Before you all start about ringing a plumber I am prefectly competent at plumbing.
I am moving a washing machine from my parents kitchen into their garage.
I would normally always fit a U bend to stop the drain smells running back. In the garage the waste pipe will exit through the exterior wall into an open drain with an air gap so I shouldn't need a U bend in the waste pipe.
I am thinking of avoiding a U bend in the waste pipe just incase it freezes. The garage is detached and fairly draughty. I will insulate and lag all feed pipes.
Appreciate any suggestions.
Pressure ok? Garage sounds like it might get cold.. Good idea to have water freezing in the machine?
Pressure is fine, not sure how that is relevant.
I am probably worrying about nothing.
It is worth mentioning that they live in Exeter in Devon in the city. I can't beleive that the residual water in the machine will ever freeze but I did think that the U bend attached to the exterior wall may cause problems.
the waste pipe will exit through the exterior wall into an open drain
Sounds like you plan to run wastewater into a storm water drain. Don't, there's prolly some regulations about this.
Plus all the stuff about freezing.
Drain is a sewage / waste water drain not storm water. Their used to be a sink in the garage at some point many many years ago.
Yep, if it's just a washer, I can't see a big deal, but then I put a U bend in mine (unheated utility) with an eye on creepy crawlies climbing in rather than smells. Mine has a drop from the end into an older drain gully too.
Mines in the garage exactly as you describe; pipes froze solid during the extended cold spell that we had last year, despite more lagging than an iphone 4 entering text on STW. Proper proper pain in the arse, it was.