We have this problem over a year already 煤氣公司個師傅 came a year ago and also recently to check and said there is nothing more they can do. So I called our stove supplier and here's the options:
1. They can send in their sifu for the repair the sifu inspection is $300 and usually worst case repair bill is about $1000.
2. Replace with a new model (V6022FVV) which combine gas + electricty and will fit in our RC kitchen with no modification the cost is $5800
3. Replace with another better brand of gas stove with steel surface (SRV574X01) which will also fit in RC kitchen with no modification the cost is $4700
You can browse their web site for more information including contact numbers - www.cristal.com.hk