Pressure tank cycling 30 minutes after any water is drawn...

[HollyAR75]

Hello, first post here although I've read through quite a bit of the forum for the past year.

We have a low yield well that is connected to a 550 gallon cistern for storage. Our pressure tank is under the house in a crawl space so I can hear it when it cycles. Last week, everyone else left for out of town so I've been by myself, probably using 25 gallons per day only. One thing I've noticed is that after I use water (for example to do dishes) , I hear the pressure tank cycle 30 minutes later. It won't cycle again at all so i don't suppose it's a sign of a leak but I've never before noticed a cycle from it being so much later after using water. I think it's maybe a 10 gallon pressure tank, it's not very big. There is no problem with the water, everything seems to be working fine, except for the 5 years that I've lived here, I've never heard it cycle unless water was being drawn, not a half hour later. Any ideas?

 

[Valveman]

After you use water check the pressure gauge. With no water being used for 30 to 60 minutes the pressure should stay the same. If the pressure drops when no one is using water either you have a leak or the check valve is failing.

 

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[HollyAR75]

Thanks for the reply Valveman. So is it normal for the pressure tank to cycle 30 minutes after using water? For example, it cycled about 30 minutes after I used water for dishes last night at 7pm and then it didn't cycle again till I woke up this morning and used water. Is it ok as long as I'm only hearing it cycle cycle within 60 minutes of water being drawn?

 

[Valveman]

The pump only comes on when the pressure drops to the pressure switch start point. The pressure should only drop when you are using water. If the pressure drops and the pump comes on when no water is being used, then water is leaking somewhere.

 

[HollyAR75]

The pump only comes on when the pressure drops to the pressure switch start point. The pressure should only drop when you are using water. If the pressure drops and the pump comes on when no water is being used, then water is leaking somewhere.

Right, which I've checked everywhere and can find no leaks, but if it was a water leak, wouldn't the pressure tank cycle other times, however it's not. It will not cycle all day or night if I don't use water.

 

[Valveman]

The little nipple to the pressure switch could be clogged. But again, the pump will not come on until the water from the pressure tank goes somewhere and the pressure drops to the start pressure. The pressure should be the same as soon as you stop using water as it is 30 minutes later.

 

[Reach4]

As an experiment, after doing dishes, turn off the valve at the pressure tank that supplies water to the house. See if the mystery run happens. While there, note the water pressure.

Do I think this is likely to change things? Not really, but you have a valve in that direction to try. In the unlikely event that this does stop the mystery cycle, the best thing I came up with so far is a mis-operating trap filler. Most houses don't have trap fillers.

If you have a valve from the cistern, you could try that-- but don't let the pump run dry for long.

 

[LLigetfa]

+1 on a clogged nipple or a bad pressure switch. I've seen where mineral builds up in the nipple and/or under the diaphragm in the pressure switch causing a delay. I have taken out the diaphragm to clean it but sometimes it won't come apart without damaging it so a rebuild kit or new pressure switch may be needed.

 

[HollyAR75]

Thanks so much, that mineral build up idea makes sense since we do have a lot of lime in our water. I've put a call into my well guy to come take a look. I'll update once the mystery is solved.

 

[Smooky]

Could also be something simple like a toilet flapper is leaking. The toilet fill valve comes on uses water and over time eventually the pump kicks on. You could have a slight leak somewhere or a failing check valve as valveman suggested.

 

[HollyAR75]

Just to update, the "problem" of the mystery delayed pressure tank cycle was due to a buildup of mineral deposits around the diaphram and nipple. The system we have setup is 4.5 years old so it will probably be a maintenance issue every 4.5 years or so I'm guessing.

 

[Valveman]

Put the pressure switch at the top of a 2'-3' tall piece of 3/4 pipe. Sediment and minerals would be able to get up there. Actually air will probably accumulate and stay at the top so the pressure switch is in air not water.