Fernox F1 is suiable for use with Softened Water, says the HHIC

News has hit the grapevine than the inhibitor F1, made by Fernox, a market leader in water treatment chemicals, can be used with softened water.
In general, we shouldn't trust rumours, but the public release of the information has come strieght from the horses mouth -

we received a PDF press release, originally from fernox explaining the details a little bit. The technical bulletin states:

"In January 2013, the water treatment group of HHIC approved the following statement concerning the use of water softeners: 




Where a water softener is present in the dwelling ensure that a heating system primary circuit is filled with mains water via the general bypass valve as required within BS14173. Note: A water 

softener must comply with BS14173 (this states that there must be ‘a general bypass valve which 

enables the softening unit to be isolated from the mains, while maintaining water supply to the 

end user’. For installation requirements, refer to WRAS Information and guidance Note No 9-07-

01 “Information for the installation of ion exchange water softeners for systems supplying water 

for domestic purposes”. 

Refer to boiler manufacturer’s instructions for any additional advice on softened water."

Consequently any future central heating installation where a water softener is present should not be filled with softened water.

The DWTA support this advice, however there will still be some existing installations where the primary circuit has already been filled with softened water. For these installations, the following advice is still relevant.

When a central heating system is filled with base exchanged softened water, Fernox Protector F1 will adequately protect the heating system as long as it is correctly dosed and maintained t

throughout the life of the system. The correct dose rate of Fernox Protector F1 can be verified 

using either a Protector Test Kit or a Fernox System Health Check, both available from plumbing 

merchants.

This recommendation is identical to that given for natural waters and indicates that Fernox Protector F1 inhibits in all water conditions."

Softened Water has been proven to NOT cause corrosion in aluminium heat exchangers

Report released in Woking, December 2012.

Since the 1980s, there has been disagreement within the professional water heating sector about the use of softened water in central heating systems with aluminium heat exchangers. The water softener manufacturers say that you can use softened water, while some of the chemical inhibitor manufacturers say you cannot.

To settle the argument, in March 2012 Harvey Water Softeners got together with other members of the UKWTA (United Kingdom Water Treatment Association) and commissioned BSI (British Standards Institute) to carry out a test and prove, once and for all, who was correct.

The results were announced by Harvey Bowden, the Chairman of Harvey Water Softeners, at the HHIC Annual Conference during the parliamentary reception at the House of Commons on Wednesday 28th November 2012.

The report states that, “Over the lifetime of a modern central heating system, filling with base-exchange softened hard mains water would appear to present no significantly greater risk of corrosion of system metals than filling with hard mains water”.

So one question remains : why there was confusion in the first place... was there another source of corrosion not accused? - further updates coming soon.

Harvey is a trusted brand of water softeners and has spent many years perfecting the brand - a trusted seller of Harvey equipment is Spectrum Softeners.