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Can you use softened water in your boiler?

I have just had a call from a potential customer in Bishop’s Stortford, that I went to see the other day. He had a quick chat with one of his neighbours to say that he was thinking about having a softener installed.  His neighbour told him that he had been told by the developers of the new site, that he couldn’t have a softener installed because it will damage his boiler.
This is the latest information that is not wildly know but we are trying to change peoples attitudes.
“Is it ok to use softened water in a boiler?”
This is a question we are regularly asked by customers and installers alike.
Advice has changed over the years, and separating fact from fiction can be difficult without some expertise in the subject. 
The simple answer is yes, it is perfectly acceptable to use softened water in your boiler as long as you observe the following advice from the Heating and Hot Water Council (HHIC):
“Where a water softener is present in the dwelling, ensure that the heating system primary circuit is filled with mains water via the general bypass valve as required in BS 14743.”
Note: A water softener installation must comply with BS 14743 (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”.
Put simply, using a water softener is fine as long as you fill your central heating (radiators) with unsoftened water. A reputable installer (ourselves included) will always fit a general bypass valve which makes this process easy.
Prior to the introduction of aluminium heat exchangers during the late 1980’s, it was considered normal practice to fill the central heating system with softened water whenever a water softener was present in the household.
Up to that date, the central heating chemical inhibitors were designed for use with hard water and the combination of an aluminium heat exchanger and chemical inhibitor led to some corrosion problems. It was therefore put into the 1992 BSI standard for water treatment (BS7593:1992) that softened water should not be used where there is an aluminium heat exchanger.
This led to considerable confusion as many installers and householders did not know whether or not the boiler contained an aluminium heat exchanger, so to play it safe, most people recommended that the heating system is filled with hard water.
Matt Ager

By Matt Ager

Joint owner of the business with his brother Ben, Matt looks after the sales and marketing side of things. Working for the family business for the last 30 years since the age of 16, Matt has a wealth of knowledge he can draw on. With his passion for the industry, he can share the benefits of softened water with clients old and new.

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