Firstly, i booked 4 nights separately.
When i checked in i was very tired.
Given room 309, right away noticed unpleasant smell, being tired i didn't complain.
After a shower the smell was very bad. Coming from the drains. Musty sewage smell.
Too tired to complain or move rooms i promptly fell asleep. When i woke was feeling quite ill with a headache.
As i had 3 more nights booked i requested a room that doesn't smell.
I was shown room 209 and 504. Both rooms were fine without horrendous smell.
Im now staying in room 504.
In the bathroom there is some smell but its acceptable, no comparison to room 309.
Difficult to rate this as overall the rooms are well appointed and clean.
I will inquire at reception tomorrow why i was put in a room that has a serious issue with obvious noxious smell. As there were other rooms available that are ok.
Its quite common in Thailand builders dont install septic traps in the plumbing which prevents septic tank fumes back into the rooms.
***Advice for the owner, manager make sure to rectify this issue. Its a health hazard.***