Supermarket chiller leak: condensate, water supply or refrigerant?
Water pooling at a chiller or freezer can be defrost water, a supply leak or a sign of a refrigerant fault. How to tell which it is, and who to call for each one.
It is a familiar sight on a store walk: a pool of water in front of a multideck chiller, or a wet strip along the base of a freezer island, and a colleague with a mop who has already dealt with it twice this week. The water keeps coming back, and nobody is quite sure whether it is the cabinet, the pipework or something worse.
There are three likely sources, and each one needs a different person. Getting it right first time saves a wasted call-out and, where refrigerant is involved, keeps you on the right side of the law.
The three usual suspects
Condensate and defrost water. Refrigerated cabinets pull moisture out of the air as they cool, and they melt ice off the evaporator coil during defrost. That water collects in a tray and is carried away through a condensate drain, usually to a floor gully or into the drainage system. Water on the shop floor means that route has blocked, cracked, come loose or backed up.
A water supply leak. Some chilled areas have mains water close by: produce misting systems, ice machines, hand wash basins at a deli or fish counter, cleaners’ sinks. A leaking supply pipe or fitting keeps going whatever the cabinet is doing, and it shows on the water meter.
A refrigerant fault. Refrigerant escapes as a gas, so it rarely leaves a puddle of its own. What it can do is stop the cabinet cooling properly, which often shows as heavy icing, extra defrost water and temperature alarms. An oily residue at a pipe joint is often a sign too, because oil in the system can travel with the escaping gas.
How to tell them apart
Start with timing and the water itself. A few minutes of watching will usually narrow it down.
| What you notice | Most likely source | Who to call |
|---|---|---|
| Water appears after defrost, clean and cold | Blocked or damaged condensate drain | Refrigeration contractor or maintenance team to clear the line |
| Water pooling near a floor gully, slow drainage, a smell | The drain the condensate runs into | Drain leak detection or drainage contractor |
| Water keeps coming regardless of defrost, meter moves with water off | Leak on a mains supply pipe or fitting | Leak detection engineer or WaterSafe plumber |
| Cabinet warm, heavy ice, oily marks at joints, alarms | Refrigerant fault | Qualified refrigeration contractor |
| Water rising from the floor near the cabinet | Buried supply pipe, or a condensate or drain line under the slab | Leak detection engineer |
Three checks help:
- Watch the defrost. Most cabinets have a controller showing when defrost runs. If the water appears around those times and stops between them, condensate is the prime suspect.
- Read the water meter. Turn off the water-using outlets and appliances you safely can, read the meter, wait ten minutes and read it again. Condensate never passes through your meter, so a moving dial points to a supply leak. Leave the refrigeration itself running.
- Look at the cabinet. Is the product at temperature? Is there ice where there is not normally ice? Is the condensate tray full or overflowing?
Refrigerant leaks: the rules you need to know
If the signs point to refrigerant, stop there and call your refrigeration contractor. GOV.UK guidance says you must have your own qualifications to work on equipment containing F gas, even if you work for someone else, and that it is against the law to work with F gas without the correct qualifications. REFCOM, one of the F-gas certification schemes, keeps a register of certified companies and engineers, which is a quick way to check a contractor.
The operator of the equipment has duties as well. GOV.UK’s guidance on checking F gas equipment for leaks says equipment containing F gas equivalent to 5 tonnes of carbon dioxide or more must be leak checked: at least every 12 months from 5 up to 50 tonnes, and at least every 6 months from 50 up to 500 tonnes. Equipment at 500 tonnes or more must be leak checked at least every 3 months and must also have an automatic leak detection system that alerts you, or the service company responsible, when it detects a leak. Where automatic leak detection is fitted, the time allowed between checks doubles. Check the current GOV.UK guidance for your system. If a leak is found, it must be repaired as soon as possible and the test repeated within a month to check the repair worked.
In most supermarket chains, the refrigeration contractor or head office engineering team holds those records. If you manage a single store, ask them which of your systems fall into which band.
Water leaks: the rules for the pipework
Water supply pipes and fittings in shops fall under the Water Supply (Water Fittings) Regulations 1999 in England and Wales, with equivalent byelaws in Scotland. Schedule 2 of the regulations says no water fitting shall be embedded in any wall or solid floor, and that fittings with joints must not be concealed. Older stores sometimes have pipes to counters and wash basins running under the floor anyway, which is why a supply leak near a chiller can surface some distance from the break.
That is the side of the problem we handle. ADI finds leaks on water mains and supply pipes, drains and washrooms, including pipes that run beneath the shop floor. Refrigerant circuits stay with your refrigeration contractor.
Keep the floor and the people safe
Whatever the source, a wet floor in a chilled aisle is a slip risk, and cold air makes floors slower to dry. HSE’s slips and trips guidance sets out the causes and how to prevent them. Put signs out, keep the area dry, and move promotional stands that stop cleaners reaching the wet patch.
Take care around electrics. Cabinets, lighting and plug-in units sit close to the floor, and water spreading beneath them is a hazard. Do not let staff move or unplug wet equipment. Ask a competent person to isolate the power if water has reached electrical parts.
When to call a leak detection engineer
Call us if the meter moves with the water off, if water is coming up through the floor, or if a drain near the cabinets keeps backing up. A survey uses acoustic listening, thermal imaging and tracer gas to find the break, so any opening in the floor is usually small and in the right place, and our insurance-ready reports can go straight to your insurer. We aim to find and repair on the same day where we can. Read more on how it works.
ADI has worked on leaks for over a decade, with 25 engineers across England, Scotland and Wales. We are accredited by CIPHE, WIAPS, WaterSafe and SPATA, and carry £5m public liability cover.
To book, call 0333 567 2615.
Frequently asked
Is a puddle under a multideck chiller always a fault?
It usually means something has gone wrong with drainage or supply. Refrigerated cabinets produce condensate and defrost water as part of normal running, and that water should drain away unseen. Water on the floor means the drainage route has failed somewhere, or the water is coming from another source.
Can a leak detection engineer fix a refrigerant leak?
Refrigerant is a job for a qualified refrigeration contractor, F gas certified where the system uses F gas. GOV.UK guidance says you must have your own qualifications to work on equipment containing F gas, and that it is against the law to work with F gas without them. A leak detection engineer deals with the water side: supply pipes, drains and washrooms.
What should staff do straight away?
Make the floor safe, keep people away from any wet electrics, and note the time the water appears. That timing is often the quickest way to tell defrost water from a supply leak.