Well looking at Heathrow Airport again; the max temp has been 25C+ for most of the past two weeks and for almost a week at the start of the months, a couple of days in June and no days in May. So not really that sustained and not that much different from last year. The only significant difference is a run of a week of 30C+ temperatures this month.
And your last sentence says it all - 30C+ is not normal in this country, is it? Not that 25C+ happens that often for extended periods either, as your figures show.
I'm sure they are doing their best with what they have, but it isn't being maintained - it doesn't work!
I wasn't complaining about the air conditioning up until 3 weeks ago no, because it wasn't hot enough for. Disagree with the windows usually being shut too, normally they are open - because the a/c isn't working.
Agree with your last paragraph though.
Make your mind up. Are they maintaining it or not? You manage to have it both ways in one sentence. I think you seem to be saying that up until the hot spell started, the system was doing its job.
How the windows are normally open on the 166s you use, I'm not sure, because FGW recently removed the handles and locked them. They may have unlocked them again in anticipation of the heat and just relied on the seals to keep them shut most of the time but the intention is clearly to operate with the hopper windows out of use except in a case of system failure.
And if people are being allowed to open windows by themselves again, then that is very likely contributing to the failures, as the blast of air blowing in just confuses the system so much it sits down and dies - same as it did with the old kit. There is a reason air-conditioned spaces need to be reasonably well sealed up.
I repeat, the original 166 system was a lash-up, added as an afterthought to the 165 design and built to a budget. In order to try to do something about it fixing it, FGW had to send a set away to Wabtec so they could crawl all over it and come up with a way of doing the work that didn't involve tearing the trains apart - which inevitably will have involved more compromise.
As I said previously, there is clearly still an issue when temperatures get to the high 20s and beyond. And FGW will be trying to address that problem, same as the staff at Reading depot will be trying, in the limited time they get each night, to get the a/c systems serviceable again.