Well pump cycle time is decreasing
#1
01-08-13, 04:22 AM
Well pump cycle time is decreasing
When under high-volume loads (filling a washing machine, for instance) my well pump used to run for about 5 seconds then rest for about the same time, then repeat. After 14 years, I wonder if something is wearing out. Now it cycles on for about 2-3 seconds, and rests for 2-3 more, etc...
What are areas I could check?
What are areas I could check?
#2
01-08-13, 04:38 AM
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You need to check the reading of the pressure tank.....it may be too low.
First.....determine what the cut-in pressure is for your pump. Open a tap and watch the pressure gauge and note at what pressure the pump comes on.
Next.....turn off the power to the pump and drain all the water out of the pressure tank. Next.....there should be a schrader valve on the top of the tank similar to a car tire air valve. Check what the pressure is in the tank at that valve with a tire gauge......it should be 2 psi lower than your cut-in pressure setting on the pump. You can add air if needed with a bicycle pump.
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You need to check the reading of the pressure tank.....it may be too low.
First.....determine what the cut-in pressure is for your pump. Open a tap and watch the pressure gauge and note at what pressure the pump comes on.
Next.....turn off the power to the pump and drain all the water out of the pressure tank. Next.....there should be a schrader valve on the top of the tank similar to a car tire air valve. Check what the pressure is in the tank at that valve with a tire gauge......it should be 2 psi lower than your cut-in pressure setting on the pump. You can add air if needed with a bicycle pump.
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#3
01-08-13, 05:00 AM
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If setting the pressure tank's air pressure like Halton mentioned does not help it is possible that your pressure tank is bad and needs replacing, but certainly go through the procedure first to make sure it's properly charged.
#5
01-08-13, 05:21 PM
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hi Louuuuu and guys -
...my well pump used to run for about 5 seconds then rest for about the same time, then repeat....
#6
01-08-13, 05:33 PM
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Yes.....it is wrong. It's amazing that after 14 years the motor hasn't burned up.
The centrifugal start switches don't usually last that long with that type of cycling.
The centrifugal start switches don't usually last that long with that type of cycling.
#7
01-08-13, 05:54 PM
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I think the O.P. was specifically referring to the pump cycling when the water was being used.
In that case it would not be abnormal for the pump to cycle on and off.
If the pump supply is greater than what is being used.....it would shut off once the cut-off pressure is reached. Then it would turn right back on as soon as the pressure dropped back down to the cut-in pressure. As long as a tap was open.....it would continue to cycle.
But.....if the tank pressure is too low......then the time between cycles is reduced because the stored energy is less......meaning the reduced volume of compressed air in the tank is depleted more quickly.
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I think the O.P. was specifically referring to the pump cycling when the water was being used.
In that case it would not be abnormal for the pump to cycle on and off.
If the pump supply is greater than what is being used.....it would shut off once the cut-off pressure is reached. Then it would turn right back on as soon as the pressure dropped back down to the cut-in pressure. As long as a tap was open.....it would continue to cycle.
But.....if the tank pressure is too low......then the time between cycles is reduced because the stored energy is less......meaning the reduced volume of compressed air in the tank is depleted more quickly.
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#8
01-08-13, 09:27 PM
+1 zoesdad... cycling on/off every 5 seconds is always wrong, whether water is in demand or not. evidently tank is entirely too small or has failed. rule of thumb is a tank with a drawdown that matches the pumping gpm so you get around a 1 minute minimum run time. bigger is better.
#9
01-09-13, 04:57 AM
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Agreed.....they're could very well be another issue.....but if indeed he has a small tank.....then a short cycle would be "normal" for him. Not everyone has the luxury of a perfect set-up. Will need an update from him before making any conclusions. His 5 second reference may have been subjective....simply to describe the decrease in cycle time.
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Agreed.....they're could very well be another issue.....but if indeed he has a small tank.....then a short cycle would be "normal" for him. Not everyone has the luxury of a perfect set-up. Will need an update from him before making any conclusions. His 5 second reference may have been subjective....simply to describe the decrease in cycle time.
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#11
01-10-13, 04:28 AM
New information:
Pump kicks on at 24 Psi
off at 52 Psi
After I drained the tank, there was no pressure reading at the schrader-type valve.
I turned the power back on and refilled the tank. The gauge read 42, and my tire gauge on the schrader valve read 40.
Paperwork for the pump (Well Mate) says that System Pressure Range should be 30 - 50 Psi. And the precharge should be 26.
So, what does this all mean?
Pump kicks on at 24 Psi
off at 52 Psi
After I drained the tank, there was no pressure reading at the schrader-type valve.
I turned the power back on and refilled the tank. The gauge read 42, and my tire gauge on the schrader valve read 40.
Paperwork for the pump (Well Mate) says that System Pressure Range should be 30 - 50 Psi. And the precharge should be 26.
So, what does this all mean?
#13
01-10-13, 05:15 AM
Group Moderator
Bperry is incorrect. The air pressure in the tank should be 2 psi LESS than the pump cut in pressure.
Because the air pressure in the tank will vary with the amount of water in it it's a moving target. So you must check the tank's air pressure when the tank is empty and the water pressure has been bled down to zero (no water comes out of the faucets). Then like Halton mentioned early in this thread the air pressure should be set to about 2 psi less than your pump's cut in (turn on) pressure. So, it you do not change your pressure switch settings you should have 22psi in your pressure tank.
Because the air pressure in the tank will vary with the amount of water in it it's a moving target. So you must check the tank's air pressure when the tank is empty and the water pressure has been bled down to zero (no water comes out of the faucets). Then like Halton mentioned early in this thread the air pressure should be set to about 2 psi less than your pump's cut in (turn on) pressure. So, it you do not change your pressure switch settings you should have 22psi in your pressure tank.
#14
01-10-13, 05:41 AM
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Also.....how old is the tank?.....it's not necessarily bad if it won't hold air.
It's possible that it's a plain tank without a bladder or diaphragm......a couple of pictures of the set-up and any label info would help. We'll deal with the low pump setting once everything else is sorted out. As stated....pump up the air pressure in the empty tank to 22 psi and post back.
To help you better understand what the goal is....see the drawing below. Note the "water level change".....this is the amount of usable water or draw-down available between pump cycles.....and why less air equates to less water.....which leads to the pump turning on and off too often.
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Also.....how old is the tank?.....it's not necessarily bad if it won't hold air.
It's possible that it's a plain tank without a bladder or diaphragm......a couple of pictures of the set-up and any label info would help. We'll deal with the low pump setting once everything else is sorted out. As stated....pump up the air pressure in the empty tank to 22 psi and post back.
To help you better understand what the goal is....see the drawing below. Note the "water level change".....this is the amount of usable water or draw-down available between pump cycles.....and why less air equates to less water.....which leads to the pump turning on and off too often.
.
#15
01-10-13, 07:00 AM
Thanks for the advice, everbody.
Tank is about 16 years old. Hopefully, it's just a normal leak-down over time...
I hope to get it pumped back up this evening.
Tank is about 16 years old. Hopefully, it's just a normal leak-down over time...
I hope to get it pumped back up this evening.
#16
01-11-13, 04:12 AM
The problem is solved! (At least, for now.)
Thanks for all of the advice. I looked further into the "waterlogged" tank, and it all makes sense.
I put in 25 psi of precharge pressure. Now it runs like it did originally.
Next questions:
- I assume this condition is not uncommon. What check/refill interval would indicate a problem? 1 month? 6 months? 1 year?
- If there is, in fact, a leak - Can I replace the bladder, or does the entire pump get tossed out?
Thanks for all of the advice. I looked further into the "waterlogged" tank, and it all makes sense.
I put in 25 psi of precharge pressure. Now it runs like it did originally.
Next questions:
- I assume this condition is not uncommon. What check/refill interval would indicate a problem? 1 month? 6 months? 1 year?
- If there is, in fact, a leak - Can I replace the bladder, or does the entire pump get tossed out?
#17
01-11-13, 04:50 AM
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We'll try for the easy one first.....check if the schrader valve has a slow leak.
Cover the top with some spit or a dab of liquid soap and see if any bubbles appear.
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We'll try for the easy one first.....check if the schrader valve has a slow leak.
Cover the top with some spit or a dab of liquid soap and see if any bubbles appear.
.
#18
01-11-13, 06:10 AM
Group Moderator
There is no repair for a bad pressure tank. Even if the bladder is ruptured it will work and that's how old pressure tanks used to be, just a tank with no rubber bladder. Luckily pressure tanks are relatively inexpensive if you do need to replace yours.
#19
01-26-13, 08:32 AM
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Louuu, just so you know. If you have a bad pressure tank and you drain it, set the pressure right and then refill it, it will appear to fix the problem (if you have a good pressure tank it will fix the problem). However, in a waterlogged pressure tank the air, in it (the air you so diligently pumped into the shraeder valve) will over the next few days, dissolve into the water and dissappear.
So. All that being said. If your problem comes back in a week or so. It's time for a new pressure tank. As someone here has mentioned. Bigger is better. Get the biggest pressure tank your space will accommodate. Your pump will thank you.
So. All that being said. If your problem comes back in a week or so. It's time for a new pressure tank. As someone here has mentioned. Bigger is better. Get the biggest pressure tank your space will accommodate. Your pump will thank you.
