Air Conditioning Repairs on Any Major Brand
When air conditioning stops cooling, leaks water or shows an error code, JAC Air Conditioning Ltd finds the fault, tells you the price before work starts and repairs it with genuine parts.
Repairs Across Sussex and Surrey, Whoever Fitted the System
JAC Air Conditioning Ltd repairs air conditioning in homes and businesses across Sussex and Surrey from our office in Horsham, and across Lincolnshire from Fosdyke. We work on every major brand, not only the ones we install, so it does not matter who fitted your system or how long ago.
A good repair starts with a proper diagnosis. Many faults show the same symptom, and a unit that is not cooling might have a blocked filter, a failed fan motor, a faulty sensor or a refrigerant leak. Our engineers find the cause before anything is replaced, so you pay to fix the fault rather than for parts tried until something works.
Once we know what is wrong, we tell you the price before the work starts. Where parts are needed we use genuine manufacturer parts, which fit correctly and keep the system working as it was designed to. For emergencies and out of hours, the engineers' mobile is 07802 418530; for everything else, call the office on 01403 733 492.
What Is Your System Doing?
Choose the symptom closest to yours to see the likely causes, the checks that are safe to make yourself and the point to stop and call an engineer.
Highlighted on the drawing
- Remote control
- Filters
- Refrigerant pipework
- Isolator switch
- Outdoor fan
Highlighted on the drawing
- Remote control
- Filters
- Outdoor coil
- Outdoor fan
Highlighted on the drawing
- Condensate tray
- Condensate drain pipe
- Filters
- Indoor coil
Highlighted on the drawing
- Indoor coil
- Refrigerant pipework
- Filters
- Indoor fan
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- Indoor fan
- Outdoor fan
- Compressor
Highlighted on the drawing
- Filters
- Indoor coil
- Condensate tray
- Indoor fan
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- Control board and indicator lights
- Remote control
- Isolator switch
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- Circuit breaker
- Isolator switch
- Outdoor fan
- Compressor
- Remote control
Not Cooling
Likely Causes
- The remote is set to the wrong mode, or the temperature is set above the room.
- Blocked filters are starving the unit of air.
- The outdoor unit is blocked, or it has stopped running.
- A refrigerant leak has lowered the charge in the system.
- A sensor, fan motor or control board has failed.
What You Can Safely Check
Tick each check as you make it.
0 of 4 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- It still blows warm air after these checks.
- The outdoor unit is silent, or its fan does not turn.
- You see ice or oily marks on the pipework, which can point to a leak.
Not Heating
Likely Causes
- The remote is set to Cool, Dry or Fan rather than Heat.
- The unit is defrosting, which it does now and then in cold, damp weather.
- Blocked filters are starving the unit of air.
- The outdoor coil is iced up or blocked.
- A sensor or valve in the system has failed.
What You Can Safely Check
Tick each check as you make it.
0 of 4 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- It stays cold after these checks.
- Thick ice stays on the outdoor unit and does not clear.
- The outdoor unit runs but the indoor unit only blows cool air.
Water Dripping Indoors
Likely Causes
- The condensate drain or its trap is blocked.
- The drain pipe has lost its fall, or a joint has come loose.
- A condensate pump has failed, where one is fitted.
- Ice on the coil is melting faster than the tray can drain it.
- A dirty filter has led to ice forming on the coil.
What You Can Safely Check
Tick each check as you make it.
0 of 3 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- Water keeps coming once the filters are clean.
- Water is running near sockets, lights or the unit itself: switch off at the isolator first.
- You can hear a pump running all the time, or not at all.
Ice on the Pipes or Unit
Likely Causes
- Low airflow from blocked filters or a slow indoor fan.
- A low refrigerant charge caused by a leak.
- Cooling running on a cool day or a cold night.
- A sensor or expansion valve fault.
What You Can Safely Check
Tick each check as you make it.
0 of 3 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- The ice comes back once the filters are clean.
- There are oily marks around the pipe joints.
- A leak has to be found and repaired by an F-Gas certified company, never just topped up.
Noisy
Likely Causes
- A loose panel, cover or bracket is vibrating.
- Dirt or debris has built up on a fan.
- A fan motor bearing is wearing.
- The compressor is struggling.
- Pipework is touching a wall or another pipe.
What You Can Safely Check
Tick each check as you make it.
0 of 3 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- Grinding, squealing or loud knocking.
- A rattle that gets worse from one day to the next.
- Any noise that comes with a burning smell: switch off at the isolator.
Unpleasant Smell
Likely Causes
- Dust and bacteria building up on dirty filters and the coil.
- Water standing in the condensate tray.
- A musty smell after a long time switched off.
- A burning or electrical smell, which is a different matter altogether.
What You Can Safely Check
Tick each check as you make it.
0 of 2 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- The smell stays once the filters are clean, as the coil and tray may need cleaning.
- Any burning, hot plastic or electrical smell: switch off at the isolator and call.
- You can see mould on the fan or the louvres.
Error Code or Flashing Light
Likely Causes
- The unit has found a fault and stopped to protect itself.
- The indoor and outdoor units have stopped talking to each other.
- A sensor is reading outside its normal range.
- On some models, a reminder to clean the filters, which is not a fault.
What You Can Safely Check
Tick each check as you make it.
0 of 3 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- The code comes back after that one restart.
- The unit keeps stopping. Please do not keep resetting it.
- Codes differ between makes, and we read them against the maker’s own fault information.
Outdoor Unit Not Running
Likely Causes
- The circuit breaker has tripped, or the isolator is off.
- The indoor unit is not asking for cooling or heating.
- The system has stopped itself after a fault.
- A fan motor, capacitor or compressor has failed.
- A wiring or communication fault between the units.
What You Can Safely Check
Tick each check as you make it.
0 of 3 checked.
All checked. If it is still not right, it is time to call us.
When to Stop and Call Us
- The breaker trips again when you reset it: leave it off.
- The fan does not turn but you can hear a hum.
- Any sign of burning, scorch marks or a smell from the unit.
Please never open the casing of either unit. Inside are mains electrics and a refrigerant circuit under pressure, and only an F-Gas certified company may work on refrigerant. If you are unsure, switch off at the isolator and call the office on 01403 733 492, or the engineers’ mobile on 07802 418530 for emergencies and out of hours.
What a Repair Visit Includes
Every repair follows the same order, from finding the fault to proving it is fixed.
Fault Diagnosis
We read any error codes and check the electrics, sensors, fans and pressures to find the cause rather than the symptom.
Price Before Work
You are told what the repair involves and what it costs before we carry it out.
Genuine Parts
Replacement parts come from the manufacturer, so they fit and perform as the originals did.
Refrigerant Leak Repair
Leaks are traced, repaired and pressure tested before the system is recharged, never simply topped up.
Any Major Brand
We repair Mitsubishi Heavy Industries, Mitsubishi Electric, Daikin, Fujitsu, GENERAL, Samsung, LG and other major makes.
Tested Before We Leave
The system is run in cooling and heating and checked, so you know the repair has worked.
Common Faults With Air Conditioning
Air conditioning faults tend to fall into a handful of patterns. Some are minor and quick to put right; others point to a problem that will get worse if the system is left running. These are the common ones, and what they usually mean.
Water dripping from an indoor unit is usually a blocked or poorly laid condensate drain, though it can also follow ice forming on the coil. Ice itself often points to low airflow from a dirty filter, or to low refrigerant from a leak. A new rattle, buzz or squeal can be a loose panel, a worn fan bearing or a compressor that is struggling. Error codes differ between manufacturers, and we read them against the maker's own fault information.
- Not cooling or not heating
- Water leaking from the indoor unit
- Ice on the pipes or coil
- New noises or vibration
- Error codes or flashing lights
- Refrigerant leaks
Simple Checks Before You Call
A few things are safe to check yourself, and now and then they solve the problem. Make sure the remote is set to cool or heat rather than fan or dry, and that its batteries are working. Check that the isolator switch near the unit is on and that the circuit breaker has not tripped. Look at the filters behind the front panel: if they are thick with dust, cleaning them can bring the airflow back. Outside, make sure leaves, bins or garden furniture are not blocking the outdoor unit.
Beyond that, please leave it to us. The casing hides mains electrics, and the refrigerant circuit is under pressure. If a breaker keeps tripping, if you notice a burning smell, or if water is running near electrics, switch the system off at the isolator and call. The answers on our FAQ page cover more of the common questions about faults and what to do next.
Why a Refrigerant Leak Needs a Proper Repair
Air conditioning does not use up its refrigerant. If the charge is low, it has leaked out, and topping it up without finding the leak means it will simply leak out again. In the meantime the system works harder, cools less and can freeze up or damage its compressor.
We trace the leak, repair the joint or component, pressure test the circuit and pull a vacuum to remove air and moisture, then recharge the system with the correct refrigerant by weight. By law, only a certified company may repair a refrigerant circuit. JAC Air Conditioning Ltd holds REFCOM F-Gas company certification, certificate number REF1019419, valid to 25 May 2028, and the work is recorded for you.
Refrigerants also differ in the harm they cause when they escape. R410A has a global warming potential of 2,088 and R32 one of 675, which is one reason a leak should be dealt with rather than ignored.
Repair or Replace?
Many faults are worth repairing, and we would rather fix a sound system than sell you a new one. There comes a point, though, where the honest advice changes. If parts for an older model are hard to find, if the same fault keeps coming back, or if the pipework itself is in poor condition, a replacement may cost less over the coming years than a series of repairs.
When that is the case we explain why, show you what we found, and give you the repair price alongside a written quotation for a replacement so you can decide. If you go ahead, our air conditioning installation work starts with a survey and sizing, so the new unit is chosen for the room rather than simply matched to the old one.
Many of the faults on this page are found early, or avoided altogether, with regular air conditioning servicing.
How a Repair Is Handled
We keep you informed at each stage, so you always know what is happening and what it will cost.
Tell Us the Symptoms
Call or send an enquiry with the make, any error code and what the system is doing, which helps us come prepared.
Diagnosis Visit
An engineer tests the system, finds the cause and explains it to you in plain terms.
Price Agreed
You are given the cost of the repair before any work begins, and nothing is done without your agreement.
Repair With Genuine Parts
We carry out the repair using manufacturer parts and, where refrigerant is involved, test and record the work.
Test and Report
The system is run and checked, and you are told what was done and anything to keep an eye on.
Outstanding service from start to finish. Very confident to recommend this company, extremely professional and friendly. Happy costumer!
Air Conditioning Repairs Questions, Answered
Do you repair air conditioning you did not install?
Yes. JAC Air Conditioning Ltd repairs every major brand, including Mitsubishi Heavy Industries, Mitsubishi Electric, Daikin, Fujitsu, GENERAL, Samsung and LG, whoever installed the system. If you can tell us the make and model, and any error code on the display or remote, it helps us arrive with the right information and, where possible, the right parts.
How much will my air conditioning repair cost?
We cannot give a fair price until we know what is wrong, because the same symptom can have very different causes. Once our engineer has diagnosed the fault, we tell you what the repair involves and what it will cost before any work starts. Nothing is replaced without your agreement.
Why is my air conditioning leaking water?
Water from the indoor unit usually means a blocked condensate drain, a drain pipe without enough fall, or a dirty filter letting ice form on the coil, which then melts. Switch the unit off, keep water away from electrics and sockets, and call us. A blocked drain is often a straightforward repair once it has been found.
Can you just regas my air conditioning?
We can recharge the system, but only after finding and repairing the leak. Refrigerant is not used up, so a low charge means it has escaped somewhere. Topping it up without a repair wastes refrigerant, harms the environment and leaves the fault in place. We repair the leak, pressure test the circuit, evacuate it and recharge by weight.
Who do I call if my air conditioning fails out of hours?
For emergencies and out of hours, call the engineers' mobile on 07802 418530. For repair bookings, quotations and servicing during the working day, call the office on 01403 733 492 or email info@jacairconditioning.com. If a breaker keeps tripping or water is near electrics, switch the system off at the isolator while you wait.
Is it worth repairing an old air conditioning unit?
Often it is, particularly if the fault is a single part such as a fan motor, sensor or circuit board. It becomes harder to justify when parts are no longer available, faults keep returning or the pipework is in poor condition. We give you the honest picture, with a repair price and, where it makes sense, a replacement quotation alongside it.
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Air Conditioning Repairs Across Sussex and Surrey
From the Horsham office we cover Guildford · Godalming · Horsham · Dorking · Brighton · Worthing · Chichester · Bognor Regis · Haywards Heath · Burgess Hill · Billingshurst · Cranleigh · Hassocks · Storrington, and the villages around them, with Lincolnshire covered from our base at Fosdyke. See every area we cover.
Report a Fault
If your air conditioning has stopped working properly, tell us what it is doing and we will arrange a visit. JAC Air Conditioning Ltd repairs systems in homes, offices, shops and server rooms across Sussex, Surrey and Lincolnshire. Call the office on 01403 733 492, use the engineers' mobile on 07802 418530 for emergencies, or describe the fault online and we will be in touch.