Zanussi Washing Machine drain problems

[pewe]

Cleaned out the drain pipe, filter and waste pipe after complaints by the family of skin irritation. Also ran washing machine cleaner through on 90degree washes a number of times. Pump seems to be working OK and draining in a reasonable time.
They are still complaining that there is minor irritation and there is a smell when opening the door after being shut overnight.
As far as we know the powder etc. is still the same.
Can anyone suggest further action?
Is there a commercial strength cleaner we can try?
Thanks in anticipation, Pewe.

 

[Jakes]

Hi, If the drain pipe is connected to the sink waste its possible that the machine is back filling with dirty water from the sink. That would explain the smell. This can be fixed by moving the drain pipe so it rises as close to the worktop as possible and then down into the sink waste spout.

As far as skin iritation goes, I would say thats a separate problem. I would try non-biological powder tablets for a few weeks. Non-bio removes the chance of the bio agents effecting the skin and tablets makes sure you are not using to much powder. If it doesn't solve the problem then its not the powder. If it does then you go back to bio but use less.

Are you using a brand powder?

 

[pewe]

Thanks for the reply Jakes.
The wastepipe is actually a dedicated one off the main sewer downpipe but hasn't proved a problem previously in terms of smell. It has a trap between the sewer pipe and the washing machine so is unlikely to be siphoning.
Also the powder hasn't changes as far as I'm aware.
Having cleaned out the trap and machine drain pipe is there anything else to clean? As I said in my first post the machine filter is clean.
Cheers, Pewe.