Fernox 56599 F1 500 ml Central Heating Protector by Fernox

Used Fernox inhibitor previously and this time cleaned central heating system with a double dose of Fernox F3 and refilled with Fernox F1. It provides peace of mind that the pipework remains in good condition for many more winters.

Following our Vaillant boiler service, the ph was still too high even though I had added an alternative brand enough to treat 400 lts a few months before which had really quietened both the boiler and the pump right down. The engineer strongly suggested using Fernox F1 enough to treat 130lts which is a 500ml bottle which was £20 on Amazon provided you look carefully through the purchase options.I have used Fernox over many many years, but this time round I purchased on price as I got 2 alternatives which did 400lts for the same price as the Fernox for 130lts. The next service will see if there is a difference. I suspect there will be when Fernox lives up to its pedigree.

Use it every year, works for us.

Works well but it is never quite as good as you expect. I still have a leak after using 2 bottles. Will have to order another bottle.

Arrived promptly and was as described