FAQ
TL;DR: Correctly precharged, a 300 L steel hydrophore should deliver 60-140 L per cycle [Elektroda, sigwa18, post #14105571] “Leave 2 cm of water and pump to 2.2 bar” [Elektroda, Wawrzyniec, post #15487192]
Why it matters: Proper air balance cuts pump starts by up to 65 % and extends motor life.
Quick Facts
• Cut-in / cut-out settings used in thread: 2.2 bar on, 4.2 bar off [Elektroda, woda_cisowianka007, post #14105449]
• Recommended pre-charge: 0.1–0.2 bar below cut-in (≈2.0–2.1 bar here) [Grundfos, 2023]
• Expected draw-off at correct charge: 100–140 L per cycle for a 300 L vessel [Elektroda, sigwa18, post #14105571]
• Air-top-up interval: 3–12 months, depending on leaks and water solubility [Pentair, 2022]
• Diaphragm tanks reduce air loss by ≈90 % versus plain steel [Watts, 2021]
How much water should a 300 L hydrophore supply per cycle?
With the air cushion set correctly, users report 100–140 L before the pump restarts [Elektroda, sigwa18, post #14105571] A smaller 60 L draw means the tank holds too much water or not enough air [Elektroda, woda_cisowianka007, post #14113362]
What air pressure should I set?
Aim for 0.1–0.2 bar below the pump’s cut-in. For a 2.2 bar start, pre-charge at 2.0–2.1 bar [Grundfos, 2023]. Forum testers used 2.2 bar with good results [Elektroda, Wawrzyniec, post #15487192]
Do I need to drain all the water before pumping air?
No. Leave 2–3 cm visible on the gauge, then add air. This prevents air escaping into the piping [Elektroda, Wawrzyniec, post #15487192]
Three-step method to recharge a plain steel tank?
- Switch off pump and open a tap until water sits 2 cm on gauge. 2. Pump air to 2.1 bar. 3. Close taps and power the pump; verify cut-out at 4.2 bar [Elektroda, sigwa18, post #15487374]
Why does water squirt from the Schrader valve?
Water at the valve means the air cushion is gone or the diaphragm is ruptured. Replace the valve core first; if water still appears, the bladder has failed and needs replacement [Elektroda, Wawrzyniec, post #16831827]
What if the pump will not start after adding air?
You over-pressurised. Bleed air until vessel pressure falls 0.1 bar below the switch cut-in, then retry [Elektroda, Wawrzyniec, post #14106910]
Can I inflate through a basement valve past the check valve?
No. The check valve blocks air. Use a port above the water line, such as the upper gauge outlet, to avoid backflow to the well [Elektroda, woda_cisowianka007, post #14107917]
How often should I top up the air?
Check quarterly; recharge when draw-off volume drops 20 %. Air loss can reach 10 % per month in steel tanks [Pentair, 2022].
Edge case: I cannot pump any air in; what now?
A stuck or rusted Schrader valve prevents flow. Replace the core; if pressure still reads zero, the gauge or valve seat is blocked [Elektroda, kajattar, post #16829778]
What happens if there is too much air?
Excess air causes water hammer and may push air into the piping, leading to sputtering taps. Keep pre-charge within the 0.2 bar window [Grundfos, 2023].
Will a diaphragm (bladder) tank solve frequent air losses?
Yes. Bladder designs isolate water and air, cutting diffusion losses by roughly 90 % and reducing maintenance [Watts, 2021].
Why does pressure drop 0.8 bar after pump stops?
A leaking foot or check valve lets water run back to the well. Replace the valve to maintain the static 4.2 bar [Elektroda, woda_cisowianka007, post #14118754]
