I suppose there’s one benefit to having a knackered heating system – it requires lots of testing, to work out what’s wrong with it. It’s quite nice sitting in a roasting hot house during the day, under the guise of “testing” my heating system works.

Or in this case doesn’t. The water keeps trying to escape. The boiler man came yesterday, it’s the same bloke who does the gas inspections, and we had a bit of a play with it. Of course, since he was there things worked better than just me being there. We discovered that the boiler pressurises the system up to 4 bar quite happily, which is bad – it should only go to 2 bar. Above 3 the safety relief valve should open and send hot water outside through a little drain pipe. Sure enough, dribbling down the wall outside was some very hot water, and the pressure started to drop.

For the rest of the day it remained at around 2 bar and all seemed… better. Some seals have worn, causing leaks but maybe the expansion vessel isn’t knackered so the boiler shouldn’t need to come off the wall.

However…

This morning I go to the boiler and there’s no pressure again. Yesterday we thought that maybe the pressure gauge was faulty, so I turned the heating on anyway to see what would happen. A fair amount of glugging, slurping and swishing noises confirmed that no, there was not a lot of water left in the radiators. The boiler then switched itself off and instead of flashing the stupid green light of “I’m OK” it lit that constantly and flashed a red light of “something is wrong”.

Well that’s good, my concern about the boiler exploding due to over pressure has gone. And now I know what happens if I try to light the boiler when it has no water in it. So at least I won’t come home one day to find half my kitchen wall missing.

So, best fill the radiators again, back to 1 bar. This took ages, and was accompanied by little whistling noises as the air-release valve opened to vent the air in the system. This valve is supposed to then close again (or get wet and swell shut) to stop the water coming out too. No, it didn’t, did it? Water started to drip, then slowly dribble out the bottom of the boiler and it’s still doing it now. The other leaks have decided to join in too.

Oh, and the pressure went up to 3 bar, but is now dropping back down again. It’s now at 1.5 bar. I will monitor it over the weekend, then ring the plumber back on Monday to let him know what’s going on.

When I buy a house of my own I’m either going to take out boiler insurance, or learn how to fix it myself.