I've had a recurring problem for years where I get icy water dribbling into the passenger footwell (RHD). Condensation accumulates on the A/C evaporator & is collected by a drip tray. This drip tray has a spigot at each end to which a rubber drain is attached thence disappearing through the floor to drip out on the road. At leasts that's the theory. These drains have a tendency to get blocked with leaves & crud from the roads. Normally you wriggle under the car & poke a screwdriver or piece of stiff wire into the bottom of the drain & get rewarded with a wet sleeve as the drain is cleared. I previously cleared the drains but with the humid & very hot weather we have been having recently it's started dripping icy water again.

I removed the bits of trim on either side so I could see to disconnect the rubber drain tubes that attach to the spigots at the bottom of the drip tray. I didn't have any suitable wire so was very grateful to my wife who suggested using some of that wire that is normally used to hang net curtains. She even found some in the French DIY store that we visited. The spring wire is perfect as it's flexible but stiff enough to easily push down through the drain tube until it was visible under the car. I hardly needed to scrabble under the car to confirm the drain was patent.

The rubber tube that connects to the spigot is corrugated & I it looks like both tubes have a hole in them but on the upper surface so probably not responsible for the icy water in the footwell. It only happens on the hottest most humid days when the A/C is working hard & presumably lots of condensation is collecting on the evaporator. It's possible that the rubber tubes had been kinked so impeding water flow which in turn means the water backs up in the drip tray & then spills over into the heater box. I have reattached them & as far as I can see they are not kinked so any water from the drip tray should run freely out down through the drains.

I will see how I get on now that I know for sure that the drains are clear & that the rubber tubes reattached to the spigots so there should be clear flow. The problem is that as it's only on the hottest most humid days when the A/C is working hard that the problem occurs the rest of the time I have no idea whether I have fixed the problem or whether it's just not hot &/or humid enough that sufficient condensation collects on the evaporator to start dripping into the cabin.

I would be grateful for any suggestions.

I found on mine that the drain tubes weren't a nice tight fit onto the spigots so when it was really humid it was coming out faster than it could get out of the tubes so would drip. It's a fiddly job, but see if you can get a tie wrap around it and pull it tight. I used a pair of long nosed pliers to get it into place and pull the tie wrap tight. I've had no further reports of wet feet since.

Gilbertd wrote:

I found on mine that the drain tubes weren't a nice tight fit onto the spigots so when it was really humid it was coming out faster than it could get out of the tubes so would drip. It's a fiddly job, but see if you can get a tie wrap around it and pull it tight. I used a pair of long nosed pliers to get it into place and pull the tie wrap tight. I've had no further reports of wet feet since.

I will give that a try when I get back to the UK as I know I have some fine cable ties plus several pairs of surgical forceps that will aid fitting. It will be like doing keyhole surgery😀

I still wonder if that could be the cause of my problems as even if I completely disconnected the drain tubes from the spigots the water would then drip (or pour) down underneath the carpet either side of the tunnel. What I get is water in the heater ducts. Once it's reached a certain critical level I can hear it sloshing about & it spills out when cornering. It's the same symptoms as when rainwater is getting into the heater ducts round the pollen filters. Which reminds me I need to investigate the water ingress the last time I was out in torrential rain. There has been no significant rain for several months so this is not my current issue plus the water entering the cabin is icy.

If it is really humid and the drains are partially blocked, the condensation can't drain fast enough and it will flow into the intake trunking. Then there is a convenient join in the duct for it to dribble out of. Sealing that is a good idea too while you are in there. I cleared my drains with a spare length of 6mm EAS pipe but the spiral curtain wire should do the same job nicely.