I think you are arguing on different topics and therefore, will never make perfect sense, even if you spend the next 4 Friday. After all, Gas Boiler Explosion - Mok-Dong,Seoul, Korea is about best gas boiler. Just my 0.02$.

I had been searching for someone to prove this point about of gas boilers for a little while, actually I have been searching since last Monday, as, as you know, a lot of posts or should I say all posts except the ones on: How to service a gas boiler DIY, are promoting the opposite position, so I'm glad I found this.