Boiler controls and boiler control systems

Updated: May 10, 2026.

This page is maintained for the Global English Spirax Sarco product catalogue and is intended as a product-family selection guide for boiler house buyers. For application-specific sizing, control philosophy, compliance review or model-level documentation, continue into the linked product pages or contact the Spirax Sarco team.

Quick answer: Boiler controls and systems combine the monitoring, control and support hardware used to keep boiler water level, dissolved solids, feedwater condition and blowdown discharge under control across the boiler house.

Boiler house priority	Best route	Why it matters
Water level protection and feedwater control	Level controls	Helps manage low-water risk, high-level alarms and stable boiler water level control.
Boiler water concentration and continuous blowdown	TDS blowdown controls and conductivity meters	Supports steam quality, reduces unnecessary blowdown and gives clearer visibility of boiler water condition.
Sludge removal and safer blowdown discharge	Bottom blowdown systems, blowdown vessels and vent heads	Improves solids removal and helps handle hot blowdown water and flash steam more safely.
Feedwater conditioning and deaeration	Feedtanks and steam injectors	Helps mix make-up water and condensate, release dissolved gases and prepare feedwater before it reaches the boiler.
Heat recovery from blowdown and flash steam	Heat recovery systems	Reduces wasted heat, lowers make-up water demand and improves the energy performance of the boiler house.
Representative boiler water testing	Sample coolers	Supports safer sampling and better decisions on water treatment and control settings.

What are boiler controls and systems?

Boiler controls and systems are the instruments, valves and support packages used to monitor water level, control blowdown, manage feedwater condition, recover heat and improve safety around steam generation.

When should you use TDS blowdown control?

Use TDS blowdown control when steam generation is increasing dissolved solids in boiler water and you need to keep TDS within the target range without wasting more water and heat than necessary. Compare the dedicated TDS blowdown controls range when this is the main concern.

Why is boiler water level control critical?

Boiler water level control matters because low-water conditions, unstable feedwater control and poor alarm handling can affect safety, steam continuity and boiler reliability. Start with level controls when water level is the main operating risk.

What does a boiler feedtank do?

A boiler feedtank acts as an atmospheric deaerator and mixing point for make-up water, returned condensate and flash steam. It helps condition feedwater before it enters the boiler and can reduce dissolved oxygen and avoidable operating cost. See feedtanks for the relevant product family.

How can boiler blowdown heat be recovered?

Boiler blowdown heat can be recovered by separating flash steam, reusing that heat on the feedwater side and reclaiming remaining heat before discharge. Use heat recovery systems when energy loss from blowdown is part of the improvement case.

Boiler-house searches usually split by the operating risk that is causing the most cost or instability. Start with boiler level controls when safe water-level management is the main concern. Move into TDS blowdown controls when unnecessary blowdown, boiler water concentration or steam quality are driving the review.

Use sample coolers when representative water testing is needed alongside control hardware. Review deaerators when feedwater conditioning and oxygen removal are part of the project, and continue into boiler blowdown heat recovery systems when the improvement case depends on reclaiming heat that would otherwise be lost to discharge.