A bit - switches at less than £2 from maplins and the rubber o ring about the size of a 2p piece in the middle can flatten and I changed mine after 5 years.
I don't bother with a flow controller now either.
So what you are saying Gold is don't bother until something goes wrong. Maybe get a couple of spare microswitches from Maplins and keep them handy.
We have a spare pump in the cupboard just in case. However, we haven't had a single failure in 7 years.
By the way, I have a couple of Maplin microswitches on the cupboard but haven't used them yet as we went onto Varistreams. How do the Maplin microswitches compare to the originals - do they last longer?
12vdc has always been very hard on contact points as opening and closing the contacts creates quite an arch. Has anyone not using a controller tried wiring the pumps pressure switch through the return wire (the black one as apposed to the red) as the electrical flow through the motor reduces or softens the arch.
This was a well accepted practice in the power tool industry with 12 or 18 volt power tools.
I wonder how many have adopted Peter Fogwill's relay system to save pressure switches.
Spruce