electric baseboard heat
I have 7 different size separate electric baseboard heaters in my basement. There is one thermostat. Only 3 of the heaters get hot when you raise the heat. All the breakers are on. They look like they are the original heaters. The house was built in 1972. Any ideas as to why the other 4 are not getting hot? Thanks
They could be burned out or disconnected. Or never connected. Or on a different thermostat at one time, then that thermostat removed and disconnected. Or wired wrong.
No telling what someone may have done in the past!
Is the room warm enough with just those 3?
If you are going to try to get the others working, you would be best to double check the wattage and voltage of each (label on heater). Then check the wire size, breaker, etc. to be sure everything is as it should be to handle the load.
Also check the wattage of the thermostat. It is possible that someone kept installing an undersized thermostat and it kept burning out, so their solution to the problem was to disconnect several of the heaters.
In that case, before reconnecting the other heaters, you would need to get the correct wattage thermostat. Again people don't wire or fix things like they should sometimes.
Here you can use a calculator to determine amperage based on total wattage...
(Use single phase and 120 volts or 240 volts as appropriate.)
They are either NOT getting power, or they are getting it but are not USING it. The two problems are different, and either one could have many different causes. The only way to tell is to be there and test the circuits and the units.
Seven heaters, unless they are all only 2' long, would never be on just one circuit.
If there is only one t-stat than it is most likely that this is a relay system with a low-voltage t-stat.
I suspect a bad relay.
Do you have some silver boxes near your electrical panel with the name Allen-Bradley on them?
Is the t-stat a simple round easy to turn piece?
There are 2 30 amp breakers for 2 8' long heaters and 2 20 amp breakers for the other 5 heaters (4- 2' long 1- 8' long). The 2 30 amp breakers are off but when I put them on I still don't get any heat out of those 2 heaters. I get heat off of 3 out of the 5 heaters on the 20 amp breakers. 1 8' and 2 2' are working. It's a round t-stat with 3 wires but only 2 are connected, the red and blue. The green is not being used. There's a small silver box with white - rodgers on it near the panel. Thanks
The box likely contains relay(s) and maybe the low-voltage transformer needed by the thermostat. Pop the cover off and take a look. Sounds like a relay is bad, or, as mentioned, they were not all hooked up.
It would be unusual for one thermostat and relay, to control circuits from two different circuit breakers. It would take a 4 pole breaker and that is usually too sophisticated for the average installation.