First of all, hello everyone, let me give direct information about my vehicle and tell its history. My vehicle is Peugeot 1.4 2010 206+ Model LPG Gasoline. Friends, first of all, before my vehicle went to the industrial site, my heater was heating and the temperature was never rising. It was going between 90-100 mph. I never saw any overheating and I didn't see any STOP. I also asked and investigated the temperature to be like this and they said it was normal for these vehicles. I went to the industrial site for a small problem. (Speedometer) was changed. During the process, there was a leak in the radiator. I already knew it so I decided to change it since I was here. A Kale brand radiator was installed and rusty water came out inside. The previous owner had used water so we put water in it. He said to use it like this for 1 week. Everything is ok, they took air etc. I started the vehicle, I went for 5 meters but didn't go, the overheating suddenly increased, it happened for a minute, the STOP warning came on and went off, I stopped immediately. I came back immediately, I went to the shop anyway, it is very close, I went and didn't go in between. Anyway, I took it to the mechanic and he removed it again. He said it wasn't real heat, the upper pipe of the radiator was hot and the lower pipe was cold. He said look, the upper pipe was swollen. He said the thermostat wasn't working, he said it might be defective. When we replaced the radiator, he said there was a problem, it was clogged, so we had to replace the thermostat as well, anyway, it was solved, the upper pipe was hot, the lower pipe was hot, the temperature returned to normal as before, 90 idle in heavy traffic, it rises to the upper line, the fan comes on, drops, etc. On the way home, I decided to turn on the heater. The heater was blowing cold, I realized there was a problem. I called and explained the situation to the mechanic. He said that since we replaced these parts, he started explaining that if there is a problem, it is progressing that way, he said to come back. First, I went to the LPG repairman (a friend of mine), he said the radiator was cold, he removed it, he said the radiator was fine, water came out, put it back in, it warmed up, then the LPG circuit, and that was fixed. I went back to the mechanic, he looked at it again, he said the radiators needed cleaning, maybe that was clogged, I said, I went to the radiator repairman. It continued to blow cold again. My heater which was blowing HOT before is still blowing cold. I had the mechanic clean the radiators again and said the same thing. Oda said let me leave the car for a day and see if we can take it apart and fix it anyway. He said it could be the water pump (under the timing belt) or the 0 thermostat I installed is faulty and if I install it in 0 it can sometimes be like this. He said let's see if that doesn't work and check the pipes. If that doesn't work, Oda said the upper cover can be opened. So as you can see, I experienced these as a result of a radiator replacement. Normally there was no problem in my car, my heater was heating. The temperature was between 90-100, they said it was normal for Peugeot. So I can't get out of this triangle. I went to 4 or 5 mechanics, they all direct them to each other. What should I do, please help me, I am curious about your opinions on this. As a result, the heater in the car is not heating, the pipes going to the heater are cold. I am wondering if there is dirt in those pipes, my problem is just that the pipe needs to be changed etc. I don't know, please help. I am losing money every time I go there, I am out of 6 thousand TL now. May God grant whoever can help me whatever they want. I'm in Kayseri, so anyone who has any recommendations for a mechanic or something can share. I'm worried I'll end up paying 20,000-30,000 lira when I have to replace everything, open the top cover, and replace the gasket. I don't want to go to that mechanic either.