I was welcomed home to a pressure tank that wasn’t quite working. The well pump would turn on ever 20 seconds or so while taking a shower for example. When I went down to look at the pressure gauge, it would pressure up to 50 PSI, and as soon as water came on via a tap or washing machine or something, the pressure would plummet! Quite visibly which isn’t good.
So I started googling it a bit, and there was talk about it being waterlogged (similar symptoms to what I was seeing). It gets a bit complicated here on in, well not complicated, you just need to have more info about your tank than I had. There are tanks with bladders in them which separate the water and air and tanks without bladders – which I came to find out was what mine was. Mine is an older fiberglass pressure tank, its large. Like 30 gallons large or something.
Here is a site that describes some common issues related to short cycling.
My issue was that the air valve was not working at all, nothing came out and I couldn’t blow air in. So I took it out, wasn’t too corroded, but there was a lot of mineral blockage causing it to be completely plugged up preventing me from getting air into it. Once I had that out, I was able to fully drain the tank. I dumped several 5 gallon buckets worth of water down the drain that came from it. It was almost full of water – which is not correct, there should be a large pocket of air in there. The air is there so that the pump actually has something it can compress (water doesn’t compress, well it does, but its super hard and for all intents and purposes doesn’t compress). Once completely drained, the pressure tank had zero PSI (newer tanks with a bladder will retain some pressure in them called ‘precharge’. It runs from 20psi to 40psi normally. I plugged in my compressor (its a standard bicycle tire sort of valve stem so you fill it up just like a tire. I put in 20 pounds and proceeded to open all the valves again and turn on the pump. This time the pump took a good while to restore all the water and get it up to 50 PSI again (the preset cut out pressure on my well pump – but this is adjustable as well). Now when a tap is on, the pressure goes down so slowly as to not be noticeable. And when it does come on, it takes a good minute to fill which is what you want. The pressure / water should last for a good while before the pump comes on and you want the pump to be able to run for a minute to a minute and a half (duty cycle) so that its not switching on and off all the time.
My tank runs like new now! Its a simple process really to recharge this, definitely recommended that you try this before going out and buying a new unit! A little effort saves literally hundreds of dollars on new hardware / plumber time! Just google this stuff, lots of info on it.