Mu car requires DexCool antifreze and my son put in regular antifreeze , now I have no heat

Since I don't know the specifics, or how long ago this was done, I can only speculate. DexCool has had its share of problems, with some people. With good "lab" technique, DexCool is a fine product, in my opinion. It's important to keep the system completely filled (slightly above the "MAX Line" on the reservoir) and not allow air pockets to develop. When I talked to the head of Texaco's DexCool (OAT) development program, approximately 9 years ago in Houston, she said that she recommended draining systems of old, low-silicate antifreeze and flushing the system with distilled water twice before switching to DexCool. This insures there is no compatibility problem with its Organic Acid Technology (OAT). If your son did not do this, it can gel and cause problems. I'm not saying, however, that's what happened in your case. If you didn't keep the system full, free of air, and changed every 3 years, the problem may really have developed before your son even changed the antifreeze.

You should probably drain/flush the system and start over. It's important to only use distilled water or minerals can buildup and block radiators and heater cores. Make sure corrosion or mineral buildup is not the problem with your heater core. A properly maintained radiator and heater core, using DexCool, stays super clean, since there are no borates, phosphates, or silicates. Keep in mind that radiators and heater cores tend to go around 150,000 miles, no matter what you do.

The link below may give you some additional insight:

https://www.askmehelpdesk.com/cars-t...tml#post235973

Hmm, another thought here is why did you need antifreeze added? You could have gotten air trapped in the unit as greasemonkey said. Have the system flushed and try it again.