This is new Thermostat.
This winter I installed honeywell rth230b.
Heater works great, but I have no a/c.
My electrician says that the Thermostat is defective. I do not believe this.
The thermostat kicks in but the A/C does not come up.
Any help will be appreciated.
Thanks.

When you did the install did you jumper between the two R terminals? That's needed if you are running both AC and heat from one 24 v. transformer.