this is a question related to the plumbing
system in the heads.
the loop of the discharge pipe runs very high inside a locker in the heads compartment ,almost 90 to 100 cm, I keep having a smelly "water return" rushing back in the bowl, I assumed this is due to either a defective one-way valve in the pump,or maybe the over-raised vent loop.
before I dismantle the pump unit and undertake the replacement of this valve, I wonder if it helps if I lowered the loop first ?? and what would be the recommended height??