Our case is slightly different from Todd's.

The piping was bored down to the first available porous layer (they basically kept going until the mud and sand they were squirting all over the yard turned into water).

The two options for a pump were then either a surface pump or a submerged pump. The latter is better, since it doesn't require any force to raise the water before the supply side - however we opted to use our previous surface pump to save money. Despite a 35 meter rise before the supply side we still get good pressure.

The pump itself generates the pressure for the domestic system. In our previous well we had a smaller borehole and thus on the supply side of the system we had a small pressure tank which evened out the pressure delay between a tap being opened and the pump bringing the system up to the correct pressure. In our new system, the borehole and pump can supply full pressure almost instantly so our installer suggested we didn't need a pressure tank.

Our water heater is a solar deposit system which uses a heat exchanger to step down the stored, heated water from 80C to domestic temperatures. A water heater doesn't provide pressure; that comes from the water pressure maintained by the pump or domestic supply.

The solar system is backed up by a propane deposit which cuts in automatically if solar supplies are insufficient over a few days. The entire system supplies domestic hot water and central heating. Mostly 7 months a year it is 100% solar energy. The rest of the year, depending on conditions, it can be 30-40% solar with the propane supplying the shortfall.

As I mentioned in the previous post we're still on grid for our electrical needs. If we have a long term power cut, the only solution at the moment is to plug in a generator which can supply all the essentials (water, solar system, some lighting) but we plan to invest in photovoltaic systems specifically sized to run the pump, the solar system and with enough reserve for some lighting and small electrical items which would mean that if the power went out .. forever ... we'd still be ticking over.

"In our new system, the borehole and pump can supply full pressure almost instantly so our installer suggested we didn't need a pressure tank."

From everyone I've talked to in the well industry this was bad advice.

The reason you have a pressure tank is to keep your well pump from running on/off each time you run the water in the house. This is what kills the pumps going on/off repeatedly and why they suggest to size your pressure tank accordingly (don't get to small of a one or it will still do it). With a pressure tank the well then might run once a day or two times a day depending on the size and number of people in the house.

I`m pretty sure this holds true for all electronic devices, especially motors... running for long periods of time is normally fine but going on and off throughout the day can kill them much quicker.

Maybe you guys have a special pump? I'd call around and investigate this though to be 10000000% sure because you don't want that baby to die on ya when you need it most

Also, you guys could add a hand pump since your well under 200ft

Let me know what they say if you call around.

+1 on that.
One of my jobs involves working in state parks. Where I work, we have seven different systems, all with pressure tanks. When these systems are overtaxed, as on a holiday weekend, the pressure tanks become "waterlogged" (the frequent flow of the water from the pump into the pressure tank stirs bubbles from the air reservoir into the water, which get sucked further down the line, and flushed out the toilets. This limits the amount of pressure available, and causes the pumps to cycle on and off more often. When this happens, and no one realizes it, the pumps burn out from the constant cycling on and off.
The "funny" thing about this is: these systems were put into place thirtysome years ago, have never been modified with a larger pressure tank, and I've been draining the freaking things everytime they get waterlogged. And yeah, I suggested larger pressure tanks. Apparently it's cheaper if I remember to go drain off some water every holiday weekend...
I shouldn't complain: it's better than trying to reset a burned out pump in a septic pumping station. There's an ugly job.

[Okay, guys, I'm supposed to be "all in" on a work project that will feed me for the rest of this year, and maybe two more, but I can't resist commenting. :-]

UncleGoo, you're talkin' my language.

As you know, pressure tanks rely on a "spring" of air at the top. (Basic physics: liquids don't compress hardly at all; but gases compress readily.) Most older pressure tanks , including my current one and all the ones I grew up with, lose their air cushion over time. Turbulence dissolves (incorrect term) the air and pushes it out the pipe.

Solution: once a year, turn off the pump, drain the tank of all pressure (open the taps), close all taps, and use a compressor to pump in approx. 30 psi. Then turn on the pump, and open an outside tap (say on a tree) while all that crud you've stirred up on the bottom of the pressure tank blows out.

Now you have a smooth running system. The pressure holds a long time and drops off gradually. The pump runs only occasionally, for a longer period, extending its life greatly; frequent stops and starts kill motors quick. Also, you will pay less per gallon/litre; frequent motor starts draw rather a lot more electricity.

New pressure tanks have a bladder at the top, which mostly solves the loss-of-air-cushion issue.

I have a shallow well with a new foot valve, which means a small hand pump can be tapped in very easily. (There it is on the shelf, with fittings, ready to go. Imagine that ;-) The downside is that, in this drought year, the amount of dissolved salt/mineral in the water has increased noticeably. I'm looking at a reverse osmosis system to mitigate potential adverse health effects.

[Okay, that's enough fun. Keep on truckin', guys. It's back to the salt mines for me. Dougwa_ out.}

Thanks for the much more articulate explanation--have you been looking over my shoulder?

The pressure tank we installed has the bladder, and the one I removed did too.. however it was OLD, popped, and the P/O were still using it! They were just pressurizing the entire tank, and wow it had rusted, and was NASTY! It's a nice BBQ now

Adding a schrader valve somewhere on the tank helps to add air without having to completely drain the tank. Especially when you are in a hurry.

And if you want to do it right dougwalkabout's way is the way to go. But remember to only charge the pressure tank with air to slightly less than the pumps cut in pressure. My well has a 20-40 pressure switch on it and pressurizing with air to 30psi means that the pump won't come on till some of the air bleeds out. I hope that made sense.

Hi Todd

Thanks for the heads up. I'll have a word with the installer and find out more about his reasoning. The house here is quite tall and I did discuss the possibility of putting in a gravity feed tank but apparently these are against building code here now (I'm in Spain) due to bacterial growth.

It may have been a cost issue; I'll look into it though.