Quick Answer:
If water turned cloudy right after a pressure-reducing valve (PRV) was installed, the most common cause is air introduced into the plumbing or a pressure change that releases dissolved gases. In many cases the cloudiness clears after running the tap for a few minutes. Try simple checks and adjust the regulator slowly while watching the water; if the problem continues or you see particles, get professional help.
Why This Happens
Installing a PRV changes line pressure and can introduce air pockets into pipes. Tiny air bubbles make water look white or cloudy; they usually rise and clear from the bottom of a glass upward within a minute or two. Other possibilities include:
- Disturbed sediment or scale that was loosened during work on the line.
- Precipitation of minerals when pressure or temperature changes quickly.
- Issues limited to hot water systems (tank sediments or degradation) or to a single fixture.
If cloudiness only affects one fixture, see Milky water in shower only. If you notice flakes or solid bits, that may be different from simple aeration — see White particles in hot water.
Step-by-Step What to Do
Step 1 — Compare hot and cold
- Turn on a cold tap and a hot tap side by side. If only cold is cloudy, the issue is likely air or pressure in the supply line. If only hot is cloudy, it could be the water heater.
Step 2 — Run and observe
- Open a couple of taps fully and let them run for 3–5 minutes. Watch whether the cloudiness clears from the bottom of a glass upward — that indicates air. Note whether it clears faster at different pressures.
Step 3 — Adjust PRV slowly and observe changes in cloudiness
- Make only small adjustments to the PRV setting, then wait a minute and check the water. Adjusting too fast can trap more air or cause pressure swings. If lowering or raising the setpoint reduces the cloudiness, let it stabilize at that setting.
Step 4 — Check fixtures and aerators
- Remove and inspect aerators and showerheads for trapped debris. Rinse them and test the flow again.
Step 5 — Isolate and test
- If the problem persists, isolate sections by testing multiple fixtures around the house. If all fixtures show the same cloudiness, the supply or PRV is the likely cause. If only one branch is affected, the issue is local to that line or fixture.
What Not to Do
- Do not adjust regulators blindly. Sudden or large changes can cause pressure problems, leaks, or more aeration.
- Do not dismantle the PRV or plumbing if you are not experienced; improper reassembly can create leaks or unsafe pressure conditions.
- Do not assume cloudy water is safe if you see colored water, strong odors, or visible particles; those signs need testing or a pro inspection.
When to Call a Professional
- If cloudiness does not clear after running taps and carefully adjusting the PRV for a few hours or a day.
- If you find visible particles, discoloration, or a rotten-egg smell — those can indicate corrosion, contamination, or heater issues.
- If adjusting the PRV causes unstable pressure, hammering, leaks, or if you are unsure how to set the valve safely.
Safety Notes
- Air in the water is not harmful, but persistent cloudiness with particles or odor may mean contamination — avoid drinking until you have clarity or a test result.
- Work on household pressure devices can create high-pressure conditions; if you are not comfortable, call a licensed plumber.
- If you suspect contamination from municipal work or a main break, contact your water utility for guidance and testing.
Common Homeowner Questions
- Is cloudy water dangerous? Usually not when caused by air; it clears quickly. If there are particles, color, or odor, treat it as potentially unsafe and get it checked.
- How long should the cloudiness last? Air-related cloudiness usually clears within a few minutes of running the tap; if it persists beyond a day, investigate further.
- Can I fix the PRV myself? Small adjustments to the PRV can be done carefully, but if you are unsure, or if pressure is unstable, hire a plumber to set it properly.
For more related articles, see the White Particles, Cloudy Water, or “Milky” Water hub.