My Cup Runneth Over

Although it has not rained in any effective manner for eleven days, my underground rainwater tank is full, actually overflowing down the exit pipe. The sound of running water percolates into my consciousness late at night as I stroll round the garden with the dogs. All is clearly not as it should be. It becomes clear that, for no discernible reason, the emergency top up from the spring is running full tilt into the tank.
I have a choice, no hot water or serious water wastage. I compromise and turn of the power for the night. The gurgling is silenced.

Fortuitously the next day my electrician is already booked to fit a new pump, which he does with his customary efficiency. Come switch, on all is silent. It transpires that the pressure gauge which has been warning that the water level is dangerously low, thus triggering the top up, has now pulled up the drawbridge and expired.
On ringing the makers I am ecstatic to be told that the manufacturer of this vital part has gone out of business and that the replacement part is not compatible with the existing circuitry, and anyway they have none in stock but are expecting a delivery any day from Ireland!
Estimated cost of replacement parts is £700 plus, naturally, VAT.
By some mysterious jiggery poker, a lash up, short circuiting the probe, eventually leads to a resumption of hot water supply. How long will that hold I ask the electrician, "Oh about ten years" comes the reassuring reply. We will see!.