Bell & Gossett 109429 Electric Pump Controller Z-4B

Z-4B Four-Zone Pump Control with boiler reset, for hydronic systems. 120V, 24VA thermostat current. This model features pre-wired integral boiler reset controller. The controller cycles the burner to maintain the optimum system supply temperature relative to the outdoor air temperature. 24 VA transformer and 20 amp rating with quick-connect terminals. 13.5″wide x 8.25″high x 3.25″ deep.