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    What Is a Pressure Reducing Valve and Does Your Home Need One?

    High water pressure quietly wrecks geysers, taps and pipes. What a pressure reducing valve does, the signs your Johannesburg home needs one, and what it costs to fit.

    17 June 2026 6 min read
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    High water pressure feels great in the shower — and quietly destroys your plumbing. In many Johannesburg suburbs, municipal pressure runs higher than household fittings are designed for, and a small valve is all that stands between that and a burst geyser. Here is what you need to know.

    What a pressure reducing valve does

    A pressure reducing valve (PRV) sits on your incoming supply and lowers and stabilises the pressure to a safe level — usually around 400 kPa. It evens out the spikes (often worst late at night) that hammer your geyser, mixers and flexi-hoses.

    Signs your home needs one

    • Pipes that bang or "hammer" when you close a tap
    • Taps that splutter or blast out water
    • A geyser overflow that drips constantly
    • Mixers that drip soon after being serviced
    • Flexi-hoses that burst under the sink or behind the toilet

    Why it protects your geyser

    Excess pressure forces your geyser's safety valves to release again and again — wasting water, stressing the cylinder and cutting years off its life. A correctly set PRV is one of the cheapest ways to extend geyser lifespan and stop that constant overflow drip.

    What it costs

    Supplied and fitted, a PRV typically runs R900–R1,800 depending on access and whether worn valves need replacing at the same time. Against the cost of a burst geyser and a damaged ceiling, it is cheap insurance. It often pairs with sorting out water pressure problems more broadly.

    Not sure what your pressure is?

    We can test your incoming pressure and tell you whether a PRV is worth fitting — no pressure to proceed. Book a check.

    Frequently Asked Questions

    A pressure reducing valve (PRV) lowers and stabilises the incoming water pressure to a safe level — typically around 400 kPa — protecting your geyser, taps, mixers and pipes from the damage high or fluctuating municipal pressure causes.

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