If your air con has gone weak before, a re-gas alone often won't fix it for long — the gas is escaping somewhere. A leak test finds where before you pay for more gas that leaks straight back out. First time it's felt weak? A straight re-gas is usually the right first step.
Why would air con need a leak test, not just a re-gas?
Air con is a sealed system. Properly sealed, it shouldn't lose gas at all, year after year. If it's gone weak, that gas has gone somewhere — a worn seal, a tiny crack in a pipe, a perished O-ring. Re-gassing without finding that point just refills a system that's going to leak out again, sometimes within weeks.
How do you actually find an air con leak?
Two common ways. A UV dye can be added to the system, which glows under a UV light at the exact point it's escaping. Or an electronic sniffer is run along every joint, pipe and seal in the system, picking up the refrigerant gas in the air at concentrations far too small to smell. Both are far more reliable than guessing from where the compressor sits.
What are the signs I might have a leak, not just old gas?
Gas doesn't just quietly weaken on a fixed schedule — a system that's merely "getting old" tends to still cool well, just slightly less sharply. If the air con was ice cold last summer and is barely cool now, or it was re-gassed within the last year or two and has already gone off again, that pattern points to a leak rather than ordinary gradual loss.
Is R1234yf or R134a different for leak testing?
The testing method is the same either way — dye or electronic sniffer both work on either gas. What differs is the gas itself and the fittings it uses, which is why it matters which one your car takes before any work starts. Most cars built from around 2017 onwards use R1234yf; most older cars use R134a.
Can a leak be fixed, or does it mean a new part?
Depends entirely on where it is. A perished O-ring or a loose fitting is often a straightforward seal replacement. A corroded condenser or a cracked pipe usually means replacing that part. There's no way to know which one applies to your car without actually finding the leak first — which is the whole point of testing for it rather than just re-gassing again.
What does ONEFIX do if a leak test finds a fault?
We quote any repair in writing before doing anything further — nothing gets fixed, and nothing gets charged, without you agreeing the price first. If the leak test comes back clean, or the leak is something small and cheap to put right, you'll know that before any extra work goes ahead, not after.
Should I just get a re-gas and see what happens?
If your air con has never given you trouble before and has simply faded gradually over a couple of years, a straight re-gas is a reasonable first step — that's normal, not a leak. A re-gas with R1234yf costs £102.00 inc. VAT, or £54.00 inc. VAT with R134a. If it goes weak again within a few months of that re-gas, that's the point to ask for a leak test rather than re-gassing again. We've covered what a re-gas actually involves here: air con recharge in Wrexham, and pricing detail here: how much is a re-gas.
Ready to book?
ONEFIX is at Plas Acton Garage, 282 Chester Road, Wrexham, open Monday to Friday, 9am to 5pm. Book an air con check online or call 01978 356983.