Siemens Lady 45 Dishwasher - Starup and Wat...

We have been experiencing following problem from last 6 months

- Once in a while dishwasher does not take water after switching on.
- Then it automatically starts taking water after 2-3 days
- It has a Aquastopper, which does not ge activated when this problem arises
- After running 4-5 rounds of washing. next time it again stops working.
- cant figure out whats the problem.
- Many times when we found that machine is not taking water, the salt level had gone low. So we fill up the salt but it still doesnt start immediately.
- it only starts after few days or so.
- also tryin cleaning aquastop filter.
- i also dont seee any reset knob on machine for overflow of water etc.