New washing machine----but pipe is 1.5 inches

[MattF]

Hello,

Just a question regarding the code as it pertains to the drain of a washing machine.

My house is about 12 years old, and the standpipe/drain line for the washing machine is 1.5". I believe the code now calls for 2" pipe, due to the fast drainage of new washing machines. However, I would like to purchase a new washing machine--does this mean all the pipe will have to be replaced with 2" right to the 4" main drain line? It would involve significant removal of drywall, etc. Am I taking the chance of an overflow if I leave it?

Forgive my ignorance with this....I'm no plumber as you can tell.

Any information would be appreciated. Thanks.

 

[Geofd]

Yes all the way back to the bigger main (2").

 

[BlueSkyHigh]

Interesting conundrum. Has the water outlet drain on these new, fast-draining washing machines also been increased in size accordingly or has the outlet pressure from the drain pump been increased to fire hose levels?

 

[MattF]

Yes all the way back to the bigger main (2").

Hmmm.....that's the answer I was afraid of. Thanks for the reply. I appreciate it.

 

[MattF]

Interesting conundrum. Has the water outlet drain on these new, fast-draining washing machines also been increased in size accordingly or has the outlet pressure from the drain pump been increased to fire hose levels?

Good question. The outlet drain on these washers seems to be the same size....so my guess is they are just equipped with more powerful pumps. I find it hard to believe that everyone who has bought a new washing machine in an older home has updated the entire plumbing system.

 

[Twowaxhack]

I connect new washing machines to old plumbing on a regular basis.

It works if the drain is clean.

Facts……

 

[Geofd]

Yeh in mass they changed the code has to be 2"

 

[TomFOhio]

The last time I changed piping for a washer they made me run 3" from the main and right where it turns up to
go in the wall i reduced it to 2" all the way up.

 

[Geofd]

I think that's even a better way!!!!!!

 

[Riickk]

They may have changed the plumbing code, but the change is for properties built, and pipes installed, AFTER the date the code changed.
Homes built before the change are still code-legal - grandfathered.
Otherwise when they mandated all electrical outlets had to have a receptacle with openings for 3-prong plugs, every house built in say 1950-1960 would need new receptacles. Ditto for 3-dozen other things.

 

[MrInfoPhilly]

Typically existing size plumbing is grandfathered in. But a renovation youd have to install new work up to current code.

It should work fine as is