I used two bottles; after the first one initially unclogged the radiator, the blockage moved further along. I kept the liquid inside for a week. Now the radiator provides heat when the car is moving but very little at idle.

I tried it on two cars with a pump in the internal circuit of the heater without passing through the main radiator circuit. On a Suzuki Jimny, after a while of sending the fluid along with hot water, there was a pop and the flow started to become normal. That is, the water that the pump sent came out with the same pressure from the outlet, whereas at first it seemed clogged. Now the heater really heats. On a Corolla Verso, it didn't work even though it cleaned it, probably because the problem is a blocked valve or flap. Rinsed at the end with deionized water again with a pump and after the engine runs, topped up with antifreeze

It cleaned the refrigerator which produced quite a bit of dirty water ...there was a cleaning done 2 times with the cleaning liquid and 6 times with just deionized water...after it cleaned the water quite a bit, I added the antifreeze...I think it did a very good job removing pieces of rust and scale residues...

Pay attention to the various additives for the refrigerator, one helps with leaks, the other with not raising the temperature, etc. Over time, they create problems due to chemical reactions between them, the sensor-the thermostat-the expansion tank-the cap, etc. Empty all the existing antifreeze, pour distilled water and this additive, drive the car for about 30 kilometers (also turn on the heater), empty it, put only distilled water, let it idle for a while or take a few rides to warm up and then remove to rinse off any residue. Then antifreeze with distilled water, venting, and finally. I didn't have rust, but after cleaning with this Holts product, the car works better, I have faster heat in the cabin, and the fan doesn't work as often as before, I am very satisfied!

I used 2 packages on a motor that had been inactive for at least 10 years and had a lot of rust. I removed the old water, poured in the descaler along with the cleaner, ran it with gas for about 20 minutes, drained it, and rinsed it with descaler. I did this process twice and it cleaned quite well to a large extent. Of course, at the end I added antifreeze.

Cleaned the car's radiator very well, saw an immediate difference. I took measurements with a digital thermometer before and after, there was a huge difference

The product is EXCELLENT.
I bought it after trying 4 cleaners from liqui moly that DID NOTHING to the cooling system.
I bought it because I had a problem with the car's heater.
It wasn't blowing hot air in the cabin.
(Only when driving, warm air would come out - when stopped, it would blow cold air.)
I used it for two days and on the third day, it started blowing hot air in the cabin.

P.S. The "coolant" needs to be changed to get rid of the dirt (from the radiator cap), and then a good antifreeze should be added.
15/02/2022
I used the cleaner again for the second time and it released a lot of dirt from the cooling system.

The procedure is as follows: With a warm engine, drain the coolant, add the cleaner and plain water, let it run for 20-30 minutes at idle but make sure the fan operates a few times, drain, add only deionized water for 2 days and drain again. [According to other technicians' opinions, for better results, drive a few kilometers but gently without stressing the engine.] Repeat until the water comes out clean and finally fill with an antifreeze mixture. I had overheating problems from an iron pipe that filled the system with rust. With the cleaning, a basin of brown water came out, so it seems it did the job. The metals didn't shine but most of the dirt was removed. I also changed the thermostat and now the engine runs like clockwork without overheating. Never use water without antifreeze, as rust will form in the system.