Even earlier, I bought a heater motor from a gazelle, (it was necessary). I bought hoses, but everything else was found in the garage. Yes, I’ll say right away that tile and gas for heating are necessary. Well, citric acid 3 packs of 20 g. (universal remedy for blockages in the kitchen or in the bathroom, put one bag in the sink and boiling water

In general, the process is simple. We connect everything as in the photo, a bucket of water, and onto the tile, begins to boil, add acid, start the engine, well, we smoke for about 20 minutes. Then we change the water, all the same but without acid and with hot water. If the bucket is very dirty. Repeat with acid and rinse immediately with hot.
It helped me