During the peak of a heating season, a client had an issue with one of their institutional buildings – the Water Source Heat Pumps (WSHPs) that were supposed to provide supplemental heating were cooling the spaces! The client initially thought the Heat Exchanger (HX) serving the system was corroded and blocked and received bids for replacing the HX. Before proceeding with this work, the client asked BEC to review the issue. BEC performed functional testing on the system and discovered that an actuator that operates a crucial valve had failed. In the failed position, the water from the building WSHPs were flowing to the cooling towers instead of the boiler HX; I.E. it was stuck in cooling mode instead of heating the building. BEC was able to manually operate the valve, allowing water to flow through the HX and allowing the WSHPs to provide the much-needed supplemental heating. BEC commissioning tests confirmed that the corrective measure was to repair the actuator. BEC correctly diagnosed the problem and saved the client from spending considerably more (10-20X the cost of the simple actuator repair) on a HX replacement that would not have solved the problem.