Hi,
I am having a problem when it gets VERY cold my washer drain and sometimes cold water are freezing. It is on an outside wall. We cut a 12" x 2 ft hole in the drywall to be sure it was insulated... it was... but my husband filled it with the cans of spray foam... it is still freezing... the laundry tub next to it doesn't freeze. The laundry room is on a slab... the plumbing goes to the basement... ANY suggestions?
Thanks
renee

Hi Renee

The washing machine drain has a PTRAP that has standing water in it at all times (keeps sewer gasses out of the home). Here, you may want to consider bringing the PTRAP into the room. This means that you would remove the PTRAP in the wall, offset the drain into the room and install a new PTRAP and then, if needed, offset back into the wall to pick up the washer drain plumbing vent (but only if needed...could be that the vent is piped in a way that doesn't require offsetting back into the room (can discuss more on this if you decide to proceed with the work). The minimum standpipe coming out of the PTRAP is between 18" and 30" in most states.

In terms of the cold water, well again, I would get as much of the water piping into the room as possible and close off the hole in the wall. Be careful with insulation and pipes, too as it can actually keep things cold and make pipes freeze FASTER!

Keep the questions coming, OK?

Mark