Boiler filter and softened water?

[leegsi]

We are about to have our combi boiler replaced along with fitting a water softener (The salt type).

Can the softened water be used to fill the boiler (Reduce lime scale etc) and what inline filters do people recommend for combi boilers?

We live in a very hard water area so want to protect and prolong the heating and water system as long as possible.

 

[Swwils]

First of all you could aim to reduce flow rate in the system.

Secondly, it probably wouldn't be advised to use the softener. If really needed you can have your plumber introduce the required treated water into the sealed system, with something like a pureotap and go to VDI standards if the boiler manufacturer allows (most in the UK do not and require chemical inhibitor).

Not many plumbers will even know about this at all.

 

[muggles]

It depends on the manufacturer, ultimately. Some allow softened water, some even encourage it, but others say absolutely not

 

[JohnD]

ah, if only some sort of scientific tests had been carried out. with a report we could all read, to see what the results of softened water were.

 

[JohnD]

but wait!

The British Standards Institute corrosion report dated 12th December 2012!

 

[JohnD]

well, bless my soul.

who'd have thought it.

"The British Standards Institute corrosion report dated 12th December 2012, shows that in the long term softened water has no adverse effect on aluminium heat exchangers.


This myth stems from an outdated British Standard BS7593:1992. This standard was revised in 2006 which now includes that softened water can be used providing a suitable chemical inhibitor is used. It appears that some boiler manufacturers still base some of there concerns around this confusion, and the 1992 version. The main corrosion inhibitors, such as Fernox and Sentinel, for years have not had a need to change or consider softened water in their formulations. Consequently it has been easier to say nothing.


But, now Fernox have released a technical bulletin (number 21) which includes the following extract:


“Fernox technical bulletin 21: 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 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.”


Sentinel has a similar statement:


“Sentinel X100, the benchmark of quality inhibitors treatments, was specially formulated to be able to control corrosion and inhibit scale formation in fill-water of any quality, including base-exchange softened water. Applying and maintaining the correct dose of X100 will protect your system, ensuring it remains quiet, reliable, effective and energy-efficient for its entire service life.”

 

[TeaAndBiscuits]

If you're bothered you can just set the softener to bypass when you fill/top up the CH system. That's what I do with mine even though it's unnecessary.

 

[leegsi]

Thanks for the info

 

[sxturbo]

My system is filled with softened water, no inhibitors have been installed,

This is very common on the continent, in Germany I believe it is a regulation.

Install an spirotech air seperator aswell, all will be well.

Needs a decent installer though who knows what their doing and has the necessary kit to test the pH of the water.