Writing can be a great escape. When difficulties arise at home, it is a pleasure to be able to say, “I’m sorry, but I have to write,” and walk out of the room, leaving my family to their fate.

Often, however, I find myself praying for the arrival of a problem that will enable me to stop writing. This is the mood I’m in when I pass the open door of the downstairs loo and notice the toilet cistern lid has been removed and laid across the bowl – the international signal for Do Not Use.

“What’s happened here?” I say, trying not to sound too delighted.

“It won’t stop flushing!” my wife shouts from her desk.

“Just jiggle the handle,” I say. I invented this solution months ago, and am frustrated it hasn’t been more widely taken up.

“That never works for me,” she says.

“There’s a technique,” I say. “You just have to…” I stop there, because I notice that jiggling isn’t working for me either. The toilet keeps flushing. I move the lid aside, light the torch on my phone and think: there will be no more writing today.

It is clear that in the years since I last peered into a toilet cistern, the technology has moved on; I don’t recognise anything. In our old house, I once repaired a broken flush mechanism with a D string from a guitar, but nothing as agreeably primitive will serve here. Everything is modular, and plastic, and sealed.

I turn my phone around and search until I find an eight-minute video of a plumber replacing what looks like a similar system. About four minutes in, he suddenly pulls the toilet tank off the wall, and I hit pause. I’m not doing that, I think. I’d rather write.

Unfortunately, I have been obeying his instructions so far, and as a consequence I’m holding the main portion of the flush valve unit in my left hand. The toilet, which had been merely trickling, is now gushing. The plumber in the video had taken the precaution of turning off the mains water first. I ignored this bit, because I don’t know how to turn off the mains water.

I fetch my toolbox. Holding a pair of pliers in one hand and a long screwdriver in the other, I stare into the cistern for a long time. Finally I get an idea: I push the point of the screwdriver under the float valve, letting the handle hang over the edge of the cistern. Then I balance the pliers on the other end of the screwdriver, like a fat man on a seesaw. Its weight is sufficient to lift the float and shut off the intake. The water stops. I show both palms to the pliers in a manner that says: stay.

Sitting down at the kitchen table with another screwdriver, I take the valve unit to pieces, breaking it even more in the process. When it’s beyond repair, I stop.

“Now, it doesn’t work at all,” I tell my wife.

“Do I need to call a plumber?” she says.

“Not yet,” I say. I go back online, and find what appears to be the exact same valve unit. I gamble £28.

The next day feels like my birthday. The package doesn’t arrive until 5pm, by which time I am a little overexcited. I open the box, and hold the new unit up to the old one. They’re exactly the same. They’re even the same colour.

The repair, in the end, is anticlimactic. The unit basically snaps into place. It takes seconds. Also, I had sort of imagined my family gathered round the toilet at this moment, watching me, perhaps applauding. But I’m the only one home.

Half an hour later, when I hear the front door open, I stand up from the kitchen table. When the youngest one walks in, I am holding the broken unit in front of me.

“What’s that thing?” he says.

“A dual flush toilet valve,” I say. “I just replaced it.”

“Nice,” he says.

“The base unit was fine, so there was no need to remove the cistern,” I say.

“You don’t need to walk me through the whole process step by step,” he says.

“I’m afraid you’re wrong there,” I say. “Please sit down.”