01
Airflow has gone weak
Usual cause
Loaded filters and a dust-matted evaporator coil restricting the air path.
Typical work
Filter wash, coil clean and blower check. A standard service resolves most cases.
Residential & light commercial
Cold air is a maintenance outcome, not a lucky one.
Stone Grain services split, cassette and window units: filter and coil cleaning, chemical washes, drainage clearing and fault diagnosis — booked as a fixed window, with the work explained before anything is opened.
- Licensed handlingRefrigerant work is carried out only by technicians certified to handle it.
- Three service depthsStandard clean, chemical wash and full overhaul — chosen after inspection, not before.
- Evening & weekend windowsHeld for occupied homes and tenanted units where daytime access is difficult.
Start here
What the unit is telling you
Most calls begin with one of six complaints. Here is what each usually means and the work it normally leads to, so you know what you are booking before a technician arrives.
02
Water dripping indoors
Usual cause
A blocked condensate line or a drip tray holding sludge and biofilm.
Typical work
Drain flush, tray clean and gradient check on the condensate run.
03
Musty smell on start-up
Usual cause
Microbial growth held in the coil fins and tray between cooling cycles.
Typical work
Chemical wash of coil, tray and blower wheel — surface cleaning will not reach it.
04
Ice forming on the pipework
Usual cause
Low refrigerant charge or airflow starvation dropping coil temperature too far.
Typical work
Pressure test and leak trace first; charge is only corrected once the loss is found.
05
The breaker trips when it runs
Usual cause
A failing capacitor, a stressed compressor start, or a shared circuit under load.
Typical work
Electrical diagnosis with current readings before any component is replaced.
06
Rattle, hum or vibration
Usual cause
Loose mounting, debris against the fan, or worn bearings in the outdoor unit.
Typical work
Mounting and fan inspection at both units, with a noise reading taken under load.
If the unit is icing or tripping a breaker, switch it off at the wall and note the time it happened — it shortens the diagnosis considerably.
Service depths
Three levels of clean
The right level depends on how long the unit has run since its last service and what the inspection finds. We confirm the level with you on site before the work starts.
Standard service
Routine upkeep for units that are cleaned on schedule and still cooling normally.
- Filter removal, wash and refit
- Front panel and fascia wipe-down
- Drip tray and drain line flush
- Outdoor coil rinse and debris clear
- Cooling temperature reading at the vent
Chemical wash
For units with smell, weak airflow or visible fin loading that a standard clean will not shift.
- Everything in the standard service
- Chemical treatment of the evaporator coil
- Blower wheel cleaned in place
- Drain line cleared under pressure
- Post-wash airflow and drainage check
Chemical overhaul
A dismantled clean for neglected units, long tenancies, or systems being handed over.
- Indoor unit removed from the wall bracket
- Casing, blower and coil washed off-wall
- Full drainage path cleared and tested
- Electrical terminals and capacitor checked
- Refrigerant pressures read and recorded
On the day
What a visit looks like
Every window follows the same order, so you can plan access and know what is left behind when we go.
-
01
Sheeting and access
Floor and furniture below each unit are covered before a panel is opened. We work from our own ladder and containment sheet.
-
02
Inspection and readings
Airflow, vent temperature, drainage fall and outdoor fan condition are checked and noted before cleaning begins.
-
03
Level confirmed with you
If the inspection points to a deeper clean than booked, we explain why and wait for your decision. Nothing is upgraded silently.
-
04
The clean itself
Filters, coil, blower and drainage are worked in sequence, then the outdoor unit is rinsed and cleared.
-
05
Run test and hand-back
The system runs for a full cycle while drainage is watched. You get the readings, anything we flagged, and the date the next service is due.
Planning ahead
How often, by how you use it
Service intervals follow running hours and air quality far more than the age of the unit. Use the pattern closest to yours as a starting point.
Bedroom unit, nightly
Long overnight runs at low fan speed let moisture sit in the tray until morning.
Every 3 months
Living area, evenings only
Shorter cycles, but cooking aerosols and street dust load the filters quickly.
Every 4 months
Home office, full weekdays
Continuous daytime running is the heaviest residential duty cycle we see.
Every 2–3 months
Tenanted unit, between leases
Unknown history and long idle periods between occupants.
At each handover
Small shop or studio
Door traffic, foot dust and extended opening hours push filters hard.
Every 2 months
Holiday let or spare room
Light use, but stagnant coils develop smell faster than running ones.
Every 6 months
Before you book
Questions we are asked most
What access do you need on the day?
Clear floor space beneath each indoor unit, a power point within reach, and access to the outdoor unit — a balcony, ledge, yard or service corridor. If the outdoor unit sits beyond a window or above ground level, tell us when you book so the right equipment comes with the technician.
Does every service include a gas top-up?
No, and it should not. A sealed system does not consume refrigerant. If pressures read low, there is a leak, and topping up without finding it simply pays for the same gas twice. We trace the loss first and quote the repair separately.
Can the unit be serviced while the property is tenanted?
Yes. Standard services and chemical washes are done in place with the occupant at home. A chemical overhaul takes the indoor unit off the wall, so it needs a longer window and a clear room — that one is usually scheduled between leases or on a weekend.
Will the unit be quieter after a service?
Often, yes — a clean blower wheel is better balanced and a cleared coil lets the fan run at a lower speed for the same cooling. Mechanical noise from worn bearings or loose mounting is a separate repair, and we will say so rather than let a clean take the credit.
Water keeps returning a few weeks after cleaning. Why?
A recurring leak usually points at the drainage run rather than the tray — insufficient fall, a sagging section holding water, or a blocked outlet outside the wall. We check the gradient across the whole run during an overhaul and flag anything that needs re-routing.
What happens if you find a fault mid-service?
We stop, show you what we found, and give you the options before continuing. The booked clean is completed either way where it is safe to do so. Repairs are never carried out on the same visit without your agreement.
Booking
Request a service window
Send the basics and we will come back with the windows available for your area, the service level we would suggest, and what it covers.
Helpful to have ready
- Unit count and roomsWhich rooms have units, and whether they share one outdoor condenser.
- Last service dateEven an approximate year tells us whether to plan a wash or a standard clean.
- Outdoor unit positionBalcony, ledge, roof or ground — this decides the access equipment we bring.
- When the fault appearsOn start-up, after an hour, or only on hot afternoons. Timing narrows the cause.