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I want to wash the unit myself with a garden sprayer – what is the risk?

Editorial guide · Updated 18 September 2026

In short Short answer: it can be done, with real risks – water in the circuit board and fan motor (left or right depending on model), fins flattened by pressure, cracked pan, water on the wall and floor without a proper cover. And crucially, a garden sprayer does not reach the roller or the back of the evaporator, so you remove perhaps 30–40% of the dirt. See current rates on the Prices page.

This page explains a situation in an editorial format. It is not an open discussion board or a verified customer review. Contact us on WhatsApp about your own appliance.

Situation discussed

House in Popești-Leordeni, I am handy. I have a pressurised garden sprayer and want to wash the evaporator of my 12,000 Midea (5 years old) myself, with a sheet of film underneath. What can I break? What do I need to know to avoid ending up with a repair?

Editorial explanation · Revizie AC

What is really happening

The indoor unit is a sandwich: evaporator in front, fan roller at the back-bottom, pan underneath, and on the side (usually right) the electronics box and sensors, on the left the motor. Pressurised water without a sealed cover runs where you do not want it: into the electronics box (short circuit after incomplete drying), onto the wall (stain and mould), onto the floor. Sprayer pressure is too low for mature biofilm and too high, if you bring the nozzle close, for 0.1 mm aluminium fins, which flatten and block airflow permanently. The roller is not reachable without removing the housing and pan, and manufacturers prohibit solvents and accept only neutral detergent. The studies achieving over 99% fungal reduction use alkaline detergent + brushing + pressure rinse on all components – that is not done with a sprayer through the grille. We are not saying 'no'; we are saying what you will get.

Explanatory diagramFilters: check the manual before cleaning
Filters: check the manual before cleaning
  1. Switch off and follow the safety instructions in the manual.
  2. Wash only filters identified as washable by the manufacturer.
  3. Let them dry as instructed before refitting.
What the studies say
  • Washing with alkaline detergent, brushing and high-pressure rinsing reduces fungi inside the unit by more than 99%. [Indoor Air, 2023]
  • Manufacturers prohibit benzine, thinner, scouring powder or insecticide on the indoor unit; only water and neutral detergent are allowed. [Mitsubishi Electric, 2020]
  • The blower (cross-flow fan) is the most fungus-contaminated component of a split unit, more than the filter or the front of the evaporator. [Indoor Air, 2023]
  • EPA principle: mould must be physically removed, not merely 'killed'; biocides are not recommended as routine practice. [US EPA, 2024]

What we do on site

  1. What we do, for comparison: collection cover sealed to the wall, draining into a bucket – not a drop on wall or floor.
  2. Electronics and motor protected; alkaline cleaning solution on evaporator, roller, pan.
  3. Controlled pressure wash, in place, no dismantling, including the roller blade by blade and the back of the evaporator.
  4. Sanitising solution; outdoor unit washed in place.
  5. See current rates on the Prices page.

What you can do yourself

  • If you do try: power off at the breaker, not just the remote; film sealed to the wall under the unit, sloped towards a bucket; bag over the electronics box; nozzle at least 20 cm away, dispersed jet, only the evaporator face, top to bottom; neutral detergent, no bleach; 24 hours' drying before switch-on.
  • What you can do risk-free: filters, louvres, outer housing, hose end.
  • 'Fan' before shut-off, filters every two weeks.

What NOT to do

  • Do not spray towards the left/right where the motor and electronics sit.
  • Do not remove the roller – clips and bearings break, and you end up with a repair costlier than sanitising.
  • Do not switch the unit on wet 'to see if it works'.

Prevention

DIY is good for filters and housing; for evaporator, roller and pan, one visit a year with cover and pressure is safer and more complete.

When to call us

0764 012 943, Monday–Saturday 08:00–20:00. Popești-Leordeni.

Female technician holding a clean filter in the kitchen, portrait format
Female technician holding a clean filter in the kitchen, portrait format
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The information on this page is educational and based on cited sources; it does not replace medical advice. We do not do repairs, installation or refrigerant circuit work.