1. AMC charges for Split or Window AC - Rs. 1200 (Includes 4 free services + spares if any)
2. Gas top up for Split AC will cost anywhere between Rs. 1000 to Rs. 1500
3. Complete Gas refilling or recharging for Split AC and fixing the leak will cost around Rs. 3000. (3 Months Guarantee)
If you are looking for a reliable person around Chennai to repair your AC you can get in touch with Mr. Viswasam from Ashwyin Aircon, Nandhanam, Chennai - 35. Mobile no. 9380003747. A straight forward person who has been maintaining 4 ACs in my parents property for the past few years.
If the pressure of gas inside your 1.5 ton Air Conditioner is less than 65 PSI, then it's time to refill or top it up.
A very difficult task in India is to get the right quote for the job to be done. When I inquired about AC mechanics around Kilpauk, JustDial guy gave me random options through SMS, which were actually located on the other side of the city. Few guys called me instantly and offered me their services for a variety of cost. 1st Guy told me Rs. 3000 to check, service, fill and weld the gas leak area, price included transportation. 2nd guy's quote was Rs. 350 to identify the mistake and Rs. 800 to fill the gas. 3rd person said Rs. 1800. The last guy who called me the next day was kinda realistic, he said Rs. 650 for gas top-up and Rs. 350 for general service. Incase there is a major leak in the unit, he promised to fix everything for Rs. 2400 (Transportation, Welding etc.,) . I agreed and asked him to send his guys.
"..the cost to refill / repair and weld AC gas leak for a 1.5 ton split AC is Rs. 1800 (Avg) cleaning and transportation charges are extra. If it is just a Gas top up it costs only Rs. 650."
"Ideally the pressure for a 1.5 ton AC should be between 65 - 70 PSI while the AC is running, but mine was only 20 PSI"
Wasn't really laborious, they have a small Air pressure checking 'kind of' meter, which when attached to the highlighted vent showed the pressure inside AC unit. Ideally the pressure for a 1.5 ton AC should be between 65 - 70 PSI while the AC is running, but mine was only 20 PSI. So he took this small cylinder, in the size of a water jug and connected it to the same vent through which he measured the pressure. Withing 5 minutes the gas was transferred in to the AC and it started showing some results. I was able to see the difference instantly and it was much better. He also cleaned all the dust around the condenser, fan etc. So I spent Rs. 1000 in total to get the AC repaired.
The process is much different if it is a Window AC which does not have refill vents like Split. So the AC has to be taken to the workshop and the connections have to be manually cut and welded. So the expense to recharge gas in window AC is always around Rs. 2000 or more.
If the problem persists even after Gas refill, it is better to call the brand's engineers and ask for a thorough analysis and fix.
UPDATE - 20th March 2014
My Split AC has given up. There's no cooling once again, so the gas top up has lasted for about 8 montths. I called the same Vendor (O2 air conditioning), their charges have gone up by Rs. 50. They said Rs. 700 for Gas top-up. I also enquired the charges for 1 and 1.5 ton Window AC Gas Refill, it is Rs. 2,800 for each and they offer 6 months guarantee. As mentioned above, the window unit has to be taken to the shop and repaired unlike the Split ACs, which can be refilled in your door step.