Questions that you do not ask will come back to haunt you

Today I realised that you should always ask all the stupid questions you can think of when you purchase an aircon. Today I spent half a day figuring out what was that stupid green indicator light that came on suddenly for my indoor unit and how to reset it.

Case in question? My Hitachi System 3 Inverter aircon indoor unit. Below is the image that caused me half a day of trouble.

There was a green indicator light below the grid-light icon. After digging out the manual, I realised that this indicates that my air filter is due to be cleaned. Apparently, Hitachi has added this feature where the indoor unit will remind you to clean the air filter after 100 hours of usage. Okay. Fine. Not a problem. I vacuumed the air filter and fixed it back.

Now the problem came. How do I get rid of the green icon? According to the manual, the green light will disappear if you power off and on the indoor unit. The problem is where is the stupid power switch? After searching high and low, I finally found the main power switch at the aircon ledge. Switching it off will power off the whole aircon system apparently. Fine.

The problem? The green indicator light disappeared after I powered off but it came back on again once the power is on. The manual is in-accurate! Grrr. So the next course of action? Power on my laptop and search for a solution.

Finally, I found a line indicated in another Hitachi aircon unit that to reset this air filter lamp indicator, you'll need to press the louver switch on the remote when the aircon is off. That finally resolved the problem!

This stupid problem delayed my house cleaning schedule by almost 3 hours. Have to cancel all my plans for today. And I haven't had my lunch. :(