Pressure switch replaced, still same, odd problem

Users who are viewing this thread

thewraith

New Member
Messages
4
Reaction score
0
Points
0
Location
dc area
Hi all,

We have an underground well with a pressure tank in our basement. The issue we were having was that the water would run, the pressure would go down from 60psi to 53ish and then the switch would make a noise and the pressure would fall to 5psi. The water would then stop for 30 seconds or so while the pressure would build back up. Same issue, over and over. I changed the pressure switch out, but the same problem exists.

Any ideas what my issue could be or how I could troubleshoot? Any assistance would be greatly appreciated.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Turn off the pump. Drain the pressure to zero by opening a faucet. Measure the air pressure on the valve on the pressure tank using a tire pressure gauge. The pressure should probably be 38 PSI, but it may read zero. If it says 38 or close enough, then the problem would be something other than the pressure tank I think. If it says something more than near zero, then adjust the air to bring the pressure to 38 PSI.

30 seconds? That sounds like there might be two problems... the pressure tank with a problem, and something else.

LLigetfa's thought to measure the current makes sense. If you cannot do that, you could check voltage to prove that the pressure switch was responding. The good news there would be that the nipple to the pressure switch was clogged and was serving as a tiny orifice. The other good news would be that your pressure tank was set wrong. If the voltage comes right away after the pressure drops, the medium news would be that start capacitor in the control box connected to your 3-wire pump was going bad; fairly cheap fix.
 
Last edited:

LLigetfa

DIYer, not in the trades
Messages
7,497
Reaction score
575
Points
113
Location
NW Ontario, Canada
the pressure would go down from 60psi to 53ish and then the switch would make a noise...

The new switch should have a 20 PSI delta unless you changed it. At what PSI do the switch contacts close? The precharge on the bladder tank should be 2 PSI below that.

Check the current draw on the pump when the switch closes.
 

Tom Sawyer

In the Trades
Messages
3,625
Reaction score
34
Points
48
Location
Maine
1 - change the gauge
2 - make sure the line to the pressure switch isn't plugged up
3 - the pressure tank should be charged to 2lbs. Less than the cut in pressure of the pressure switch

If all of those conditions have been met and the problem persists then it's time to do some electrical troubleshooting.
 

thewraith

New Member
Messages
4
Reaction score
0
Points
0
Location
dc area
Man, you guys (and gals) are great! I have some questions regarding setting the pressure tank switch. Note that I have taken Tom's advice above already up to step 3 where I'm unsure.

I did search here, but just want to be sure:

To initially set it at the 2lbs less than cut on pressure, what steps must be taken? I'm guessing:

1. Shut off the water supply to the tank.
2. Turn off the pressure switch via the breaker.
3. Evacuate the pressure w/a hose or by running the water.

The next step is where I'm a little foggy:

4a. Now set the tank to the 36-38psi?
or
4b. You guys tell me :)

I think this is correct, based on reaches excellent post above. I will try this as soon as I get home.

THANKS!
 
Last edited:

Tom Sawyer

In the Trades
Messages
3,625
Reaction score
34
Points
48
Location
Maine
If it's a bladder type tank there will be a shrader valve on it. Use a compressor.
If it's just a tank do all the steps you listed above and once the tank is empty shut off the outlet to the house and turn the pump on.
 

thewraith

New Member
Messages
4
Reaction score
0
Points
0
Location
dc area
If it's a bladder type tank there will be a shrader valve on it. Use a compressor.
If it's just a tank do all the steps you listed above and once the tank is empty shut off the outlet to the house and turn the pump on.

Yessir, it's a bladder type tank w/the schrader valve. To clarify:

1. Turn off the water supply and pressure switch and drain the pressure to the tank.
2. Inflate the tank to 38ish psi.

Correct?

Thanks again.
 

Tom Sawyer

In the Trades
Messages
3,625
Reaction score
34
Points
48
Location
Maine
If it's a 40/60 switch then yes.

If you get water out the shader valve the tank is no good.
 

LLigetfa

DIYer, not in the trades
Messages
7,497
Reaction score
575
Points
113
Location
NW Ontario, Canada
If you get water out the shader valve the tank is no good.

I find that to often be a dubious test. Yes, without a doubt, seeing water come out the valve is conclusive, but on many tanks the valve is at or very near the top of the tank. It is very easy for the tank to be 90% waterlogged and not have water come out the valve.

Draining the tank, adding air, and seeing if it holds the air is a better test but even that can sometimes give false results. A bladder can have a leak yet seal against the port at the bottom of the tank. A drawdown test is more conclusive.
 

Tom Sawyer

In the Trades
Messages
3,625
Reaction score
34
Points
48
Location
Maine
I find that to often be a dubious test. Yes, without a doubt, seeing water come out the valve is conclusive, but on many tanks the valve is at or very near the top of the tank. It is very easy for the tank to be 90% waterlogged and not have water come out the valve.

Draining the tank, adding air, and seeing if it holds the air is a better test but even that can sometimes give false results. A bladder can have a leak yet seal against the port at the bottom of the tank. A drawdown test is more conclusive.

Yep and yep.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks