Specials FREE Thermostat Get a Free thermostat with the purchase of a Trane High furnace or a full system install. Relay panels have an additional cost. Efficiency Upgrades Every 95% furnace (S9V2) installation gets a $350 Serenity Air instant rebate, on a 16 SEER or above HP. Need HVAC Service? Contact the experts at Serenity Air. Call us at 253-255-5682! Request Service