I have a carier weathermaker furnace that shuts off before reaching temp. any idea what could be the problem.

Will it come back on if you immediately turn the thermostat up? If so, it could be a poorly calibrated thermostat. You may need to set it on 80 or something to hold the typical 72.

Otherwise it could be a bad limit switch or relay. If you need help with them, post back giving more details of the furnace. I need more to go on than a Carrier Weather Maker.

The furnace is a58sxc080-gg high ef. Carrier weathermaker furnace. It seems to cycle on and off a lot before reaching thermostat temp. We had a flood a while back so I had to replace motherboard and blower motor. The water came up as high as the vent motor but it still works. I have a new thermostat on now and have same problem.
Thanks