Boiler controls and systems > TDS blowdown controls
BC3250 Boiler Blowdown Controller
The BC3250 is a Spirax Sarco boiler blowdown controller for steam boilers that monitors boiler water TDS and drives blowdown action automatically while also handling bottom blowdown timing, retransmission, trend display and Modbus communications.
Quick facts
BC3250 sits on the model-specific end of the
TDS blowdown controls
route. It is used on steam boilers where dissolved solids must be monitored
continuously and blowdown has to respond more consistently than a manual
routine can provide.
Rather than acting only as a measurement device, BC3250 combines conductivity input, blowdown valve control and bottom blowdown timing in one controller. That makes it a clearer fit for projects already moving from general boiler water quality control into product-level selection.
BC3250 is a good route when the project needs to:
If the immediate need is still the measurement side rather than the control side, continue into boiler water conductivity meters.
The current technical and installation documentation confirms that BC3250 supports:
0/4-20 mA retransmission, RS485 / Modbus RTU and infrared communicationCP10, CP30 or CP32Pt100 temperature input for display and compensationIt is documented for indoor panel, DIN rail or backplate mounting and is used in steam boiler blowdown and contaminated condensate monitoring arrangements.
Before final specification, confirm where the probe will be mounted, whether temperature compensation is needed, how the blowdown valve package will be arranged and whether the site needs data retransmission or Modbus connectivity.
It also helps to confirm whether the wider project includes only continuous TDS control or a broader boiler house upgrade involving boiler controls, heat recovery systems or boiler water management guidance from controlling TDS in boiler water.
The CP30 is a Spirax Sarco conductivity probe for steam boiler TDS monitoring and blowdown control systems. The probe can be cut to the required insertion length and installed in a probe elbow, threaded flange or boiler connection.
The BC3150 is a Spirax Sarco boiler blowdown controller for steam boilers. It uses conductivity probe input to control the blowdown valve and supports Pt100 temperature compensation, 4-20 mA output, infrared communication and pulse blowdown.
BC3250 is usually selected alongside probes, blowdown valves, mounting arrangements and the wider boiler water control strategy.
Return to the wider TDS blowdown controls route when you need to compare BC3250 with the broader boiler water quality control path.
Review conductivity meters when the next step is confirming measurement hardware, probe arrangements or boiler water sampling support.
Use the boiler controls overview when the project also includes level control, heat recovery, vent hardware or wider boiler house upgrades.
