water pressure cycling

[randy41]

my water pressure cycles up and down more than i would like it to. i have a small pressure tank. would a bigger tank help to even out the pressure? is there another way to accomplish this?

 

[RobertN]

Have you checked the pressure on the air bladder in the tank? Those have to be checked and air adjusted, just like tires.

 

[Gary51]

You may be interested in a cycle stop valve:


Cycle Stop Valves, Inc.

 

[turnkey4099]

my water pressure cycles up and down more than i would like it to. i have a small pressure tank. would a bigger tank help to even out the pressure? is there another way to accomplish this?

Yes, a bigger tank will make the cycles longer. You can also get a constant pressure controller. I've never had any experience witht them.

Be sure to check your precharge pressure int he tank. Drain it completely and check. Pressure should be 2 psi below whatever cutin pressure is.

Short cycling - rapid cycles between cutin/cutout pressure can destroy a pump in short order.

Harry K

 

[clemsonfor]

We were in a moutain rental house over thanksgiving in boone,NC. This was a $250-300K house build on a million dollar lot. The shower would go from normal pressure to if you had the toilet running on the low side it would all but cut the shower diverter off from so low of pressure. It was about 2 mins between normal pressure and so low that without anything else running it would barely leave the shower head, then slowly back up to pressure.

This is no solution but they definitly had a problem as well.

 

[Kays Supply]

The constant flow valve is basically a pressure regulator. If you can't do it, hire a local pump guy to install it. I put them on all submersible systems. Not many jets anymore in my area. Jacuzzi had the first one and it was sweet. It actually had a valve that blocked the switch until flow stopped.

 

[Mickey_Fx]

See some are making assumptions. Up until last yr our previous place didn't have a captive air tank. Lived there for 40 yrs and still using same tank that was there when we moved in. If your's isn't, the short cycling is a sign of the tank being water logged. Had to recharge our tank several times a yr to keep the short cycling in check.

You've not given any specifics about your water system so is impossible to give any good advise, just guesses.

How big is the tank? Drawn down capacity or total capacity? Is the pump cycling even with the faucets off? If so, that a sign of a leak somewhere in the system.

 

[mmurphy]

Here is a site that is real good on these type of problems. Pumps And Tanks Forums!
They have plumbers, well drillers, and sales members that are real good at reading the info you give them.

 

[Mickey_Fx]

Thanks for the link Mark.

 

[randy41]

I think the tank is 20 gals. its not marked but its about 16" in circumference and 24" high. the switch is a 30/50. It doesn't rapidly cycle (not sure how rapid is the rapid you refer to) and it holds pressure when no valves are open.
i looked for a cycle stop valve in lowes but didn't see one. thanks for all the suggestions. I'll also check the tank pressure tomorrow.

 

[flyingcow]

Have you checked the pressure on the air bladder in the tank? Those have to be checked and air adjusted, just like tires.

go for this first. Bladder may be bad.The overall size of the expansion tank isn't as important as bladder working right.

 

[Mickey_Fx]

I think the tank is 20 gals. its not marked but its about 16" in circumference and 24" high. the switch is a 30/50. It doesn't rapidly cycle (not sure how rapid is the rapid you refer to) and it holds pressure when no valves are open.
i looked for a cycle stop valve in lowes but didn't see one. thanks for all the suggestions. I'll also check the tank pressure tomorrow.

If your tank is 20 gal, you only have ~6 gal draw down. IMO that's not very much if this is for the complete house. That works out to be a 20 psi drop in pressure about every 60-90 sec depending upon number of faucets are open at same time. My tank is 80Gal with a 25 gal draw down. With one faucet running full on, can go something like 5-6 min between cycles. Maybe over kill but continual cycling of pump is hard on them. Much better to have larger tank so pump cycles less frequent.

 

[JamesHW]

At our rural place we have a pump and expansion tank in the basement which I drain every season to winterize the place and noticed thislast spring the pump was cycling frequently as if water was runnng. I checked everywhere and couldn't find any leakiy taps or pipes and was somewhat stymied. My best pal came over to assist with draining some bottles of beer and he suggested I might have an air leak before the pump and sure enough, where I hopoked up the pump to the pipe coming through the wall I had not tightened the hose clamps and there was a tiny air leak where the pump was sucking air in addition to the water. Tightened that up and the problem was solved.

 

[Pete Judd]

I have the well pump set to pump 5 gal a min. But have a 80 and 120 gallon captive air tanks. The reason for the large tanks, is that I have to supply 2 houses from the same well. With the two tanks pump run time is a few min and the deep well pump is over 20 years old. The way I look at it, can't have to much storage. It is a PITA though when we loose power, and I have to hold the low pressure switch long enough to fill the tanks.