Low water pressure and volume on community well

[JOHN H SULLIVAN]

Mom lived in a two story house on a community well until she died last year; the well house is sixty feet away. A psi gauge on the galvanized 1" diameter inlet on the first floor reads 66 psi. The first floor toilet, sink, and shower have acceptable volume and one can take a shower for five minutes with acceptable water flow. The upstairs sink has acceptable flow, but the upstairs toilet and shower has very low flow volume. I have replaced the upstairs toilet inlet float valve and cleaned all the fixture aerators. When I flush the upstairs toilet, the psi gauge decreases to 10 psi until the toilet tank fills in about three minutes. The guy across the street, who is on the same community well, installed a well pressure tank on his community well inlet, and he says that it fixed his low water flow problem. This neighbor does not have a booster pump connected to the tank, just the pressurized tank. As most tanks are precharged at 28 psi, I suppose that the community well's 66psi would fill the pressure tank when water is not being used, and when water is being used, the tank's water capacity and 28psi would increase the upstairs pressure and allow a five minute upstairs shower. Before I spend the $400 for a 86 gallon pressure tank, does somebody who knows what they are doing have any insight on my low flow second floor water fixtures? I have spent about three hours on the inner-webs researching this to no avail and although I have installed 20 tanks as a landlord, I really dont understand the basic physics.

 

[Terry]

What year was the home built? Is it galvanized piping to the fixtures? It may be time to repipe some of those.

 

[Sponsor]

 

[Reach4]

When I flush the upstairs toilet, the psi gauge decreases to 10 psi until the toilet tank fills in about three minutes.

Where is the pressure gauge during this?

Try connecting the pressure gauge to an outdoor hose spigot, and repeating the test of water pressure as the toilet tank fills. That should be a better measure of what pressure is coming into the house. If you have no helper to watch the gauge, you could take a move of the pressure gauge with your cellphone.

 

[Sylvan]

I agree with Terry replace the galvanized

 

[Bannerman]

You said you can shower with acceptable flow for 5-minutes. What happens after 5-minutes?

A shower or kitchen sink will usually require a higher flow rate than a toilet. You didn't specify the system pressure while the shower is running or kitchen sink is filling.

Well systems typically operate within a pressure range. 66 psi maybe the pump cut out pressure, so the pump activation pressure will be typically 20 psi lower or ~46 psi. Unless the pump is operating at a higher pressure range and then a pressure regulating valve utilized to reduce the supply pressure to a lower constant pressure to the various homes, you would be experiencing a pressure fall until the pump is activated to cause the pressure to rise again.

You said the incoming pressure drops to 10 psi while the toilet is filling but you seem to suggest the pressure rises again to 66 psi once the toilet is filled. This to me indicates a flow restriction before the pressure gauge. While I agree with eliminating all galvanized pipe, in addition, perhaps your main shut off valve is partially closed.

If main valve is a gate style, the gate may have broken off from the valve stem so the valve will not open fully even as the valve handle is turned to the fully open position. If it is a globe style valve, the stem washer and/or valve seat maybe loose or broken and restricting flow. Suggest replacing those types of valves with a full port ball valve.

Another possibility is a restriction where the pipe feeding your home is Tee'd off from the main pipe leading from the pump house. There will often be a shutoff valve installed there so the same situations as above may exsist.

If a pressure regulating valve is utilized to supply each home, it may not be working properly and therefore restricting flow to all homes downstream.

 

[JOHN H SULLIVAN]

The psi gauge is located within one foot inside the one inch diameter galvanized inlet from the community well. That gauge drops to about 15psi when the downstairs water fixtures are flowing and to about 5psi when the upstairs water fixtures are flowing. As noted above, I have read from other sources that a galvanized replacement re-pipe or well house supply line restriction or leak could cause the flow restriction. Would a 86 gallon tank pressurized at 28 psi with no booster pump increase pressure and or water flow to the upstairs water fixtures?

 

[Reach4]

The psi gauge is located within one foot inside the one inch diameter galvanized inlet from the community well. That gauge drops to about 15psi when the downstairs water fixtures are flowing and to about 5psi when the upstairs water fixtures are flowing. As noted above, I have read from other sources that a galvanized replacement re-pipe or well house supply line restriction or leak could cause the flow restriction. Would a 86 gallon tank pressurized at 28 psi with no booster pump increase pressure and or water flow to the upstairs water fixtures?

This is pretty astounding. What we would infer from what you observed includes

• a severe restriction between the well house and the house pressure gauge. This could be due to gunked up or rusted up piping, or some other restriction.
• for some strange reason, the upstairs fixtures draw a lot more (almost 3x) gpm despite being supplied with less pressure. That is the weirdest of the two

Is there a valve, a filter, or any other device visible in the path before the pressure gauge?

Regarding the pressure tank, yes it would help work around the problem to an extent. But new polyethylene supply line from the well house would help more.

More testing seems in order. Does your pressure get affected when the other house on the shared well is drawing water?

 

[Bannerman]

A well pressure tank is actually two seperate chambers separated by a flexible synthetic rubber diagphram. In one chamber, compressed air is added which will deflect the diagphram toward the water chamber.

When incoming water pressure exceeds the air chamber pressure such as when the well pump is running, water will enter the water chamber and will push on the diagphram, further compressing the air until the pressure in both chambers is equalized. When water is utilized while the pump is not running, that will cause a pressure reduction in the water system so the compressed air will act as a spring to push the stored water out from the tank so as to maintain equal pressure between both chambers in the tank.

The highest pressure the tank can store is determined by the incoming water pressure. The highest pressure you mentioned was 66 psi so the tank will store 66 psi, but that pressure will be reduced whenever the incoming supply pressure is lower for whatever reason. If water use by your neighbours is causing a pressure reduction, then water from your pressure tank will flow back out to their homes. To prevent that, a check valve (one way valve) would be needed before the pressure tank to ensure the water exiting your tank will flow only to your fixtures.

Most well systems are designed for 20 psi differential between the pump start pressure and the pump stop pressure such as 30/50 or 40/60. The stated fluid capacity for each tank is typically based on 20 psi differential so an 86 gallon tank fluid capacity will be roughly 1/4 of the tank volume or ~ 22 gallons over that 20 psi range. Decreasing the air precharge pressure to allow greater pressure range will allow additional fluid capacity, but the flexible diagphram will undergo additional flexing and stretch forces which may reduce its lifespan.

Once the pressure of the stored water is reduced equal to the incoming pressure, further water use will be again 100% reliant on the incoming flow rate from the shared well system.

IMO, installing a pressure tank is not a suitable remidy as you are only addressing a symptom, not the cause of the problem. If the flow rate reduction to your home is caused by corrosion within the galvanized supply pipe, then it seems likely, further corrosion will cause further flow reduction which is likely to eventually result in no flow whatsoever.

A 1" supply line and 66 psi is more than sufficient to supply an average home. The correct remidy will be to identify the reason for the reduced flow so as to address the cause.

 

[JOHN H SULLIVAN]

Thanks to everybody who took the time to reply and explain. I do have a one inch diameter check valve installed at the inlet of the well pipe to the house; the check valve is located directly after the new 1" gate valve. The pressure tank will be about one foot further inside the house. About two years ago, I installed a harbor freight combo booster pump/pressure tank at that location, which worked about 18 months before it rusted out (and the loud booster pump noise bothered my mom). Based on your and other comments, I believe that the heavy iron in the community well supply line has either rusted up the inside of the supply line or caused a non-observable leak. It is also likely that the house's interior pipes are also restricted by rust build-up. As we are selling the house, we don't want to dig up the yard yet for the sixty feet to the community well pump house. First, we will see if a 86 pressure tank allows a reasonable upstairs shower and upstairs toilet tank fill time. If that fails, we will re-pipe pex to the upstairs bathroom. If that fails, somebody digs up the yard.

 

[wwhitney]

The psi gauge is located within one foot inside the one inch diameter galvanized inlet from the community well. That gauge drops to about 15psi when the downstairs water fixtures are flowing and to about 5psi when the upstairs water fixtures are flowing.

To be clear, those drops (from the 66 psi static pressure you mentioned) are extreme. They imply two things:

1) Your upstairs fixtures are calling for more water than your downstairs fixtures.
2) The blockage is upstream of the gauge.

So any changes you make downstream of your gauge aren't going to improve the situation. The pressure tank may mask the situation for short duration flows.

Cheers, Wayne