What were they doing?

I was seeing the TV the other evening and I saw a commercial for some heating and air conditioner contractor advertising their heat and cooling system loft services. They were showing everything that the heating and air conditioner specialist does. One thing I did not recognize what they were doing was at one point in this commercial they were truly washing the central heating and air conditioner plan component with a water hose! I have never seen that done before. I wonder what that was for? I recognize hosing down your central heating and air conditioner plan component after a messy storm may be a superb plan just so it isn’t entirely dirty, however why would a heating and air conditioner specialist be doing this? I almost wanted to call the heating and air conditioner contractor that was on the commercial and ask them! It entirely interested me. Was it just for show to look cool or was this something that has to do with heating and air conditioner repair that I do not recognize about? I entirely would appreciate to find this out. Maybe I will just ask my own heating and air conditioner specialist about it the next time they come to do some labor on my own central heating and air conditioner plan unit. I do not know. But I entirely wanna recognize what was going on! Heating and cooling systems are a mystery to me, I only recognize how to turn them off, turn them on and follow up with all the heating and air conditioner repair that needs to be done on the heating and cooling units.

hydronic heater