> Just a "combi" boiler with the central heating pressurised to about 1 > atmosphere, which I suppose is pretty normal. Over time the pressure > drops and one has to raise it by opening the system to the main. In the > old days you'd have a sturdy brass cock to turn open until the pressure > was right and then close. This is now forbidden and is replaced with a > slotted screw, which one has first to find, then get a screwdriver > that's long enough to get past the pipes that are in the way. You then > have to hold the tip of the screwdriver in the slot so that it doesn't > wander, while tuning the rather stiff screw a quarter of a turn, and > back again when you're finished. If you don't fully close it, which is > easily done, then slowly the pressure in the system will rise to mains > pressure, probably leading to leaks and even bursting the heat-exchanger > and flooding the house. No doubt if I read the regulations I'd discover > that I ought to take nil by mouth for 5 hours before the operation and > wear goggles and a safety belt to British Standard 5908-b. > > JD On this part of the planet, pressure in this type of (typically commercial) system is maintained automatically through a diaphragm regulator. No personal armor or tools required to schedule an annual maintenance inspection. Ron N
This PTG archive page provided courtesy of Moy Piano Service, LLC