plumbingwashing-machine
My washing machine drain is 7.5 feet from the floor. I plan on researching my washer and making sure it can pump that high. I want to hook it up to a 1.5 inch PVC pipe drain. The 1.5 pipe is above my main sewer drain.
This leaves me with less than a half foot to connect it to the 1.5 drain pipe. How should I do that?
Experience tells me that at least some models of washer won't hold water unless the drain hose extends above the water level of the wash basin. I can't quite figure out what you're trying to say about extending pipes, but it should be safe to have the water drain out of the washer drain hose at its maximum height.
Eventually, the drain hose can be high enough that the water column overwhelms the pump (or hoses), but you'd have to be doing something bordering on insane to reach that. Every foot of height in a water column adds .43 psi of water pressure, so even a hose rising 15 feet above the washing machine will provide less than 7 psi of back pressure. I can't imagine a washing machine pump which doesn't handle that.
No. Well maybe it can, but it shouldn't.
If you check the documentation that came with the washer, it should contain the maximum drain height. Generally, the maximum height is around 39" (99 cm).
Newer washers often have a drain hose permanently attached, which is designed to make drain installation fool proof. The supplied drain hose shows you exactly how high the washer can discharge.
Depending on the machine, and whether or not you're already using a pedestal. You may be able to raise the whole machine up, to accomplish what you want. The maximum height is not height above sea level, it's height above the bottom of the washer. So if it's possible to do so, raising the machine up a few inches (safely) might be the solution.
If it's a front loading washer; and you're not already using a pedestal, you may be able to purchase (or build) a pedestal to raise the machine up. If not, you may want to think about building a raised floor to raise the whole area up.
International Residential Code (IRC) says.
International Residential Code (IRC) 2012
Chapter 27 - Plumbing Fixtures
SECTION P2706 WASTE RECEPTORS
P2706.2 Standpipes. Standpipes shall extend a minimum of 18 inches (457 mm) and a maximum of 42 inches (1067 mm) above the trap weir. Access shall be provided to all standpipe traps and drains for rodding.
Which means if you connect the drain hose to a standpipe, the standpipe has to be at least 18" above the point at which water will begin to flow from the trap. So your 43" height, could quickly become 61".
Best Answer
I would recommend not doing what you suggest, here's why:
A typical rough-in for a clothes washing machine is as show in the picture below and consists of the following:
Your discharge hose will fit inside the 2" pipe opening and will usually enter the pipe about 6" to 8". This connection is not water/air tight.
The size of the p-trap and the vertical section of pipe are to accommodate for the flow rate of the washing machine's discharge. The p-trap will create a restriction to the flow and the vertical pipe allows for some head water to buildup without putting any back pressure on the washing machine's internal pump.
A p-trap is a must as it will prevent sewer gas from entering your house. The vent is required to protect the water seal of the p-trap but can be replaced with an air admittance valve depending on local codes.
I would imagine that if your machine can pump that high it will be near its limit and without any room for a vertical section of pipe to discharge into you will have to make the connection sold which will put additional back pressure on to the machine's pump (even more due to the pipe size only being 1.5") which will shorten the life span of the pump.