Fernox 56600 500ml F3 Cleaner

I only ever use this product

This was really cheap as was supposed to be used/damaged. A couple of dents on the package only.Put it in the system through a towel radiator. 4 hours circulating & every radiator is much hotter to touch, rooms are much warmer.Going to leave in a couple of days, as can be left in for a week. Will then drain, refill & flush the system before adding Fernox Inhibitor.Brilliant cleaner & easy to dose.

Dose what it says just what I needed

I purchased this because I was having some problems with my hot water system and wanted to give it a good flush to start with to ensure the problem was not a simple blockage.I know Fernox to be a good trusted brand and with the price on amazon I could not find it a lower price anywhere else so I purchased some.First I completely emptied the total system and gave the header tank a good clean the as the system refilled I added the cleaner, I only used 1 bottle although I have a 10 large radiators in the house I had not used the product before and so thought 1 bottle to give it go would be best to start with. Once the system was full again and all the rads bleed I turned the boiler on and ran the heating and hot water for 2 hours, then ran it again later in the day and again the next day. then I emptied the system again and wow the water coming out was very black and so I know something had happened. I refilled the system and ran it again, did this one more to give it a good flush and on the last fill I added some Fernox protector.Since I have done this the system has worked fine (the old problem was the boiler kept cutting out from over heating) the boiler even sounds quieter, now I can say this will fix all problems but it certainly fixed my issue and saved me a small fortune from getting a plumber involved. I now plan to use the cleaner once a year and give the complete system and good clean.

Put it in the system a year ago and rads are still clean

It gets rid of magnetite build up at back of boiler (gravity system). Should be standard issue by your boiler supplier as Part of a regular maintenance regime, saves getting a new boiler anyway (diagnose with a magnet) v easy to apply.

I poured the contents into the feed tank and left it for nearly 2 weeks (as per instructions) and had the central heat on periodically. It made my boiler run a bit smoother, but it did not get ridged of the all the rusty / dirt in the radiators. I also noticed that it gives off this toxic type fumes, even after i had flushed the system several times.

Brilliant product, we now have several radiators working seamlessly that were blocked for years. Also, Fernox provide speedy and extremely invaluable customer service on your inidividual situation. For us, Fernox F3 was used to clean a solid fuel system that hadn't been cleaned for 25 years, comprising 10 radiators, several double. They advised 2 bottles to be placed in the header tank to remain in the system for up to 2 weeks, followed by 3 flushes out, then 2 bottles of Fernox F1 to keep the system in good working order, which then stays in the system. (These are double the amounts a cleaner/smaller system would have required). It is important to clean out your header tank before you begin (and keep it clean in the future) as you don't want additional gunge going round your system. Flushing out after Fernox F3 is time consuming - we left the pump on, with the water running into the header tank, as we let the water flow through a radiator drain at the system's lowest point, attaching a hosepipe running to our main drain, for approximately 2 hours on 3 consecutive days. Make sure the water isn't draining out faster than the water going into the header tank, as in that way, there will less trapped air. Very doable as a DIY task and avoiding the expense of powerflushing.