Air conditioning faults diagnosed properly, not guessed at
A unit that won't cool on a warm night, an office that's stuffy by mid-afternoon, a steady drip down the wall. In each case the thing you can see is rarely the whole story. Poor airflow can cause ice, the ice can cause leaks, and a refrigerant problem can look a lot like a fan fault. Swapping parts on a hunch costs money and often leaves the real cause where it was.
Teesside Air Conditioning repairs domestic and commercial systems right across the area, from wall-mounted units in Stockton and Thornaby homes to cassette systems in Middlesbrough and Hartlepool shops and offices. We work through the system logically, show you what we find and give you clear options. If a repair isn't good value, we'll say so.
Below you'll find the most common faults, what usually causes them, a few simple checks you can safely make yourself and how we decide between repairing and replacing. Would you rather talk to someone now? Call 0191 743 9144 and describe what the unit is doing.
- Most common causes
- Dirty filters, blocked drains, sensor and fan faults
- Before you call
- Note any error code and what the unit is doing
- Refrigerant work
- Must be done by an F-Gas certified engineer
- Quote
- Repair options explained before work goes ahead
Air conditioning symptoms and what usually causes them
Most faults show up as one of a small number of symptoms. Each one has several possible causes, so we test first and order parts second.
Why is my air conditioning running but not cooling or heating?
Rule out the easy things first. It could be in the wrong mode, the room may already be at the set temperature, or the filters may be so clogged that hardly any air gets through. Past that, the usual suspects are a dirty indoor or outdoor coil, a failing fan motor, a faulty temperature sensor, a compressor or inverter board fault, or a low refrigerant charge caused by a leak.
Water leaking from the indoor unit
As air conditioning cools, it pulls moisture out of the air. That condensate should drain away through a pipe or pump. Leaks normally come from a blocked drain line, a dirty or cracked drip tray, a pump that has failed or a drain that has lost its fall. Ice that builds up on the coil and then melts can also overwhelm the tray.
Ice on the coil or pipework
Restricted airflow
Blocked filters, a dirty coil or a sluggish indoor fan let the coil get too cold, and moisture freezes on it.
Low refrigerant
A leak drops the pressure in the system, which can frost up the indoor coil or the smaller pipe at the outdoor unit.
Sensor or control faults
A faulty coil sensor can stop the unit protecting itself against freezing.
Normal defrost in heating
Some frost on the outdoor unit in cold, damp weather is normal. The unit should clear it with regular defrost cycles.
Noises, smells and short cycling
- Rattling or buzzing: loose panels, worn anti-vibration mounts, debris in the outdoor fan or a component on its way out
- Squealing or grinding: often a worn fan motor bearing, best looked at before it seizes
- Musty or damp smells: mould and bacteria on the coil, fan or drip tray, or a drain that's slow to clear
- Burning or electrical smells: switch the system off at the isolator and have it checked before you use it again
- Short cycling: the unit switching on and off every few minutes, which can point to oversizing, a sensor fault, poor airflow or a refrigerant issue
Why a methodical repair saves money in the long run
The real cause is fixed
We test before replacing anything, so the underlying problem gets dealt with and not just the symptom.
No surprises on cost
You know what's wrong and what the repair involves before any work starts.
Leaks repaired properly
We find and fix refrigerant leaks before recharging, so the repair lasts.
Honest repair or replace advice
If an older system isn't worth spending more on, we'll tell you plainly.
Homes and workplaces
We repair wall-mounted units at home and larger systems in offices, shops and other commercial premises.
Advice to prevent a repeat
After the fix, we explain what probably caused the fault and how to make it less likely to happen again.
Error codes, remote problems and PCB or sensor faults
Modern units keep an eye on themselves and show error codes on the indoor display, as flashing lights or through the remote. Codes differ between manufacturers and even between models, so the same code can mean different things. A code tells us where to start testing (a sensor, the communication link between indoor and outdoor units, a fan or the inverter). It rarely names the failed part outright.
Control problems are common too. If a unit ignores the remote, switches itself off or reads the wrong room temperature, the cause could be the remote or its receiver, a failed thermistor, a loose connection or a fault on a printed circuit board (PCB). Near the coast in Redcar or Seaham, electronics in older outdoor units can also corrode over time.
Simple checks you can safely make first
A few quick checks can sometimes sort the problem out, or at least save time once an engineer is on site. Only do what you're comfortable with. Switch the unit off before touching anything, and never open the outdoor unit or any electrical panels. If none of this helps, get in touch with the details you've noted.
- Put new batteries in the remote and check the mode, fan speed and set temperature
- Check the circuit breaker and isolator. Reset a tripped breaker once only, and leave it off if it trips again
- Lift the front cover and gently clean the filters, following the manufacturer's instructions
- Make sure the outdoor unit is clear of leaves, covers, plants and stored items
- Look at where the condensate drain comes out outside and see if water appears when it's cooling
- Write down any error code or flashing pattern and roughly when the problem started
What affects the cost of an air conditioning repair?
The cost of a repair depends on what's actually wrong, so Teesside Air Conditioning doesn't quote fixed prices before the system has been diagnosed. Once we've tested it, we explain the fault and tell you what the repair will cost before we do it.
Some faults are sorted on the first visit. Others need a part ordered in or a return trip for refrigerant work. Regular air conditioning servicing avoids a lot of the most common call-outs, and you can see everything else we do in our full range of air conditioning services.
The nature of the fault
Clearing a blocked drain is a very different job from replacing a fan motor, PCB or compressor.
Parts and availability
Manufacturer parts vary in price, and some older models need parts tracking down or ordering in.
Refrigerant work
Finding and fixing a leak, pressure testing and recharging all take time and specialist kit.
System type and access
Ceiling cassettes, ducted units and high-level outdoor units can take longer to reach and work on.
Number of visits needed
If a part has to be ordered or more testing is needed, the job may take more than one visit.
Refrigerant leaks need finding, not just topping up
The refrigerant in an air conditioning system sits in a sealed circuit, so it shouldn't lose any gas in normal use. A low charge means a leak, often at a flare joint, a brazed joint, a damaged pipe or a corroded coil. Re-gassing without finding it just means the problem comes back, and more refrigerant escapes into the atmosphere.
A proper repair means finding the leak, fixing it, pressure testing the circuit, evacuating it and recharging to the correct weight. We do this for homes and businesses across Teesside and the surrounding areas. In the UK the work must be carried out by F-Gas certified engineers, so ask anyone working on your system to show you their certification.
Is it worth repairing an old air conditioning system?
Plenty of repairs are obviously worth doing: a blocked drain, a dead sensor or a fan motor on a reasonably modern unit. It gets harder with older equipment, a big component like the compressor, or a system using a refrigerant that's being phased down and getting harder to find.
What we weigh up with you
- How old the system is and its overall condition, not just the part that failed
- Whether parts are still available and how long they might take to arrive
- The refrigerant type and the likely cost of any refrigerant work
- How much more efficient a modern inverter system would be
- If the original system was correctly sized for the room to begin with
Getting an honest recommendation
If a repair makes sense, we'll tell you. If putting more money into an ageing unit looks like poor value, we'll explain why and go through air conditioning replacement options instead. It's always your decision.
