I need more info, the only way your heater could freeze up is if the outdoor unit was running when it isn't supposed to be. Go outside and look, if the unit is running turn the breaker at the unit off or the breaker in the house. Let me know if this is the case, also tell me more about the system, is it a heat pump or a gas system?
Its not a gas outside unit
Ok so while it is running I need to turn off breaker?
Now my heater is shut off
And I turned it back on.
Thanks for the answers, but I'm still hoping for more ideas.
Charity, perhaps if you post some pictures (or video) of where the unit is freezing up. Perhaps someone can spot the problem.
Ok ill try. Its ice around the bottom of unit.
It sounds as though you have a heat pump system and its icing up and not going into the defrost mode.
You can use your emergency heat switch by turning it on. This will turn off the outdoor system and work only as electrical resistance heat until it defrosts. The thermostat will work as normal, just the outside system will not run. I would leave it in emergency heat mode until you can get a service person there to fix the issue. It can be a bad timer, switch,, or reversing valve. By keeping the system off will allow the outdoor unit to defrost, may take several hours, but the most important thing it will prevent the compressor from failing.
It does go into defrost
If it does go into the defrost mode and its still frozen then the timer is at fault or you may be low on refrigerant. As it begins to leak out the temps get colder before they warm up. in any case if its not defrosting completely use the emergency heat and call a HVAC contractor for service so you do not burn out the compressor.