Sump pump - runs only 5 seconds?

Maybe you need a different sump pump. Maybe one the you can raise the float switch higher to allow more water in the tank before the pump turns on. When the pump turn on and off in short increments it wears out the motor faster. Also put your check valve a couple of feet away from the pump so you get a good back flush to the pump to clear it. You may need a smaller horse power to work for you. It also a good idea to put some Lysol household cleaner in the tank to kill mold and mildew

The pump has sucked up dirt inside of it, you need to clean it once a year at lease, in some areas more than that, this causes the pump to heat up and the safety relay turns it off because it is getting HOT!  But they do not last very long because they do get plugged up this way.  I clean the one we use on the farm twice a year and they last four or five years for us!  But to clean them is messy to do!  And up plug the pump before you clean it or you could get a finger or two chopped off!

either return it and get a new one under warranty or throw it out and guy a new one . Its  broken and needs a replacement , how old is it 10 years old .

Interesting let it get looked out or return it and get a new one 

ok -- the ball is submerged.  so either the ball is waterlogged and needs to be replaced, or it is sticking on the shaft.  clean the shaft as first step.  second -- when still submerged, manually move the ball up [tie a length of twine to it first so you don't have to put hand into water that might be electrified] -- if that starts the pump, then the ball is waterlogged and you know what to replace.  -- grampa

Your pump kicks off when the float reaches the bottom of the shaft and flips the switch. you have a very short shaft so the pump is only going to operate for that time. If the pit is too small it will empty fast the pump will shut off and as more water rushes in it will cause the pump to cycle on again. Also make you you have a properly installed check valve so the water doesn't just run back down the riser when the pump turns off, which will cause the pit to fill faster and your pump to have to turn on sooner.

Where do you get the idea your pump should run for 25 seconds?  Also get a better brand of pump, those are junk

Get a different pump that allows you to accumulate more water before it switches on.  Or increase the size of your sump so that it will accumulate more water before that pump switches on.  Something is not designed/matched properly.    Call Mastercraft and ask them what is the correct amount of running time per pump cycle.  And how high is the water supposed to be on the pump when it switches on.  You should measure the size of your sump and how much water is in it when the pump switches on, and how low it gets when it switches off.  The difference is the volume of water that is pumped out by the pump.  2 or 3 seconds is like 5 gallons, which seems way too small.  So may be your sump is not designed correctly.

Something is wrong with the float switch.  Have a plumber look at it.

Your pump is short cycling.

To help fix this, raise the pump, so the base of the pump is an inch higher than the lowest inlet or supply.

This way, when the pump turns on, it not only drains what's in the base of the sump (which is what it's doing now), but it will be actively pumping out water that's in the inlet or supply drain tiles too.

I had to do this to mine, and it reduced the cycling from 2-3 five second times a minute to 1 thirty - thirty five second cycle every 2 1/2 - 3 minutes, when it's raining hard.