Interceptor cleaning keeps grease, oil and silt where they belong: trapped in the interceptor rather than travelling down the drain. When an interceptor is left too long, it stops separating and passes waste straight through, and the blockage shows up further down the line. We look after the drainage around interceptors for restaurants, takeaways, garages and yards. Call 07427 195142 to arrange a visit.
What an interceptor does
An interceptor is a chamber, or a series of chambers, that slows waste water down so that whatever it is carrying can separate out. In a kitchen, a grease interceptor lets fat cool and float to the top while the cleaner water flows on underneath. On a forecourt, car park or workshop yard, an oil interceptor holds back fuel and oil, and the heavier silt drops to the bottom. Each one has a limit. Once the layer of fat, oil or silt gets too deep, there is no room left for separation to happen.
Signs an interceptor needs attention
Most of the warnings appear in the drains around the unit rather than in the interceptor itself.
- Kitchen sinks and floor gullies draining slowly
- Grease smells around the kitchen or yard
- Fat or oil visible in the next manhole downstream
- Water backing up into the interceptor during busy service
- Repeat blockages in the line leaving the building
What the cleaning visit covers
We lift the covers, check the level and condition of each chamber, and clear the pipework on both sides. The inlet from the kitchen or yard usually carries a build-up of fat or silt of its own, and the outlet can be coated where the interceptor has been overloaded. High pressure water jetting scours those lines back to the pipe wall instead of just opening a channel through them.
Where something looks wrong, such as a damaged baffle, a cracked chamber or a pipe that has dropped, a camera inspection shows the detail. A CCTV drain survey with footage and a written report is also useful if a landlord, insurer or the council asks for evidence of the drain's condition.
Grease interceptors in kitchens
Commercial kitchens send a lot of fat to drain even with careful staff: from pans, fryers, dishwashers and floor washing. A grease interceptor, sometimes called a grease trap, only works if it is sized for the kitchen and emptied before it fills. When it is not, the fat sets hard in the drain beyond it, and hardened fat beyond an overloaded interceptor is a common cause of kitchen drain blockages. Our guide to commercial kitchen grease management covers the day-to-day habits that help.
Planned cleaning and cost
The right interval depends on how busy the premises are, the size of the interceptor and what goes into it. A takeaway frying all day needs more frequent attention than a small café. Booking visits on a schedule usually costs less than one emergency in the middle of service. See our drain cleaning and maintenance service for planned visits.
The cost of interceptor cleaning depends on the type and size of unit, how much build-up there is, the length of drain to be jetted and how easy access is. We price once we know what is on site. If the drains have already blocked, see commercial drain unblocking.
Questions
Is a grease interceptor the same as a grease trap?
The names are used for the same job. Some people say trap for a small unit under a sink and interceptor for a larger chamber outside, but both hold back fat so it does not reach the drain.
How do I know how often to clean it?
Check the depth of the fat or oil layer over a few weeks. Once you know how quickly it builds up, a cleaning interval can be set before it reaches its limit.
Can enzyme dosing replace cleaning?
Dosing products can help break down fat in the lines, but the interceptor still collects solids and grease that have to be removed.
What should staff avoid putting down the sink?
Pouring fat, oil and food scraps straight to drain overloads the interceptor. Scrape plates into the bin and collect used oil separately.