Quick Answer:
If tap water feels slick or greasy after bringing your plumbing back into service, it’s usually leftover antifreeze or oil-type residue from winterization. Stop drinking the water, then flush every fixture and appliance thoroughly. If the oily feel remains after careful flushing and filter changes, call a plumber or water-treatment pro.
Why This Happens
- Many winterization processes use non-toxic propylene glycol or other antifreeze that can leave a film in pipes, fixtures and appliances if not fully flushed.
- Residue collects in low spots, aerators, faucet cartridges, appliance lines and traps. When water flow is low, that residue can mix with water and feel slick.
- In older homes, oils or deposits from pipes and tanks can also be dislodged during winterization or by stagnant water sitting in lines.
Step-by-Step What to Do
1. Stop using the water for drinking and cooking
Until you’re confident the residue is gone, use bottled or boiled water for drinking and food prep. Avoid giving household water to pets.
2. Flush all fixtures after winterization
Open every cold and hot tap in the house, one at a time, and run until the water feels normal. This includes sinks, tubs, showers and outdoor faucets. Let each fixture run several minutes; for stubborn residue, run 10–15 minutes per fixture.
3. Flush appliances and supply lines
- Run the dishwasher and washing machine through an empty cycle with hot water to clear their supply lines.
- Run the ice maker water line and any in-line filters by dispensing several gallons until the stream is clear.
- Check and flush the water heater by running hot water from a sink for several minutes and consider draining a small gallon to remove settled residue.
4. Check and clean fittings and aerators
Remove faucet aerators, showerheads and strainers. Rinse or soak them and run the tap to clear trapped film. Replace cartridges or seals if they look contaminated.
5. Replace or clean filters
Change point-of-use filters (refrigerator, under-sink) and whole-house sediment/carbon filters if you used them before winterization or if they were exposed to antifreeze. A fresh filter helps remove lingering taste, odor and film.
6. Inspect appliances for visible film
Look inside washing machine tubs, dishwasher interiors and toilet bowls. Treat visible oily buildup with a manufacturer-recommended cleaning cycle or manual cleaning. You may find an oily residue in the machine; see Oily film in washing machine and Oily sheen in toilet bowl for related cleaning notes.
7. Test and monitor
- After flushing and cleaning, test the water by checking feel, smell and taste. If anything is off, continue flushing and replacing filters.
- If you suspect antifreeze contamination, stop using the water and contact a professional for testing. Don’t rely on feel alone for safety.
What Not to Do
- Do not re-winterize without flushing residue.
- Do not run strong chemicals down drains or into the water heater to “neutralize” antifreeze unless advised by a professional—this can harm fixtures and disposal systems.
- Do not assume the water is safe to drink based only on appearance. If in doubt, get a professional test.
When to Call a Professional
- If the greasy feel persists after thorough flushing and filter replacement.
- If you detect a foul chemical smell, are unsure which type of antifreeze was used, or household members show signs of illness.
- If buildup appears inside appliances or the water heater and you’re not comfortable performing a full service flush or drain.
Safety Notes
- Treat any unknown chemical contamination seriously. Some antifreezes are toxic; if you suspect ethylene glycol was used, avoid all contact with the water and call a professional immediately.
- Collect flushed water in buckets if local disposal rules require special handling—check local guidance for antifreeze disposal.
- When cleaning aerators or fixtures, wear gloves and protect surfaces. Rinse thoroughly afterward.
Common Homeowner Questions
- How long should I run each tap?
Run until the water feels normal; typically 5–15 minutes per fixture depending on severity. - Will changing filters solve it?
Filters help but should be combined with full flushing; change filters after the initial flush to avoid trapping residue in the new filter. - Is the water safe to drink after flushing?
Only if the greasy feel, smell and taste are gone; if there’s any doubt, get the water tested before drinking.
Related Articles
If you’re troubleshooting a similar symptom, these guides may help:
For the full directory, see Oily Sheen, Slick Feel, or Soapy-Like Water.