A few months ago, out of the blue, our washing machine overflow pipe began overflowing during the wash cycle. :confused: I looked around on the net to try to find solutions and most recommended snaking the pipe which we did, along with flushing some drain cleaner/unblocker down.

This helped, if not resolving the problem entirely (a bucket underneath would catch any overflow and wouldn't fill for a couple of weeks), for a couple of months until again, somewhat randomly, it started flooding the garage. :eek:

Our pipe is a standard configuration. A flexible drainpipe out of the washer into an upright pipe - rested loosely with a hard plastic u-bend. The top of the drain off pipe is the same height as the washing machine and the drain itself feeds through the kitchen, where it joins the dishwasher drainage and out through the drain under the sink to an open drainage hole in the garden. In total, there can be less than 10 metres of pipe between the washer and release.

This weekend we put the hose down the pipe - about half way as there is a 90 degree kink down just after the dishwasher joins the pipe - and the flow was consistent and fine, with the hose coming back out clean to all intents.

I have resisted taping the top of the overflow pipe where the rubber drainpipe from the machine sits, as I have read conflicting reports as to the safety of this - no vent in essence - but surely there must be something that can be done here? Why would this start, as it did, out of nowhere and then despite being snaked and appearing clear return with vengeance? :mad:

Any and all suggestions are greatly appreciated, with two sub 5 year olds the washing machine is a vital appliance, but I can't keep flooding the garage! :(

I have resisted taping the top of the overflow pipe where the rubber drainpipe from the machine sits, as I have read conflicting reports as to the safety of this -

I think you better do what the rest of us do whan we have the same problem.
Today's more powerful pumps can overpower a drainage system that's been working for years. When the happens we advise making your washer drainage a closed system by connecting the washer hose to the stand pipe using a compression fitting, (see image) or simply duct taping it. Any thing you can do to make a air tight connection. The washer pump will force the discharge through to the house main. I have had one on my stand pipe for the last 10 years an three washers with bno backups nor problem to the washer.
In addition, in all the hundreds of askers we have advised to do this we have never- ever had a complaint back. Good luck, Tom

Thanks for this, as I say had heard conflicting reports, but as this was the last thing I could think of trying will certainly do so now.

Ta.

The only reason for you washer stand pipe to overflow now, if it has not previously done, so would be a partial blockage in the drain line. If you ran a garden hose down the pipe as far as the dishwasher, the blockage is between the dishwasher and the drainage pit. However, the volume of water from a garden hose will not equal the volume of the washer pump motor.

I assume that by kink in the line you mean a 90 degree turn. The purpose of a vent pipe is to prevent the siphoning of traps. The purpose of a trap is to prevent sewer gas from entering the home. Sealing an improperly vented washer stand pipe can some times cause problems but it all depends on number of factors.
I am assuming that by a 90 degree kink at the dishwasher you mean a 90 turn. Since you were able to put a garden hose down the drain I am also assuming that you don't have traps on this line. I don't have a problem with that since you are only draining to the outside not into a sewer line or septic tank. The only reason you would need a trap is to keep the creepy crawly things out.
What I am saying with all this is, seal the washer drain hose to the stand pipe. The force of the water may eventually clear the partial blockage. If you have problems with the washer going out of balance, not filling or draining properly, or if you have water backing up to the dishwasher, then remove the seal and snake the entire line. You could also try running the garden hose up the line from the drain pit to the house to clear the blockage.