Dear Folks,

Iím new to the forum and would appreciate your help. Iíve searched the posts here but Iím still confused, so thought I would provide my situation and details in hopes someone could lend insight.

I am in central Florida, and have a home built in í67 which I bought in 2000. 335í well with an AO Smith C48K2FC11 [R1072] 3/4HP 3450 RPM, 230V, 7.4 amp vertical pump mounted next to a steel water tank about 20Ē wide and 64Ē high so I estimate ~80 gallons; and a Brady AR45 Air Volume Control in a very small pump house in the carport. Thereís no condensate or marks visible on the tank. No water or air leaks that I can tell. Pressure isnít as high as Iíd like at the kitchen sink due to the wonderful faucet flow restriction, but itís pretty good in the two showers; even quite hard in one. I have a Square D 20-40 Water Pump Pressure Control Switch about three months old I had to replace because its contacts plain wore out and broke into pieces. Could have been original from the looks of it. When I put the new one on, it came on at 20 and off at 40 with no adjustment required.

Iíve replaced the old, original faucets inside and out and the water heater since moving in. Iíve always felt the pump ran too short since we moved in, mainly just from the size of the holding / pressure / galvanized tank. The pump would come on from 8 Ė 10 seconds, off for about 35 when the waterís on full at outside faucets or if the washerís filling, or a shower running.

I noticed the gauge indicated the pump was coming on at 20 and off almost immediately at 25 rather than going to 40 when the washer was filling. I figured the tank was saturated with no air in it, so I shut off the main valve into the house, turned off the pump breaker, opened the tank drain valve with an 8í hose attached and drained it. Took about 10 minutes running with good flow at first, and gradually diminishing to a trickle, then dry. Began hearing air coming in through the AVC, moistened my finger and tapped the little air intake on the AVC to feel the slight vacuum while it did so.

When the air going into the AVC was barely audible, I turned off the drain valve, turned the breaker back on, and filled the tank, which took about 3 minutes. Still shut off at 25psi on the gauge. I turned on the drain hose and while the pump cycled turned the small spring set screw (high pressure cutoff) clockwise until I thought I was going too far, but never got it above 35. Changed the larger spring (range) until I got it up to 40, but it would come one at 25. Bounced between the two to no avail.

I shut off the breaker and drained the tank again, which again took about 10 minutes. I listened and checked the AVC again, which again let air in for a while. Shut off the drain, fired it back up and it again took about three minutes. Gauge indicates pressure still comes on at 20 and off at 35, with swings in range per adjustment of the range nut/spring.

The pump comes on for about 5-6 seconds, off for 35, then on, then off. Seems to come on 2 Ė 3 times for a 5.5 gallon toilet flush. It seems this setup should be much better than what it is. Is it possible I have too much air and not enough water? Perhaps I should have a bladder or diaphragm pressure tank to keep the pump running longer and reduce the short cycling. I'm stumped as to the pressure changes and increased frequency of cycling. If I have to add a tank I'll pretty much have to remove the pump house as there's no room, and I'd rather have a clean straightforward system than one with pipes running through walls out to a diaphragm tabk and back again... In the meantime, can anyone offer any suggestions?

Thank you very much for your time and help in this matter.

Best Regards,
Chuck