Does the water board charge when checking for leaks?

My water pressure appears to be low, I have a combi-boiler and it wont stay on whilst my shower is being used (which results in very quick showers!) Ive had a boiler specialist look at my boiler and he says its fine, so he suggested I contact the water board to check for leaks? Can anyone tell me if I'll be charged for this? (Dont know if this is relevant, but its Severn Trent Water Im dealing with) Many thanks.