Get a front loader. They are far superior Yes, modern washer pumps can overwhelm a 1 1/2” standpipe.

Would love one but with the laundry room configuration they stick out too far and would block the back door 😢

" I'm told I need to get a 2" pipe if I want a new washer (I do!)."

By whom? The new manufacturer?

By the plumber

2" is what code requires, and to physically handle the rate of discharge most modern washers have. Not sure if it's understood, but that 2" includes the standpipe, P-trap, and branch line in the entirety back to the main waste line (given no other fixtures on that branch).

Older houses typically only have 1 1/4" or 1 1/2", and often in galvanized pipe, which can corrode inside causing the effective size to be less. So hooking up any washer to less than 2" older piping is a risk, you just don't know. To combat this, discharging into an adjacent utility tub solves it. Also in Europe, becoming more available in the U.S., are combo washer/condensing dryers that do not discharge at the fast rate.

Is the 2” ”requirement” for the HE top loaders as well? They use significantly less water than regular top loaders.

Good question. I can see I have some research to do lol

We have an older home. The drain had problems handling the discharge water from our old top loader. Over the lasr 20 years we replaced with a front loader and then a top loading HE without having that problem.

As was noted - 2" is code and it's all the way back to the main stack. That said, there are a ton of new washing machines discharging into 1-1/2" pipes.

I don't think code cares about the style of washing machine - because it could just as easily be swapped out with a top loader later. That said, the actual problem of potentially discharging water faster than a 1-1/2" drain can handle is completely solved by a front loader. They simply don't use that much water per fill. If you can fit one in your setup, the problem is solved.

The truth is that you will probably be fine with a 1-1/2" drain line as long as it stays clean and isn't restricted galvanized or full of lint. If you do run into a problem, reduce the outlet of the washer drain hose -just a little bit (reduce it from 1-1/4" to 1" for example). It will slow down the discharge rate enough to keep it from overflowing.

Hi, Do you have room for a deep sink?

Good luck

Woodbutcher

Unfortunately no. W/d are slid in between two walls

Just buy your new washer - since a front loader doesn't seem to be an option. Reduce the size of the outlet pipe a little bit if it overflows.

I would never restrict the discharge hose on the washer. I'd bet your appliance instructions might even say not to (a la G.E.), and would void warranty. The pump is sized for a rate of flow, and backpressure can damage/reduce longevity of the pump.

Also, High Efficiency washers aren't guaranteed to have a smaller gpm pump, but certainly there is less water to evacuate.

As I said earlier, it is a risk, especially if you don't know the condition of the house pipes. I don't think you can calculate the effective gpm/inside diameter of pipe, as it will also depend on the water level and the rate it enters the pump from the spin/drain cycle.

Or run it into a deep sink.

Hi Kim, same vintage house and drain pipe size here. What did you end up doing?