A new AC that never cools properly is usually not a faulty machine. It is an installation done in a hurry — wrong outdoor placement, no vacuum pulled, a drain running the wrong way, or a socket that was never earthed.
We get called out every summer to units that are barely a year old and cool badly. In most of those cases the machine is fine. The installation was rushed, and the household has been paying for that rush ever since in weak cooling, high bills and repeat repairs.
Installation is a few hours of work done once. It decides how the unit behaves for the next ten years. Here is what goes wrong, and what a correct job looks like.
Placement: where the two units end up
1. The outdoor unit put somewhere convenient rather than somewhere sensible
The outdoor unit exists to dump heat into the air. If it cannot, cooling drops and the compressor runs hot for its whole life.
The bad placements we see most often: pushed into a narrow shaft between two buildings, boxed in behind a decorative grille, tucked under a staircase, placed on a terrace facing the full afternoon sun with no shade, or two units mounted face to face so each one breathes the other's hot air.
Correct: roughly a foot of clear space at the back and sides, nothing blocking the front where air is thrown out, a shaded or at least partly shaded spot, and a firm bracket bolted into sound masonry. If the only available spot is baked by the sun, a simple shade over it — not touching it, not boxing it in — helps.
2. Indoor unit placed where the air cannot go anywhere
The indoor unit needs a clear throw across the room. Mounted directly above a tall almirah, right beside a door that is opened constantly, or squeezed under a false ceiling with no clearance, it will short-cycle on its own cooled air and leave the rest of the room warm. It should also be slightly tilted towards the drain side so water runs out rather than pooling.
Pipe work
3. Pipe run longer than it needs to be
People often want the outdoor unit far away so the noise is out of earshot. Every extra metre of copper adds resistance and, past the standard length, needs extra refrigerant to compensate. Long runs installed without that adjustment cool poorly from day one and nobody ever works out why.
Correct: keep the run as short as the layout allows. If a long run genuinely is necessary, the technician should say so, allow for it, and tell you before the drilling starts.
4. Too many bends, and bends made badly
Copper pipe should be bent with a bender or by hand in a wide, smooth curve. A pipe kinked over a knee has a flattened section inside that restricts flow permanently. You cannot see it once the insulation is taped up.
5. The drain pipe running uphill
This is the single most common cause of an indoor unit dripping onto the wall. Condensate drains by gravity alone. The pipe must fall continuously from the indoor unit to where it empties — no dips, no loops sitting in a pool of water, no rise over a window frame.
Correct: a steady downward slope the whole way, the outlet clear of the wall so water does not run back along the plaster, and the pipe checked with water before the job is called finished. In our area drain pipes also silt up quickly because of dust and hard groundwater, so an accessible route matters.
The refrigerant side
6. No vacuum pulled
This is the one that costs the most and shows the least. Before refrigerant is released into the pipes, the air and moisture inside the new pipe run must be pulled out with a vacuum pump. It takes time, which is exactly why it gets skipped.
Instead, some installers "purge" — cracking the valve briefly to blow air out with refrigerant. That leaves moisture behind. Moisture inside a sealed refrigerant circuit reacts with the oil, forms acid, blocks the capillary and slowly kills the compressor. The unit works fine for a season or two, then fails in a way nobody connects back to installation day.
Watch for this on the day: a proper installation uses a vacuum pump, and you can see and hear it running for several minutes before the gas valves are opened. If nobody brings a vacuum pump to your house, the job is not being done correctly — ask before they start, not after.
7. Flare joints made carelessly
The copper ends are flared and tightened onto the valves. A flare cut at an angle, cracked, or over-tightened will seep refrigerant slowly. That is the leak behind "we filled gas last year and it is low again". A proper installer checks the joints for leaks after charging.
Electrical shortcuts
8. Wrong stabiliser, or none at all
Voltage in much of Rohtas and Kaimur sags on summer evenings, exactly when the AC is working hardest. A compressor repeatedly attempting to start on low voltage draws heavy current and heats its windings.
Two mistakes here: fitting no stabiliser at all, and fitting one rated for a smaller load because it was cheaper or already in the house. A stabiliser must match the unit it is protecting, and it must be sited where it gets air, not inside a cupboard.
9. Power point and earthing treated as an afterthought
An AC needs a dedicated point with cable sized for the load, a proper switch, and real earthing. What we find instead is an AC on an extension board, sharing a socket with a fridge, or connected to an earth wire that goes nowhere.
Poor earthing is a shock risk on a metal-bodied outdoor unit, and a loose or undersized connection heats up until the terminal block burns. Both are avoidable in an hour at installation and expensive afterwards.
What a correct installation looks like
- Outdoor and indoor locations agreed with you before any drilling.
- Shortest sensible pipe run, smooth bends, insulation taped along the whole length.
- Drain checked with water and falling all the way.
- Vacuum pulled with a pump before the valves are opened.
- Flare joints leak-checked after charging.
- Dedicated point, correct stabiliser, earthing confirmed.
- Cooling checked by measuring the temperature difference across the indoor coil before the technician leaves.
- A bill for the work.
Installation charges are on the rate list, with GST extra, materials billed at actual cost after we tell you the price, and travel charges beyond 5 KM. The range of work we take on is listed on the services page.
We install and repair across Sasaram, Dehri-on-Sone, Bikramganj, Kudra and Aurangabad, with the full list on the service areas page. To book, call +91 96315 11974 or use the contact page — we ring back within an hour.
Frequently asked questions
Yes, and it is the step most often skipped. Air and moisture left in the new pipe run react with the compressor oil, form acid and block the capillary, which kills the compressor over a couple of seasons. Blowing the line out with refrigerant instead of pumping it down is not the same thing. Ask to see the vacuum pump.
Almost always the drain. Either the pipe rises somewhere along its run instead of falling continuously, it has a dip holding water, it is already silted up, or the indoor unit is not tilted slightly towards the drain side. All four are installation faults and all four are fixable without touching the refrigerant circuit.
Roughly a foot of clear space at the back and sides so it can draw air in, and an unobstructed path in front where the hot air is thrown out. Keep it out of a narrow shaft, out from behind solid grilles, and away from a second outdoor unit facing it. Partial shade helps in our summers.
Yes. An AC should have its own point with cable sized for the load and a proper switch, never an extension board or a socket shared with a fridge. Earthing matters because the outdoor unit has a metal body. A loose or thin connection heats up until the terminal block burns, which turns a wiring job into a repair.
Want a hand with this?
Book a technician at home across Sasaram, Rohtas, Kaimur and Aurangabad. Prices fixed up front, a bill for every job.