The boiler had been playing up for a while, slowly losing water through the AAV which was so limed-up that I couldn't budge the vent-plug, and thus necessitating a temporary shift to "top it up now and again" mode until I got a round tuit.
A week or so ago I had a quick chat about it with a boiler-fitter who just happened to be next-door installing a new burner, and during one of his many tea-breaks he popped over and had a quick look at the mess to confirm that a new AAV was indeed required. Furthermore, he told me exactly which tools I would need and which bits would have to be removed in order to get the necessary "great big feck-off wrench" around the offending part, which is right at the back of a 2" gap twixt flame-box and outer-casing - not exactly the most accessible place to put a user-serviceable part. OK, you can get a hand on it to adjust the vent-plug, but there's no way you could get a spanner to it. The cost of this professional advice? Nothing. He wouldn't even have a cuppa.
Anyway, I got hold of a replacement part, gathered a box-full of assorted wrenches, spanners and stillys, and waited for the end of the recent cold-spell.
Yesterday dawned warm and fair, and I judged it to be a good day to start the boiler-hack. I followed the bloke's advice to the letter:
- turn off the power, gas and water supplies - a 5-minute job
- drain the system to a level well below the boiler - a 10-minute job
- remove the outer-casing - a 1-minute job
- remove the fan assembly - this was a pain in the ar5e. 3 of the 4 screws had seized and needed to be drilled out after I'd mangled the screw-heads by forcing them too hard. I wasted nearly 2 hours on this bit.
- remove the fan assembly base-plate - not so bad, only 1 screw had to be drilled out. 20 minutes.
- remove the air-pressure switch mounting plate - another 5-minute job
- remove the collector hood - ten minutes for this, no knackered screws but a bit fiddly
After all that fecking-around, I had a well-earned brew. Mug in hand, I looked at the selection of wrenches and eyed-up the offending part. Reaching in to check that there was no obstruction behind the AAV, I gave the thing a casual twist by hand... and it moved! B@stard! I unscrewed it more and more until it disengaged. B@stard! B@stard! B@stard! I could have just reached in and unscrewed it hours or even days before without all that sodding disassembly.
Needless to say, the new bit was fitted and the whole shebang was put back together, tested and running just fine and dandy way before I stopped swearing.
B@stard.
Actually, that previous sentence is incorrect. It's now eight hours later and I've not stopped swearing yet. A lot has happened during those eight hours, not least the formulation of a plan to insert that "great big feck-off wrench" sideways up somebody's rear-vent.
And the moral of this story is... ?
