I'm trying to create a validation rule formula in Salesforce, that uses two picklist fields. If the first has any value selected, the Second picklist can NOT have any value selected. So basically if Picklist "Boiler_Type_Manual__c" is NOT Null and Picklist "Furnace_Type__c" is also NOT null, a validation rule appears: Cannot have both Boiler and Furnace Type selected!
Any help would be greatly appreicated.