washing machine waste, is this right?

[diy_fun_uk]

i'm not quite sure why it's been plumbed this way (unless there's a valid reason?) but to me there's no need to have the split level of horizontal pipework i.e. section leading horizontally from the u bend into an angled joiner and 'up' to another section of horizontal pipework. this config is causing water to sit in the lower section.

what i want to do is rip out all the existing stuff (vertical waste pipe, u bend, lower horizontal pipe and angled joiner), fit a new section of horizontal pipe at the same (higher) height of the existing pipework and then use a washing machine kit like this, then no water would stand in a lower section. any reason why i shouldn't do this? i also feel the vertical section could do with being a bit longer, correct?

 

[Newboy]

You plan is correct - there should be a constant fall from the outlet of the standpipe to the main waste.

The standpipe height looks OK but a little higher won't do any harm.

 

[diy_fun_uk]

Thanks for reply, thought it didn't look right!