Why Your Commercial Fridge Isn’t Cooling (and What to Check Before You Call an Engineer)
Simple checks to try before you call an engineer
We’ve already had a few heatwaves this summer, and plenty of kitchens have been caught out by the same thing. We’ve had so many calls from businesses that found their fridge’s temperatures climbing and their food not cooling properly. Straight away they’re thinking about what an engineer is going to charge them or whether it’s worth getting another fridge instead.
If it’s happened to you, you’re not the only one. A few weeks ago, when it hit 37 degrees, fridges were packing up all over the country. Even the big supermarkets were left with empty shelves because their refrigeration couldn’t keep up.
The thing we explained to our customers is that a warm fridge in this sort of heat often doesn’t mean it’s broken. It’s usually a fridge that’s struggling with the conditions, and that’s something you can often sort yourself without an engineer. So before you pick up the phone, have a go at these checks. A few of them take less than a minute.
First, Why Fridges Struggle in the Heat
A fridge doesn’t actually ‘make cold’, it shifts heat. This means it takes the warmth out of the inside and pushes it out the back (or top, depending on where your fridge’s motor is), through the condenser and compressor.
The hotter your kitchen gets, the harder that becomes, and every fridge has its limit (a bit like us!). When the compressor gets too hot, it deliberately switches itself off. It’s a safety cut-out that stops it burning itself out. So if your fridge has gone quiet and warm on the hottest day of the year, there’s a good chance it’s just protected itself.
Here’s something most people have never heard of. Every fridge has a climate class, which is the top room temperature it’s built to cope with:
- Class 3 copes with rooms up to 25°C.
- Class 4 copes with rooms up to 30°C. That covers most UK kitchens.
- Class 5 copes with hot, busy kitchens up to 40°C.
So if your kitchen crept past 30 degrees in the heatwave and your fridge is a Class 3 or 4, you were asking it to do a job it was never built for. Even though it might seem like it’s faulty, the room actually just got the better of it.
Simple Checks Before You Call an Engineer
Most warm-fridge problems in hot weather come down to one of these, and you can sort them yourself.
1. Check the power and the thermostat
Sounds daft, but it does catch people out. Check the plug is in and the switch is on. Have a look at your fuse board too, in case a breaker has tripped in the heat.
Then check the thermostat dial. It’s easily knocked during a busy shift, or nudged when someone is loading shelves. Make sure it’s still where it should be.
2. Give it room to breathe
This one is so key and one we see many people getting wrong. A fridge that’s jammed against a wall, boxed in, or sat next to the oven or fryer hasn’t got a chance. It can’t get rid of the heat it’s pulling out, so it keeps running and never quite gets cold.
Pull it out a bit, leave some space around it, and move anything hot away from it. There’s more on airflow and where to put things in our maintenance guide.
3. Do the banknote test on the door seal
A worn or grubby door seal lets warm air creep in all day long. In a heatwave, that’s often enough to tip your fridge over the edge.
A quick way to check it is to shut the door on a banknote, half in and half out, then pull. If it slides out with no resistance, the seal isn’t doing its job. Give it a wipe with warm soapy water first, because grease and crumbs often stop the door closing properly. If it’s split or torn, it’ll need replacing.
4. Look for ice building up at the back
If the back wall inside is covered in frost or ice, the defrost system isn’t keeping up. That ice blocks the airflow, so the fridge runs and runs but the cold can’t get round to your food.
As a stopgap, switch it off, empty it, and let all the ice melt before you turn it back on. If the frost is back within a few days, the defrost parts need an engineer to look at them.
5. Try a reset
If the display is showing an error code or playing up, it might just be a glitch rather than a real fault. Turn the fridge off at the wall, leave it ten minutes, then turn it back on. That’ll often clear the code and reset the electronics.
Give it a few hours to get the temperature back down before you decide whether it’s worked. If the same code comes straight back, jot it down. It’ll save the engineer time if you do end up ringing one.
6. Check the coils are clean
Dusty, greasy coils are one of the most common reasons a fridge can’t shift heat, and it’s worse in summer. A soft brush and a couple of minutes can make a huge difference. We’ve explained how to do it safely in our maintenance guide, so we won’t go over it all again here.
When It’s a DIY Fix and When to Call the Engineer
Those checks cover the everyday stuff, and they’ll fix most warm-fridge problems in hot weather. Do them yourself and you’ve saved a call-out fee. During this recent heatwave our engineers couldn’t keep up with their calls and just instructed businesses to do these checks before calling again, so they’re well worth doing.
Some things aren’t a DIY job though, and having a go usually costs more in the long run. Ring an engineer if:
- The fridge keeps tripping the electrics.
- It runs non-stop but never gets cold, and the coils and seals are fine.
- You can hear the compressor clicking on and off, or it’s gone silent altogether.
- The same fault or error code keeps coming back after a reset.
- You think there might be a refrigerant leak. That’s one for a qualified engineer, never a DIY fix.
One tip from years of doing this is to keep a simple note of what’s gone wrong and when. If the same fridge lets you down every summer, it might work out cheaper to replace it than keep patching it up. NCE can help you with this 😊.
Keeping Your Food Safe While You Sort It
While you’re sorting the fridge, keep half an eye on your food. By law, chilled food has to stay at 8°C or below, and we’d say aim for 5°C or under to give yourself a bit of breathing room.
If the fridge has been warm for a while, use a probe to check whether the food itself has actually warmed up, not just the display reading. Anything high-risk, move it into a fridge you trust while you deal with the faulty one.
For the full story on fridge and freezer temperatures, and how to hold them steady through summer, we’ve got a whole guide on what temperature your commercial fridge should be.
Before You Pick Up the Phone
A warm fridge in a heatwave may seem like it’s broken, but it usually isn’t. Most of the time it comes down to airflow, a tired door seal, a knocked thermostat, or a fridge being asked to work in a room that’s simply too hot for it.
Run through the checks first. You’ll fix a good number of problems in minutes, and even if you don’t, you’ll know exactly what to tell the engineer.
We’ve also put all these checks into a free one-page PDF you can print off and keep by the fridge or hand to staff, so anyone on shift can run through them in a hurry. Download the Fridge & Freezer Troubleshooting Checklist.
Need a fridge that can handle a hot kitchen, or have any other questions? We’re always happy to help. Get in touch.
Best wishes,
Norman and Richard
Frequently Asked Questions
Why is my commercial fridge not cooling in hot weather?
When a kitchen gets very hot, the compressor has to work harder to get rid of heat, and if it overheats it shuts off on a safety cut-out. Blocked airflow, dirty condenser coils, a worn door seal, or a fridge running outside its climate class rating all make this worse. Most of these you can check and fix yourself before calling an engineer.
What checks should I do before calling a fridge engineer?
Check the power and thermostat, make sure the fridge has space around it and isn’t next to anything hot, test the door seal with a banknote, look for ice building up at the back, and try turning it off at the wall for ten minutes to reset it. These cover most warm-fridge problems in hot weather. See above for details.
What temperature should a commercial fridge be in the UK?
By law, chilled food must be kept at 8°C or below. In practice, set your fridge to 5°C or under, with most caterers aiming for 2°C to 4°C. Freezers should be at -18°C or below.
What is a fridge climate class?
It’s the highest room temperature a fridge is built to work in. Class 3 handles up to 25°C, Class 4 up to 30°C, and Class 5 up to 40°C. Most UK kitchens need at least a Class 4, and a hot, busy kitchen is better off with a Class 5.
Why is there ice building up at the back of my commercial fridge?
Ice on the back wall usually means the defrost system isn’t keeping up. The ice blocks the airflow, so the fridge can’t cool properly. As a temporary fix, switch it off and let the ice melt fully. If it comes back within a few days, the defrost parts need an engineer.
How do I reset a commercial fridge?
Turn it off at the wall, leave it for about ten minutes, then turn it back on. This often clears an error code and resets the electronics. Give it a few hours to bring the temperature back down. If the same code returns, note it and call an engineer.
My commercial fridge is running but not getting cold. What’s wrong?
Usually it’s a fridge that can’t get rid of the heat it’s removing. Check for dirty condenser coils, poor airflow around the unit, a door seal that isn’t sealing, or ice at the back blocking the cold. If all of those are fine and it still won’t cool, it could be the compressor or refrigerant, and that needs an engineer.
When should I call an engineer instead of fixing it myself?
Call an engineer if the fridge keeps tripping the electrics, runs constantly but never gets cold, makes the compressor click on and off or go silent, keeps showing the same fault after a reset, or if you suspect a refrigerant leak. Those aren’t safe or sensible DIY jobs.