I have a 2000 Watt 220 convection heater and would like to add another one to the same wire.

Can this be done?
Is it the circuit breaker tripping or melting of the wire that is the danger?
Thanks

A breaker is designed to monitor amperage, and trip if the amp draw exceeds the amp rating of the breaker. This is to protect the wire that is matched to the breaker from overheating due to excessive amp draw.

Before adding more load to any circuit, the wire size and breaker size must be noted, and the total load must be known.

Electric heat is to be considered as continuous load, so the circuit must be derated by 80%, or another way of putting it, increase the size of the branch circuit by 125% of the actual load.

By the way, if your located in USA, standard voltage is 240 volts for residential. So 240 must be used in any calculations.

A 2000 watt load at 240 volts draws 8.34 amps. Min circuit size is 8.34 x 1.25=10.5 amps, so this heater alone will require a min of #14 wire on a 15 amp breaker. A 15 amp breaker and circuit can be loaded to 12 amps.

So, if you have #14 wire, not much more room for more load.

Most electric heat circuits are installed using a min of #12 wire on a 20 amp breaker, and can be loaded to 16 amps. If this is what you have, you can add 8 more amps of load.

If you know the size circuit you have, with this information you can figure this out on your own. If you need more info, get back with your questions.