Richard H Weymouth , MA December 12, 2016 Appliance: Model ? Boiler coil I unscrew back plate. ( unplug) it first. Pull the two power and unplug heat sensor. In side unscrew all the screws ( back ones first). Reverse to put back together. Read More... Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes Tools: Screwdrivers