Citric acid is often using for canning as well as bath bombs, so it’s fair to say its usages are rather varied! The prices of installing a combi boiler are as follows. Call us on or alternatively use the form below and we will call you back! Very good service throughout both technicians were fantastic! we would happily recommend halsalls to friends and family thank you! Thank you for the clear and practical advice it’s saved me stress, time and money!.