The Sentinel X400 Sludge Remover (MPN X400) is a high-performance, non-acid cleaner specifically designed for cleaning older central heating systems. It restores circulation to radiators and pipework by lifting and dispersing built-up magnetite sludge, eliminating cold spots and restoring proper heat distribution. X400 is ideal where a new boiler or pump is being fitted to an existing system, or where radiators have cold areas caused by sludge build-up.
1% of System Volume
Dose Rate
Up to 10 Radiators
Coverage
Up to 3 Weeks
Suspension Time
Dosage
1 litre of Sentinel X400 treats a typical domestic system of 8 to 10 radiator panels. Larger systems should be dosed with 2 litres, at a rate of 1% of system volume.
Circulation Requirements
To clean an existing system in accordance with BS 7593, X400 should be circulated at normal operating temperature, with all valves open and the pump on maximum flow, for a minimum of 2 hours or until satisfactory performance is restored. Where systems are badly fouled, a longer circulation period of approximately 3-4 weeks is recommended, and this product will not clear a completely blocked pipe.
Powerflushing Compatible
For faster, more effective cleaning, X400 can be used in conjunction with a powerflushing device. The product is not aggressive and can be safely left circulating in the system for extended periods where needed.
Removes Built-Up Magnetite Sludge
Formulated with a ruthlessly efficient formula that shifts built-up magnetite sludge from radiators and pipework, addressing the leading cause of cold spots in older systems.
Restores Even Heat Distribution
By clearing sludge from circulation, X400 helps restore a more even heat distribution throughout the property, improving comfort and reducing energy waste.
Non-Acid, Non-Aggressive Formula
Unlike acid-based treatments, X400 has a non-acid formulation which does not cause pin-holing or leaks, making it safe for extended circulation periods.
Holds Sludge in Suspension
Once mobilised, the product holds sludge in suspension for up to 3 weeks, which is particularly useful for pre-dosing before a scheduled flush or powerflush visit.
Prepares System for New Components
Ideal preparation before fitting a new boiler or pump to an existing system, helping to prolong the effective life of the new component by removing damaging debris first.
Suitable for Aluminium Systems
A non-acid formulation suitable for use in all types of indirect heating systems, including those containing aluminium components.
| Product Identity |
| Manufacturer |
Sentinel (Sentinel Performance Solutions) |
| Product Name |
Sentinel X400 Sludge Remover (High Performance Cleaner) |
| MPN |
X400 |
| Dosage |
| Dose Rate |
1% of system volume |
| Standard Treatment |
1 litre per 8-10 radiator domestic system |
| Larger Systems |
2 litres |
| Circulation & Application |
| Minimum Circulation Time |
2 hours at normal operating temperature, maximum flow |
| Heavily Fouled Systems |
Extended circulation up to 3-4 weeks |
| Sludge Suspension Time |
Up to 3 weeks |
| Powerflush Compatible |
Yes |
| Compatibility & Compliance |
| System Types |
All types of indirect heating system, including aluminium |
| Standard Referenced |
BS 7593 |
| Next Step |
Drain, flush, then treat with Sentinel X100 Inhibitor or Sentinel X500 Inhibited Antifreeze |
What is X400 designed to remove?
It is designed to remove built-up magnetite sludge from older central heating systems, restoring circulation to radiators and pipework and eliminating cold spots.
How long should I circulate X400?
For a minimum of 2 hours at normal operating temperature with all valves open and the pump at maximum flow, or until satisfactory performance is restored.
What if my system is very badly fouled?
For heavily fouled systems, a longer circulation period of approximately 3-4 weeks is recommended, and using a powerflushing device will speed up the process.
How much X400 do I need?
1 litre treats a typical domestic system of 8 to 10 radiators. Larger systems should be dosed with 2 litres.
Will X400 clear a completely blocked pipe?
No. This product will not clear a completely blocked pipe - it is intended for circulating sludge and debris, not resolving total blockages.
What should I do after using X400?
Drain and thoroughly flush the system, then refill and treat with Sentinel X100 Inhibitor or Sentinel X500 Inhibited Antifreeze.
