Air conditioning repairs in Waterlooville: Tell us what it's doing. We'll find out why.

Check first

1. Check the mode on the remote - usually a snowflake for cooling and a sun for heating. Fan and Dry modes won't heat the room or cool it properly.
2. Set the temperature a few degrees past the room's: lower to cool, higher to heat.
3. Clean the filters. Switch off, lift the front panel and slide them out; most rinse clean under a cool tap. Let them dry before refitting.
4. Make sure nothing is blocking the outdoor unit - leaves, covers, bins or plants.
5. Close the doors and windows to the room.

What we look for

• Dirty coils restricting the airflow
• A refrigerant leak - the charge never gets used up, so low refrigerant almost always means a leak
• A failing fan motor, sensor or control board
• A unit that's simply too small for the room

Check first

1. If water is near sockets or electrics, switch the unit off at the isolator and keep the area dry.
2. Clean the filters - a clogged filter can freeze the coil, which then drips as it thaws.
3. If you can reach it safely, check the outside end of the drain pipe isn't blocked, crushed or kinked.

What we look for

• A blocked drain or drain tray - dust and algae build up over time
• A failed condensate pump, if the system has one
• A unit that's dropped out of level on its bracket
• Low refrigerant making the coil ice up

Check first

1. Switch it off and let the ice melt completely. Running it iced up only makes things worse.
2. Clean the filters, and check curtains or furniture aren't blocking the indoor unit.
3. In winter, frost on the outdoor unit while it's heating is normal. It defrosts itself every so often, sometimes with a puff of steam.

What we look for

• Restricted airflow from dirty filters, coils or a slow fan
• Low refrigerant from a leak
• A faulty temperature sensor or defrost control

Check first

1. A light click or creak when it starts or stops is normal - the plastic panels expand and contract.
2. A soft whoosh or trickle is the refrigerant moving. Also normal.
3. Check the front panel and filters are clipped fully home.
4. Look for leaves, twigs or anything loose around the outdoor unit.

What we look for

• Worn fan motor bearings - grinding or squealing
• A fan blade catching on debris or ice
• Loose brackets, panels or pipe clips - rattling or vibration
• Electrical parts - loud buzzing or repeated clicking outside

Check first

1. A musty, damp smell usually means mould or bacteria on the filters, coil or drain tray. Clean the filters as a first step.
2. Let the unit run on fan for a while after cooling. Some units have a self-dry or clean setting that does this for you.
3. A burning or electrical smell is different: switch off at the isolator straight away and don't use it again until it has been checked.

What we look for

• Mould on the indoor coil and fan, cleared with a deep clean and antibacterial treatment
• A blocked drain tray holding stale water
• Overheating wiring or electrical parts, if the smell is burning

Check first

1. Put new batteries in the remote, and check it isn't set to a timer or a lock mode.
2. Check the breaker or fuse in your consumer unit, and the isolator switch near the outdoor unit.
3. Write down the code or the pattern of flashing lights first. Then switch off at the isolator for five minutes and back on - some faults clear with a reset; if the code comes back, it's a real fault.
4. Photograph the label on the side or underneath of the indoor unit, so we have the make and model.

What we look for

• Whatever the code points to - sensors, fans, the link between the two units, or a protection trip
• Power supply and wiring problems
• Control board faults