Low Water Pressure in Wellington
A trickling shower is the most common complaint in Wellington homes built before the 1990s. Most are running an old low-pressure hot water system — maximum pressure around 7.6m of head (76 kPa) — paired with narrow-bore galvanised pipes that have corroded from the inside.
The fix depends on the cause. Southern has been solving this for 40+ years across Karori, Khandallah, Johnsonville and the Hutt Valley. Call 0800 484 353 and we’ll diagnose it before we quote.
Low, High or Mains Pressure — What’s the Difference?
Low pressure systems are fed by a header tank in the ceiling. Gravity pressure caps at ~76 kPa — enough for a shower but not a powerful one. You can spot them: a small tank in the ceiling cavity, slow-filling cisterns, and a cylinder without a pressure-reducing valve.
High / mains pressure feeds directly from the incoming water supply — usually 500 kPa after the pressure-limiting valve (network can reach 1000 kPa). You get punchier showers, faster cistern filling, and the freedom to use modern tapware designed for mains pressure.
A high-pressure mixer won’t work well on a low-pressure system — the small ports restrict flow and you’ll get even less shower. Matching the mixer to the system is step one.
Seven Ways to Improve Low Shower Pressure
Rough budget ranges — we always quote fixed-price after a diagnostic visit:
- Change the shower rose — $350–$650. Sometimes the rose is the restriction, not the pipework.
- Change the shower mixer — $800–$1,900. Matches the mixer to your system pressure.
- Upgrade cold supply to mains + mixer change — $800–$1,900.
- Install a booster pump — $1,400–$2,600. Good if the rest of the system is sound.
- Pressure-reducing valve system — $2,800–$3,800.
- Replace with a valve-vented system — $3,485–$3,900.
- Upgrade to a high-pressure hot water cylinder — $4,200–$5,600. See our hot water cylinder page.
When the Answer is a Full System Swap
If the hot water cylinder is ageing or the house needs a full re-pipe anyway, going straight to a modern mains-pressure system is usually cheaper than patching around the old one.
- Gas continuous-flow system — $4,500–$6,000. Endless hot water, mains pressure.
- Heat pump water heater — $9,000–$12,000. Highest efficiency, lowest running cost over 10+ years.
We also replace narrow-bore pipework with larger-bore copper or Pex where the pipes themselves are the bottleneck — particularly in homes still running original Dux QEST or galvanised lines.
Diagnose Before You Buy
We’ve seen people spend $2,000 on a booster pump that didn’t help — because the restriction was in the shower rose. Or they’ve replaced the mixer and gotten worse flow — because they put a mains-pressure unit on a low-pressure system.
Our pressure diagnostic is a small service call: we measure at the meter, at the cylinder, at the shower arm. We tell you where the restriction is, then quote the fix. If you proceed, the diagnostic is credited to the repair. Serving Karori, Johnsonville, Khandallah and the Hutt Valley with real data, not guesses.
Related Pressure Problems
Low pressure often travels with other symptoms. If you’re noticing any of these, call us — it points to a system-level problem, not just a shower issue:
- Hot water running out quicker than it used to
- Kitchen tap flow dropping at the same time as the shower
- Discoloured or rust-tinted water from the hot side
- Unexplained water bills — could be a hidden leak dropping supply pressure
- Banging pipes or water-hammer when taps close
- Toilet cisterns taking 5+ minutes to refill
Call 0800 484 353 — 24/7, every public holiday.
Frequently Asked Questions
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Most commonly you’re on a low-pressure (header-tank) system — max 76 kPa — paired with a restrictive shower rose, an undersized mixer, or corroded galvanised pipework. Occasionally it’s a partially closed valve or a hidden leak. Diagnosis is usually a 30-minute service call.
