Duct Doctor · London and the South East
Grease trap cleaning and servicing
Under-sink and inline grease traps emptied and cleaned on a schedule, so fats, oils and grease stay out of your drains and the sewer.
- A grease trap that hasn’t been emptied for months
- Slow or blocked kitchen drains
- Bad smells from sinks and drains
What grease trap cleaning involves
Every pot, pan and plate washed in a commercial kitchen sends fats, oils and grease down the drain. A grease trap catches them before they leave the building. Under-sink and inline traps hold the water long enough for the grease to cool, separate and float, so cleaner water can carry on. But a trap only works while it has room. Once it fills, grease passes straight through, drains slow down and block, the kitchen starts to smell, and the fat goes on to help form the blockages in sewers known as fatbergs. We empty the trap, scrape out the grease and solids, clean the inside and check that the baffles and outlet are clear. The waste is removed from site. We can set up a regular schedule so the trap never gets to the point of overflowing. Our article on grease traps explained covers how they work and how to look after them.
We cover London and the South East, and have done since 2009. We’re a BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease, we hold CHAS, SafeContractor and ISO 9001, and we’re fully insured.
Problems we put right
- A grease trap that hasn’t been emptied for months
- Slow or blocked kitchen drains
- Bad smells from sinks and drains
- Grease backing up into the sink
- Worry about causing sewer blockages
What we work on
- Under-sink grease traps
- Inline grease traps
- Pot wash sinks
- Kitchen waste pipes
- Restaurants and takeaways
- School and care home kitchens
How it works
- We find the trap, check its size and type and agree how often it needs emptying.
- The area is protected and the trap is opened up.
- Grease, solids and water are removed and the inside is scraped and cleaned.
- Baffles, inlet and outlet are checked and cleared so the trap works as it should.
- The trap is closed and the area cleaned, and the waste is removed from site.
Why grease traps need regular emptying
A trap has a fixed capacity. Busy kitchens fill it faster, especially if fat is scraped into sinks or poured down drains. Once the grease layer reaches the outlet, it starts passing into the drains. Regular emptying, at a frequency set by how fast your trap fills, keeps it working and avoids an emergency call when the sink backs up.
Helping the trap do its job
Scrape plates and pans into a bin before washing, never pour cooking oil down the sink, and collect used oil for proper disposal. These habits reduce how much grease reaches the trap and how often it needs emptying. They also cut the risk of smells and blockages in between visits. Make sure everyone in the kitchen, including new starters, knows the routine.
Why it’s worth doing now
A full grease trap stops doing its job without any warning sign until the drains slow, the smell starts or the sink backs up mid-service. By then, grease is already in the pipes. Blocked drains can close a kitchen and are an obvious problem at an EHO inspection. Getting the trap emptied and onto a regular schedule now is far easier than dealing with a blockage on a busy night. If you don’t know when it was last emptied, assume it’s due.
What affects the quote
We don’t publish set prices, because no two systems are the same. Send us a few details and photos, or book a survey, and we’ll give you a fixed price before any work starts. The main things that change it are:
- The size of the system: number of canopies, length of ductwork, risers and fans
- How much grease or dirt has built up since the last clean
- Access: roof-level fans, ceiling voids, risers and how many access panels there are
- When the work can happen: overnight, weekends or school holidays
- Whether extras are needed, such as new access panels, filter exchange or damper testing
- How many sites you want covered on one schedule
What a good quote includes
- A survey or clear photos before the price is given
- Exactly which parts of the system will be cleaned or tested
- How areas that can't be reached will be recorded
- A certificate or written report with before-and-after photos
- Proof of insurance and accreditations you can check
- The recommended date for the next visit
Afterwards
The trap is left empty, clean and working, with the area tidied. Keep scraping plates and pans into the bin, collect used cooking oil separately and never pour it down the sink. Tell us if drains start to slow or smell before the next visit. We’ll suggest how often the trap should be emptied, and we can remind you when it’s due.
Grease trap cleaning and servicing: common questions
How often should a grease trap be cleaned?
It depends on the size of the trap and how much grease your kitchen produces. Busy kitchens may need it done often. We’ll suggest a frequency and adjust it once we see how quickly it fills.
What happens if a grease trap isn’t emptied?
Grease passes through into the drains, which slow down and block. Kitchens get smells and backed-up sinks, and the fat can add to sewer blockages.
Do you take the waste away?
Yes. The grease, solids and water we remove are taken off site.
Can you clean the trap when the kitchen is closed?
Yes. We work early, late, overnight or at weekends so the sinks are back in use for service.
My kitchen drain is blocked. Is it the grease trap?
A full or neglected grease trap is a common cause. We can empty and clean it and tell you if the blockage is further down the line.
Do you give a fixed price before you start?
Yes. Send a few details and photos, or book a survey, and we’ll give you a fixed quote, usually within one working day.
Do you work out of hours?
Yes. We work evenings, overnight and at weekends so your kitchen or building doesn’t lose a day, and there’s a 24/7 line for emergencies.
Page updated 30 October 2026
Near you
We cover London and the South East. Find grease trap cleaning in your town:
- London
- Brighton
- Southampton
- Portsmouth
- Reading
- Oxford
- Milton Keynes
- Guildford
- Chelmsford
- Maidstone
- Woking
- Crawley
- Croydon
- St Albans
- Canterbury
- Basingstoke
- Slough
- High Wycombe