degranulate jars or 5 gal buckets as well.

I purchased a $15 120V digital controller (Amazon) to drive two 100W light bulbs set underneath a stack of honey supers. Whenever the temp is less than 99.9F the lights turn on, and at 99.9F the lights go off.
The supers stack on top of the heater base, and the controller and sensor mount to an insulated cover set over the stack.
In the base, the bulbs screw into porcelain fixtures offset on opposing insides of a cast off medium honey super. They are wired in parallel. Each side of the line from the lights connects to opposing sides of a wall outlet. One side of the outlet feeds directly to the plug. The other side of the outlet line feeds through an on/off switch, before joining the other side of the plug. The plug wire to the wall is a heavy duty stranded extension cord type. The wiring inside the box is Romex cable which can be neatly stapled to the inside of the super.
A couple of thin plywood shields cover the bulbs from dripping honey. I also added a couple of 1x2 stand offs to suspend the base above the ground to aid in upward air circulation. I covered the nails with felt pads (so my wife’s floors remain intact). Whatever hardware I didn’t have hanging about came from Home Depot.
I used a homemade outer cover and lined the honey side with hardboard half-inch foil-faced foam. A small hole is drilled at the center of the cover to provide access for the temp sensor probe, which dangles inside the cover above the honey. The controller is mounted on the top of the outer cover inside a plastic rough-in box to protect it.
The controller terminal strip has four two-wire outputs: 120v out for power; two wire sensor loop; two wire heating loop; and two wire cooling loop (not used).
• 120v power wire – I chopped apart an extension cord leaving the wire (to controller) and plug (to the wall)
• Sensor loop – comes pre-wired with sensor
• Heating loop - I chopped a second extension cord as above and wired it into this loop. Leave wire long enough to reach down the super stack to the heating base. It plugs in there. DO NOT PLUG INTO WALL it will fry the controller. As this line carries the heating loop power, I chose a larger gage extension cord to handle the load.
• Cooling loop - not used
Two things plug into the wall or power strip: the controller power, and the light base.
(The controller may optionally be wired to provide power to the output, but because of the 200W load I chose to independently power the lightbulbs.)
When the sensor calls for heat, it activates the controller’s heating relay which connects via plug to the outlet/receptacle on the base where the heater lamps are located. If the base is plugged in and switched on, the circuit is complete and the lights go on.
The lights are wired separately from the controller. The light circuit is interrupted by a switched outlet. The switch is a redundant on/off for the lights. The lights will not go on unless the controller circuit is activated and the switch is in the ON position. The sensor triggers the on/off or heat/no heat relay in the controller which completes the circuit to energize the lights.
The controller power is separate from the lighting circuit. The controller plugs independently in a 120v outlet.




Bill of Material:
1 Scrap 6 5/8 deep medium super or full deep
1 Scrap outer cover or make one
1 Insulating foil faced foam to fit inside outer cover
2 Scrap 1x2 pcs 15” long for base standoffs
3 extension cords 6 ft (2 that are heavier duty)
2 porcelain unswitched bulb holders
2 round rough in boxes (if you don’t want to mount the porcelain directly to the super)
2 100W light bulbs
1 2-gang outlet
1 single throw switch
1 double size old work rough box
1 cover plate
a/r Romex or wire for inside the super
a/r Wire staples
a/r Wood/dry wall screws to mount the porcelain and controller
1 digital controller (amazon)
1 Appropriate housing for mounting and protecting controller
(I used a blue plastic new construction rough-in box with securing clamps)
Hope this helps someone!