HVAC Heat Shortcycling

Get a real technician. The one you have has no clue. Any GOOD technician can find the problem. It's easy for him to say replace the furnace because he doesn't have a clue what is wrong.

My HVAC came he checked few things here and there and suggest to replace the heater 

Another Salesman!

Find a different service provider.

Where are you located?

Thats a problem between you and the contractor. I would put it on a CC then dispute the charge!

Call and complain.

Sounds like one of the low special contractors that just want to get a foot in the door to sell.

Have you changed your air filter and ensure that all supply registers and dampers are open . Had the same thing happen to a friend recently another company suggested to replace the furnace because it was old 11years old installed by them . Ended up his filter which they said was clean was packed replaced it and all was good higher end aprilaire electronic air cleaner of course w the wires broken and filter packed again installed and serviced by them for 10 years never changed filter never clean condenser service agreement lol . They also stated that the unit must be leaking because of water marks near the burner it was really the fact they never insulated the suction line which for 10 years of them servicing every service guy was to lazy to put a piece of insulation on the suction line total hacks ,They have been suggesting replacement when the unit hit 11 years old gotta keep the revenue coming in i guess also when they installed they never did a chimney liner i had alert my friend of it and he blew it off for a few years until his chimney was falling apart and i reminded him and he had it lined .They where so good and trained as they state in every ad they run w nate trained employees (lol money grab bs er) that they wired the eac straight up powered all the time after it was first put in i walked in the door and could smell the ozone it produces alert him of the issue being his wife and daughter have respiratory issues . I took a closer look and saw that it was wired directly not to the provided eac terminals on the furnace. The bonus was that being it was total there mistake they wiped out a few grand that he owned them being they realized they where in a legal pickle for the neglect especially since the eac had a huge orange label on it stating that it produced ozone and should only be powered when the blower is operating , This was and is a large franchise company advertising everywhere pretty much in a lot of states and all i could say was yeah i work for myself instead of working for money hungry idiots . And another note there prices for a cold call service call are way to cheap for a real service men but it's about right for a salemens, also they always offer service maintenance contracts most are all bull and most of the time they do absolutely zip. I surely know your noy getting me out bed for 79 to 119 bucks all you would hear is a ring tone my time is worth more then that . You most likely would be in the same boat w public utilities worry free what me worry quote alfred e newman

peace and good luck clammy

Replace the board. it controls all functions of the systems and if it goes haywire like its doing its most likely bad.