Letting out water under pressure, before flushing Fernox filter

[Lucky Luke]

Hi Experts. Though, in past months, I have flushed our Fernox magnetic filter with no particular cause for alarm (I'm always a bit nervous of anything to do with central heating, boilers and so on), today was a bit different. The only different circumstance today from earlier occasions, was that today, I was aware that the radiators were hot, whereas previously, I think it was a time of day when they would not have been heated up (because of the timing setup).

Anyway, today, the radiators were being heated at the time I intended to flush the filter. First, I turned off the boiler, totally. Then I closed the two red taps, so as to isolate the filter. The next thing was to open the little metal screw (a kind of pressure-release screw) to let out the water that had been put under pressure inside the filter. On past occasions when this was done, there was a kind of arc of spurting water, which lasted for perhaps five seconds or so before the arc collapsed. When it did this, I knew it was safe to unscrew the large plastic cap of the filter.

However, today, the water just kept on spurting out. After waiting (for too long, it seemed), I thought it would never stop, so, thinking that there was no other option, I unscrewed the plastic cap anyway, and took out the filter.

After flushing the filter, I replaced it and then screwed the plastic cap back on. The water started jetting out again, so quickly, I opened the two red taps. Then, after a couple of seconds (during which, the water continued to spurt), I closed the little metal screw.

After that, I turned on the boiler and injected some water into the system, until the display seemed OK.

Everything seemed OK when I left the boiler. However, the continually-jetting water referred to above has made me quite anxious. I should hate to do something harmful to the system, just for the sake of not enquiring.

So, my question is: Today, why did the water continue to jet out and not cease, as before? Another question is: will everything now be as it ought to be?

My thanks to anyone that can comment usefully on the above concern and that, hopefully, can answer my questions.
A.W.

 

[muggles]

It sounds like the cr@p valves on your cr@p filter have given up and aren't stopping the flow from the heating system any more. It won't do any direct damage to the system, it'll just become increasingly inconvenient, although continually flushing your filter and topping up the water will dilute the corrosion inhibitor present in the system, leading to increased corrosion. It should really only need doing annually as part of your boiler service

 

[Lucky Luke]

It sounds like the cr@p valves on your cr@p filter have given up and aren't stopping the flow from the heating system any more. It won't do any direct damage to the system, it'll just become increasingly inconvenient, although continually flushing your filter and topping up the water will dilute the corrosion inhibitor present in the system, leading to increased corrosion. It should really only need doing annually as part of your boiler service

Thanks, Andrew. Being inexperienced, I never would have thought that the taps/valves could fail. When the boiler is serviced next summer, I will have this attended to. This information is very much appreciated. Just one more thing, though. You refer to the cr@p valves on my cr@p filter (actually, the red taps are on the feed and exit pipes from the filter). This sounds derogatory, though I could be mistaken, I suppose. Are you implying that Fernox filters are no good, or do you mean that they are now old and ready to be replaced? They are only four years old. Please clarify. Thanks again.

 

[Madrab]

Unless your system is new and you have been advised by the engineer that the filter needs to be cleaned regularly then it should really be left till service time. @muggles is just explaining about what we find all the time with these types of 1/4 turn ISO valves and that they are not very good if used regularly - same thing happens with the boilers flow and return valves too.
They tend to leak after a while as they are going through heat cycles all the time and the nylon seals eventually passes. You need to ensure that the taps are fully at 90 degrees to the pipe, some of them have a final small resistance to overcome before they 'click' fully off.

 

[dreadnoughtheating]

TF1 filters are IMHO Carp.... Alongside the boxes on the shelf, they also stock replacement seals. That tells me plenty. I have replaced them at less than 2 years old for the same reasons the OP has mentioned.

Time will tell if the Fernox replacement (all metal?) one are any better.

 

[Madrab]

Time will tell if the Fernox replacement (all metal?) one are any better.

Yeah strange, they all poo poo'd the all brass spirotech but now they're starting to copy the all metal setup with removable magnet and bottom drain so there's no need to remove anything plastic (that I never did trust),no big seals to replace and no real need for ISO valves as the filter doesn't need removed, just a valve and drain at the bottom which ST have been using for ages.

The MB3 is a well designed bit of kit IMO.

 

[dilalio]

I've fitted a few of the TF1 Omegas and I like them. Nice bit of kit and cheaper than a MagnaClean from plumcenter - with the valves and a dosing kit... about £85.

 

[dilalio]

And the magnet is in a dry pocket so to clean the filter out you close both valves, remove the magnet and open the drain at the bottom of the unit; then open the flow valve to the filter which flushes the magnetite and sludge into a recepticle under the drain valve. The body can be rotated on the slew ring to facilitate this.