Hi all - I am experiencing what seems to be low water pressure, and I really noticed it when I got my lawn sprinklers going this Summer. I have a galvanized tank with what appears to be a volume control valve (see pics), if I am understanding what I am looking at. It is located in a separate well house away from my house. I suspect the tank is from 1956, when this well was dug according to my papers, but I am not sure. The dealer's label on it has only a 4 digit phone number so that makes me it must be quite old. Anyway for the longest time I suspected I had a leak in the irrigation system because of the low pressure, but the pressure problem was not consistent and would affect different zones at different times. After finding no leaks, I started looking at the well. I once saw the valve "spitting," and from the looks of it with the white crust around it it appears to have been doing this a lot lately. Pressure is often around 20, other times it will be around 60 and the sprinklers and everything work great. From what I could make out under the valve it is a Robertshaw.

Anyway from my reading on here I am guessing the air volume control valve, but I thought I would see what some more sage minds might think. Any insights greatly appreciated! I'll add some pics asap

 

To determine if the AVC is the problem, remove it and plug the hole. I have a tank without an AVC valve and it works well for about 30 days before air needs to be added.

 

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The connection between the pressure tank and the rest of the water system might be clogged. This impaires the system operation. A well pump system and pressure tank do not need a volume control valve. The connection should be freely open. In addition the connection between the pressure gauge and the tank and/or the rest of the water system could be clogged and need to be cleared.

Old galvanized pressure tanks work just as well as modern bladder tanks of the same size except that the non-bladder tank needs to be recharged every few months. To correctly recharge a non-bladder tank, turn off the pump and open a cold faucet upstairs and pump air into the top of the pressure tank (Schrader or similar valve provided for that purpose). After the faucet stops delivering water, close it. Continue adding air until you get to a few PSI less than the pump turn on (cut in) pressure. The system is ready for use although faucets when used may spit air every now and then for a few hours or so.

Now, any leaks in the old galvanized tank (or in any pressure tank) need to be repaired or the tank replaced. Soapy water will reveal air leaks particularly near fittings near the top of the tank which in normal operation holds an air cushion. If the air cushion is lost, the entire system will behave unpredictably including showing the symptoms you had.

 

Sounds like I have some troubleshooting to do! In 13 years I have never done anything with the tank so probably long overdue. A few questions, is the Schrader valve under this large nut at the top of the tank? (pictured). Otherwise the only other Schrader type valve I see is down below at the pump (pictured). Another dumb question; if I removed the air volume control valve, would I somehow replace it with just a pressure gauge, if that makes any sense.

 

So just trying to understand what I have here, my understanding now is that the large nut at the top is not the place to access any air charging valve. Still wondering where I should be looking for that and whether there is a drain on or near the tank itself?

 

jaybake32,

Your pump has an automatic air charging system. Down hole on the pump pipe is a tee with a small spring loaded ball in a valve. When the pump is not pumping this ball opens and lets water drain out of well pipe as air enters through the 'snifter valve' (Schrader valve at check valve between well and tank). When pump next turns on this pipe distance (usually 10') has air and not water. The air is forced into the pressure tank and when there is too much air the air volume control opens and lets some of the air out (has a float inside tank). This system provides a constant recharge of air cushion in pressure tank while the air volume control lets out excess air. In a perfect world this is a great arrangement. Unfortunately our water contains dissolved minerals that precipitate out clogging orifices and rendering our controls useless. Apparently your system has clogged drain out down hole and clogged 'snifter valve' (Schrader valve) rendering it all non-working.
Now a good work around would be to acquire a 1/4" tee with necessary fittings and a Schrader valve to splice in the spot between air volume control valve and pressure gauge. You will then be able to "air up" the tank and regain the necessary air cushion for proper operation of pressure tank and pump system.
An occasional air replacement will get you several more years of use from what you have. I charge mine about every three months. ( when I notice pump cycling too often)

Hope this helps.

RR

 

Thank you, although I am not sure I understand where these components are on my system. I've been watching my sprinklers the past few days and it seems that what's really happening now is the pressure just gradually fades out. It starts strong enough at first (right now gauge reads about 44). In a few hours at the last sprinkler zone the heads might be barely bubbling, and the gauge will read right around 20. What I am wondering now is how to drain it properly, and I was planning on changing the pressure switch and the gauge and maybe the air volume control valve since these all appear to be quite old (see pics). I haven't really found a setup like mine elsewhere online so it has been confusing to me. I see two Schrader valves between the pump and tank, but nothing to readily open to drain the tank of water. However, it does look like there is a spigot included in the pipes that come from the other side of the tank. Is that the drain?? And if I am understanding correctly, is there no "air charging valve" as such on my setup?

 

You are correct on tank drain being the faucet from backside.

Can't read the writing you posted on first picture.

RR

 

The automatic pressure tank charging system relies on putting in a small amount of air each time the pump cycles on and off. Apparently that is inoperative now. All of the manual charging methods described in various places in this forum involve emptying out the tank and putting in a large amount of air all in one sitting.

The pressure tank needs an air inlet or vent near the top in order to empty it out, either by gravity with a valve opened down below or by force using an air pump up above. It looks like the only opening near the top is where the gauge is mounted.

Because the task of draining the entire water system before working on the pressure tank may empty out the water heater tank, you should should shut off the water heater heat before starting this project and not turn that back on until everything is completed and water is gushing out of a hot faucet upstairs.

 

Air volume control: How to Find & Repair, Replace, or Remove the Water Tank Air Volume Control

https://www.plumbingsupply.com/wellpart.html

Here are two links to explain the air control process.
On your system I see a gate valve in well pipe just at the well cap. It has no handle. These are installed to choke down pump flow to prevent over-pumping well capacity. Possibly it needs tightened a half turn to reduce pump flow in gpm.

When you replace pressure switch, also replace the small (1/4") pipe and fittings leading to it. They have a tendency to clog with rust an/or mineral deposits and not let the pressure switch get a true reading.
Just passing along some of my experiences these last 50+ years.

RR

 

Thanks guys this is starting to make more sense to me. From the looks of things I am thinking my system is a bit less common than most? I am going to attach another image here, basically the things the arrows are pointing to are what I am trying to identify at this point - what their purpose is and if there is anything I should check at those points. Sorry the text is hard to read. My understanding at this point though is that draining the tank in order to work on the components would not also involve any re-pressurizing on my part, as that is "automatic"?

 

jaybake32 Rough Rooster is giving good advice

FIRST...........................you need to deside if the tank is full of air................OR ..........water

tap on the tank........the air will be hollow ...............the tank will be cool below the water level and warmer above


the air volume control valve is the first 3 photos of the post

the Schrader valve is the little tire tube looking valve in the large brass check valve next to the tank in post 8

YOU HOPE one or both of these parts are bad.............................because you can buy them for under 20-30 bucks and change them yourself.

the other part that could be bad is the bleed valve located 10 or 20 feet down in the well.

LET US HOPE for an easy fix.

hook a hose to the faucet from backside.............run it somewhere that will take a tank of water..................

turn off the pump(if this well supplies a water heater..........turn it off until you are done)

with the pump off..................turn on the faucet.............

put a rock...block....on the end of the hose so it will not jump around when....if.....air comes out.


WATCH WHAT COMES OUT OF THE HOSE

IF YOU GET A LITTLE BIT OF WATER and A LOT OF AIR ..........

i would say that the air volume control valve is bad and needs to be replaced.

IF YOU GET A LOT OF WATER and A LITTLE BIT OF AIR ..........

you might have to crack(unscrew) the air volume control valve to get all the water out(to let air into the tank)

it is a bad Schrader valve AND/OR the bleed valve

one is easy......................one is hard.............change the Schrader valve and HOPE......i might even pray



if i had to run to the store...................i would replace both the
air volume control valve and the
Schrader valve.....................buy a fresh tube of pipe dope


the air volume control valve needs a large pipe wrench.

the Schrader valve takes a small wrench and unscrews out and up out of the large brass check valve

both need pipe dope when you replace them

replace both of these parts and it may fix everything.

OR

IF YOU GET LOTS OF AIR WHEN YOU BLEED THE TANK

let all of the air out

close the faucet.................turn on the pump

the well should work great for 1 or 2 months..........until the tank gets full of air again.

if this supplies a water heater .....run hot water in a sink.......make sure the water heater is full of water and not air.

if you turn on a water heater without any water the elements will melt

if you replace the two parts and everything is working correctly

the air volume control valve should let air out every so often just before the pump comes on.

when the pump comes on(after being off for 5 or maybe 10 min.)
you should hear a short burst of air going into the tank.

the pump must be off for a short time to give the bleed valve time to let the water out of the drop pipe.

if you replace the 2 parts and the well does not pump air and come out of the
air volume control valve you will have to bleed the tank every month or so..................................

OR

PULL THE WELL DROP PIPE 10 OR 21 FEET AND REPLACE THE BLEED VALVE.

imho.....................ymmv

 

Yes I greatly appreciate all the advice here, my only worry is making sure I understand what the heck I am doing before I plunge into trying to fix anything lol. Thank you for all your guidance this was very helpful. I did drain the tank, and, for the first 30 seconds or so it was mainly air coming out. Then, I'd say about 20 minutes of steady water. The last 3 minutes or so was mainly air. Having not done this before, I am not sure if this would be considered lots of air, or lots of water.

When I turned the pump back on, as it was refilling, I noticed the Schrader valve that is close to the tank started to drip. Not lots of dripping, but noticeable. It has now stopped dripping. So of course I am wondering and hoping that this simply means I need to replace the Schrader valid.

I'd love to test the sprinkler system but cannot. I decided to turn off all the power to the house just to be safe. I threw the main switch in the basement but when I went back out to the well house, the light and pump and sprinkler timer were still on. This really puzzled me until I noticed a small box on the utility pole where electric come in, and right below the electric meter is a sub-panel box. I threw those switches and everything in the well house went off finally, but now only the well pump comes back on, not the sprinkler controller. The switch feels soft and I am sure just needs to be replaced, but because I cannot kill power to this sub panel outside by turning off my main panel in the basement, I am obviously reluctant to try and change the breaker in the subpanel. Maybe I should take that question to the electrical forum...

 

Having some trouble finding a replacement "snifter" valve, it seems that everything is a schrader valve. Any guidance appreciated!

 

Here are two on Amazon.

Robot Check

RR

 

Would that be the first two on that link, or the second two? I ask because the first two look like simply schrader valves with caps, the second two look more like what I might need, although, the first two are labelled as "snifters." Surprising how confusing this is lol!

 

Snifters have a weaker spring on the valve core. Only difference.

Schrader valve will not replace snifter, but snifter can be used in place of Schrader.

The top picture is a 1/4" pipe thread and the second one is for 1/8" pipe thread.

RR