Elelctric radient heating compnents (whatzis?)

Two bedroom, two bath condo with a loft. Electric radiant heating. Built in '82. These are both connected to the radiant heating, pretty sure, but I’m not sure how they work. Do these components look familiar?

How should I report this?
“Second sub-panel, housing components for the electric radiant heating system”?
-box rating
-conductor rating

looks like a low voltage controller that probably has inputs from different sensors or thermostats and when there is a call for heat from a zone or room, the controller closes a contact and 24 v (or some other low voltage from the transformer) is put across the coil of one of the four contactors which closes the line voltage contacts (which are normally open) and energizes the appropriate heater. I’m not sure about that control in the first picture though. In a PLC system most of the field components are inputs or outputs, in this case you (if my guess is correct) have both and it would be called a IO (Input/Output) panel. But in a home I would just refer to it as the ‘heating system control panel’.

An Energy Sentry® Demand Controller…

…makes it possible for you to use the same amount of electricity at a substantially lower cost.
…lowers your electric bills every month of the year.
…has a savings that can be proven every month, unlike other energy cost-reducing products.
…helps electric heated and cooled homes maintain their market value and makes them easier
to sell than homes without demand controllers.
…allows some homes to actually have less expensive total energy costs than a comparable
gas-heated/cooled home, depending on the individual utility rates.


  1. How does it do all that?
  2. What are the settings for on the interface?
  3. Am I correct about the operation of the control panel? ie, low voltage input to control module from zonal sensors, low voltage output from the controller to contactor coils which closes normally closed line voltage contacts to appropriate zone heater.

See http://www.brayden.com/demandcontroller.html and also look at the Residential Products tab as well.

Great information guys, thank you. -Kent


This is a device that operates similar to a commercial energy management system where a company is charged for their peak usage for the entire year based on one time segment recorded. The object is to prevent all the heaters from coming on at one time. It alternates between devices to maintain a maximum draw. The adjustment dial controls the maximum setting. I have no idea why this is in the residential house however. You are correct in assuming this is a low voltage controller operating high-voltage contractors.

"It alternates between devices to maintain a maximum draw"

Wouldn’t this be to maintain mimimum draw or to control maximum draw?

Demand controllers seem like a good idea for homes that use electric radiant heat. Ive never seen one in a home before, but since they appear to lower costs, I’m surprised they aren’t used more often.

Yes, maximum should be minimum. New computer, untrained voice dictation! :slight_smile: