Chimney Oil Dripping or Leaking? Causes and Fixes
Oil dripping from a kitchen chimney onto the hob usually comes from one of four places: a full or badly seated oil collector, saturated filters, an oil channel choked with hardened grease, or grease built up inside the hood. Empty the oil cup and wash the filters first. If it still drips, the cause is further in, and it needs a deep cleaning or a repair check. It is usually a cleaning job rather than a faulty part.
Where the oil is meant to go
Indian cooking sends a lot of fine oil up into a chimney. Where it ends up depends on the type of chimney:
- Baffle or mesh filter chimneys. The filters catch most of the oil, and it sits in the filter plates and the channel behind them until they are cleaned.
- Filterless chimneys. There are no filter plates. Oil runs down the inner cone into an oil collector, a cup or tray that has to be emptied.
- Auto-clean chimneys. A heating element loosens hardened oil and drains it into the collector. Auto-clean moves oil; it does not clean the filters, the duct or the outside of the hood, and the cup still needs emptying.
A chimney drips when the oil cannot reach the place it is meant to collect, or when that place is already full.
Checks you can do yourself
Do these with the hob off and the chimney cool. None of them involve opening the chimney.
| Check | What you see | Points to |
|---|---|---|
| 1. Look at the oil cup or tray | Full, or close to it | Empty and wash it, and from now on empty it when it is half full |
| 2. Take the cup out and refit it | It does not sit flush, or the lip looks warped | A collector that no longer seats properly, a common cause of a leaking hood |
| 3. Look at the filters | Dark, sticky, or with oil pooling in them | Saturated filters. Wash them |
| 4. Watch where it drips after that | Still dripping, but the cup is nearly empty | The oil is not reaching the collector, usually because the oil channel is choked. Needs a deep cleaning or a repair check |
These checks point you in a direction; they are not a diagnosis. Do not open the motor housing or control panel yourself.
The usual causes
| Cause | What happens | What fixes it |
|---|---|---|
| Oil collector full | The cup or tray overflows onto the hob | Empty and wash it; empty it when it is half full |
| Collector not seated | Common after it has been removed and refitted a few times, or once heat has warped the lip | Reseat or replace the collector, and renew a hardened gasket |
| Oil channel choked | Hardened grease blocks the channel that feeds the collector, so oil backs up and finds another way out. On baffle models the channel behind the filter plates clogs the same way | Flush the channel, which is part of a deep cleaning |
| Saturated filters | The filters hold more oil than they can | Wash or replace the filters |
| Grease built up inside the hood | Oil coats the inner cone, fan and motor housing | A deep cleaning, where the chimney is opened |
| Condensation from the duct | Condensation runs back from the duct into the hood | Check the duct slope and the outside opening |
Why emptying the cup is not enough
Emptying the collector clears what has already drained; it does nothing for what is stuck on the way there. On a filterless chimney the inner cone, the impeller and the motor housing still coat up with oil, and they can only be reached by opening the chimney. On a baffle chimney, washing the filters at home does not reach the channel behind the plates, the impeller or the duct mouth. That is what a deep cleaning is for.
Oil leakage is worth dealing with early. Left alone, oil creeps past the collector into the body of the chimney and down the wall, and what began as a cleaning job can turn into panel and cabinet damage.
What the technician does
- Finds where the oil goes. The technician opens the hood, traces the oil channel and shows you the fault before quoting. Floors and the hob are covered, and oil-soaked parts are degreased in a tray.
- Deep cleaning. The chimney is opened, where the design allows, to clean the fan, blower and inner hood. The oil channel, the collector and the duct mouth are cleaned along with the filters.
- Collector and channel work. The channel is cleared, the collector reseated or replaced, and a hardened gasket renewed.
Before anyone travels, you get a probable cause, a price range and the visit charge, which covers travel to your home. If you go ahead with the work, the visit charge is adjusted into the bill. See how our charges work.
How to stop it happening again
- Empty the oil cup when it is half full, and wash it while the filters dry.
- Wash baffle or mesh filters every two to three weeks if you cook daily.
- Run the chimney a few minutes before and after cooking, and use a higher speed for frying.
- On auto-clean models, run the cycle as the manual says and empty the cup.
- Book a professional cleaning if it has been more than six months with daily cooking.
See how often to clean a kitchen chimney for a full schedule.
Questions about oil dripping from a chimney
Why is oil dripping from my chimney onto the hob?
Usually a full oil collector cup, saturated filters, a collector that no longer seats, an oil channel choked with hardened grease, or grease built up inside the hood. Empty the cup and wash the filters first. If it still drips, it needs a deep cleaning or a repair check.
The oil cup is nearly empty but the chimney still drips. Why?
A nearly empty collector on a chimney that is dripping means the oil never reached it. The oil channel is usually choked with hardened grease, so oil backs up and finds another way out. It is a cleaning job rather than a part failure.
Does auto-clean stop oil dripping?
Auto-clean loosens oil and drains it into the collector, so it keeps oil moving, but it does not clean the filters, the duct or the outside of the hood, and the cup still needs emptying. Auto-clean faults include a failed heating element and oil bypassing the collector, which is a repair check.
Is oil dripping a cleaning job or a repair?
Usually a cleaning job: a full cup, saturated filters or a choked oil channel. A collector that no longer seats can be reseated or replaced, and a hardened gasket renewed.
Can a dripping chimney damage the kitchen?
It can if it is left alone. Oil creeps past the collector into the body of the chimney and down the wall, and a cleaning job can turn into panel and cabinet damage, so it is worth dealing with early.