Wondering if anyone can help me please. Can I wire this baseboard (I believe it is 208/240) on 120/240 circuit? I have tried and when I turn the thermostat on it pops the breaker?

Then you wired it wrong.

The term 120/240v is a service rating. You have 120V loads in the house, along with 240V loads (like an A/C, power tool, motors, electric heat, etc), as well as 120/240V loads (like a range or dryer).

With regard to an electric heater, the term 208/240V means it can be wired at either 208V or 240V. At 208V it will simply put out less wattage than at 240V.

Are you related to this post: https://www.askmehelpdesk.com/electrical-lighting/convert-120-208-208-240-a-729832.html
This is not exactly a common question so it's weird to get two in one day.

No, I didn't post that one. Thanks for reply.

I connected one of the black thermostat wires to one of the black heater wires, then remaining black heater wire to the other black thermostat wire. Then I connected a hot supply wire to red thermostat wire and the other hot supply to other red thermostat wire. The breaker pops when I turn the heat up. Any suggestions?
Thanks

Yeah, the two red are one side of the thermostat, the two blacks are the other. So now when you turn up the thermostat it closes red to red and creates a 240V dead short.
Did you see the wiring diagram in the instructions?

Yeah, the two red are one side of the thermostat, the two blacks are the other. So now when you turn up the thermostat it closes red to red and creates a 240V dead short.
Did you see the wiring diagram in the instructions?

No, I do not have the diagram and can't seem to find one online..

http://s3.pexsupply.com/product_files/T498B1553-Submittal%20Sheet.pdf

Scroll down to Fig. 3. In your case both L1 & L2 would be hot.

http://s3.pexsupply.com/product_files/T498B1553-Submittal%20Sheet.pdf

Scroll down to Fig. 3. In your case both L1 & L2 would be hot.

Thanks very much. That works perfectly. I really appreciate it.