The Calmag CalCombi Mini (SI-CALCOMBI-MINI) is a space-saving, dual-purpose in-line scale inhibitor that combines magnetic and electrolytic scale prevention technology in a single 105mm push-fit unit. It can be fitted to a central heating system to help prevent corrosion, or to a cold water main to prevent limescale forming, and is supplied complete with 22mm push-fit fittings and 15mm push-fit stem adaptors, making one unit suitable for both pipe sizes.
Inside the nickel-plated copper body, a magnetic bar induces a single polarity into the water so that calcium and magnesium particles repel one another rather than crystallising into hard scale, while a set of zinc plates reinforce this effect electrolytically and gradually release zinc into the supply to combat corrosion from dissolved oxygen. The unit carries a lifetime guarantee and requires no power, chemicals or ongoing maintenance.
12 Bar
Max. Working Pressure
20 Bar
Pressure Tested To
Two Technologies, One Unit
The CalCombi Mini combines a magnetic bar and zinc electrolytic plates in a single housing — giving both scale-crystal disruption and corrosion protection from one compact, maintenance-free fitting.
Installation Requirements
An earth bonding wire must be fitted as part of installation. The unit should be installed no less than 1 metre from the appliance being protected, and secured with brackets either side to limit pipework movement. Collet clips (supplied) should be fitted after installation as added security against pipe disconnection.
Combined Magnetic & Electrolytic Action
A magnetic bar induces single polarity into dissolved calcium and magnesium ions so they repel rather than crystallise, while zinc plates reinforce the same effect electrolytically as water passes over the inner copper body.
Corrosion Protection
Zinc plates gradually disperse small particles of zinc into the water supply, helping to combat dissolved oxygen and reduce corrosion within the system — making the unit suitable for both hot and cold water applications.
Space-Saving Mini Format
At just 105mm long, the Mini format suits installations where space around pipework is restricted, while retaining the same internal technology as the full-size 160mm CalCombi.
Speedfit Push-Fit Installation
Supplied with 22mm push-fit fittings and 15mm stem adaptors for fast, tool-light installation without soldering, suited to both new-build and retrofit work.
One Model, Whole-House Protection
A single CalCombi Mini suits 15mm, 22mm and 28mm pipework via its adaptor kit, giving whole-house scale and corrosion protection from one product line.
No Power, No Chemicals, No Maintenance
The unit is entirely passive — no electrical supply, batteries, salt or chemical dosing are required, and it carries a lifetime guarantee against manufacturing defects.
Technical Specification
| Product Code |
SI-CALCOMBI-MINI |
| Length (this Mini variant) |
105mm |
| Length (standard variant, for reference) |
160mm |
| Diameter |
32mm |
| Material / Finish |
Nickel-plated copper |
| Connections |
22mm push-fit, with 15mm push-fit stem adaptors supplied |
| Maximum Working Pressure |
12 bar (168 psi) |
| Pressure Tested To |
20 bar (280 psi) |
| Maximum Temperature |
70°C |
| Maximum Flow Rate |
1.08 l/sec (14 gpm) |
| Guarantee |
Lifetime guarantee against manufacturing defects |
| Approvals |
WRAS approved |
Typical Applications
- Combination boilers
- Showers and water heaters
- Immersion heaters and thermal store boilers
- Hot water cylinders
- Washing machines and dishwashers
- Central heating systems (as a limescale or corrosion inhibitor)
Frequently Asked Questions
What is the difference between the CalCombi and the CalCombi Mini?
Both share the same internal magnetic and electrolytic technology, connections and pressure/temperature ratings. The difference is physical length: the standard CalCombi is 160mm, while the Mini (this product) is 105mm for use where space around the pipework is limited.
Does it soften the water or remove minerals?
No. Scale inhibitors do not change water hardness. The CalCombi Mini reduces the ability of dissolved minerals to form hard scale as heated water passes through the system, rather than removing them from the water.
Can it be fitted to both hot and cold water pipework?
Yes. It is a dual-purpose unit that can be fitted to a central heating system to help prevent corrosion, or to a cold water main to prevent limescale forming.
What fittings are included?
The unit is supplied with fixed 22mm push-fit connections and two 15mm push-fit stem adaptors, so one product covers both 15mm and 22mm pipe runs.
Is an earth bond required?
Yes — an earth bonding wire must be fitted as part of a compliant installation.
Will it stop scale forming in a kettle?
Not entirely. The CalCombi relies on water flow through the unit to prevent scale formation; since there is no flow inside a kettle, soft scale can still form there. Any scale that does form in a kettle after installation will be soft and easy to brush away.
