Blue_e, Not wanting to get your unit professionally serviced is really not an option, it MUST be professionally serviced based on Qld requirements, which are over and above any national requirements/recommendations.
Interesting you didn't mention the wind rating regardless of standards etc. In windy conditions with some of those low rated units one may as well pi.. into the wind, which would do a lot more good than some ext.
Nq, #
now why would I tell you that Halon (BCF) is unfriendly to "that" hole, I wouldn't do that #
Cheers, Kerry.