The design and location of the engine block coolant drain should be nominated for the Schnabel prize
Also, the system flow design makes complete flush difficult
Therefore, many owners are just draining and refilling radiator only.
The manual gives 3.7 L drain/refill capacity (with recovery tank) and 5.3 L total capacity for a/t
Draining radiator only yields about 2.3 L
Based on calculation, draining/refilling radiator 2 times (with full heating/cooling cycle between the changes) will give almost equivalent coolant "refreshment" result without draining the block:
2.3 L of new coolant (first fill) / 5.3 L of total capacity = X L of mixed in new coolant / (5.3 - 2.3) L remaining in the system after the second drain
Finding X gives 1.3 L of new coolant (mixed) remains after the second drain
After adding 2.3 L of new coolant (second fill) calculating the new coolant /old coolant ratio:
(1.3+2.3) L / 5.3 L = 68% which is reasonably close to the old/new coolant ratio achieved after draining block and radiator combined

 

Pre-mix the water and antifreeze in a 5 gal bucket.
Drain the system (Make sure and disconnect the hose that heats the throttle body)
Refill the system until coolant comes out the throttle body hose.
close everything up and run the engine and follow the instructions about bleading the air.
TIP: a dose of one of the products like Blue ice or watter wetter will help expel air..
I do this annually ,, avoiding radiator issues is worth it to me.

 

I use genuine Honda-2 coolant so not needed adding water!

 

What does it mean when the coolant light is on in my 07 fit? It goes away after a while.
I did fill the expansion tank and topped the radiator off.
I head some bubbling or water noises coming from behind the dash/cowl area few times and it was idling.

 

Blue or red light?
Red light means overheating! Keep the heater on full blast until you find a problem.
Make sure that both fans are running (may need to switch a/c on with engine warm)
Also check the fuse #10 (7.5 A) in under dash box

 

I should have checked the manual haha. Its the low temperature warning, which makes sense that it goes away after the coolant warms up.
Never had a car show that before so i was confused. Usually its the gauge dial that shows coolant temps.

 

These are the great news!!
Overheating engine in modern car is the worst thing to happen