Bosch EXXCEL 1400 Express

Our washing machine appears to be working OK but smells badly when door is opened - have checked filter and pump drain - any suggestions?

What sort of smell? Difficult to diagnose anything without knowing details!

If its a "drain" type smell stick it on the hottest wash with a small amount of detergent - lots of low temperature washes tends to leave a residue of detergent/muck/sludge in sump etc - a real hot wash will loosen this up. Also, if you're in a hard water area, a wash with a descaler agent will help.

Rather than detergent, use washing soda crystals. If you do this on a periodic basis then it will tend to keep your machine free from the muck that tends to accumulate (and smells).