Magnetic filters for heating - do they even work?

My system was drained for a boiler swap, after 18 years of operation. When the water was drained, it was rather clean. Some oil on the surface, but otherwise clear.
Also, it is often forbidden from using additives by the boiler manufacturer. Also, filters are being sold aggressively, but the boiler installation guide doesn't mention them. PEX piping, steel plate radiators, cannot remember last time I had to fill for pressure loss.

Can you recommend a flow meter to check if circulation pumps are working and how fast?

We just had a two-port valve seize up. Turns out it was full of metal shards.

Which is disappointing, because our plumber installed a mag filter a year ago. But it's installed horizontally, and is probably too small.

Guess we'll get a bigger one. And hopefully powerflush the system again before installing it.

Fernox TF1 Compact is a great choice. It comes with spare gaskets. They sell at a fairly high rate, if they were problematic they wouldn't have bought them...I think

Always fit magna clean by a day no comeback

A little perv video... ask a plumber if he likes filters!
Well obviously he DOESN'T like them but... is good for adding chemicals (..really? Only for that filters are good?)
And, by the way, ..U know, these filters will (NOT) protect your (very) dirty system .,, if you Don't Call Him Every 1-2 Years for proper power flush!! Do you undetstand the real ideea?

Did you get THE IDEA, YOU POOR CUSTOMERS?

Our housing association fitted a system filter 10 yrs ago when they installed the boiler with a cracked heat exchanger they still havent repaired the heat exhanger and they have never cleaned out the filter, the closed circuit of the radiators will not maintain pressure for more than 10 mins, the water is literally going up the chimney as steam.

Fitting one is required if wanted the boiler to be guaranteed. I have the Fernox TF1 Omega - nicely made, but there is no top to take off for dosing the system, which is a bit of a pain, but a "FLOMASTA UNIVERSAL FILLING KIT " from Screwfix is a cheap and easy waay around the issue.

You can dose the system via the drain valve in bottom of Fernox TF-1 , need the concentrated aerosol type and the adapter screws onto the thread on drain vent. So no need to ever remove the top of filter.

Have been fitting them since 2005. Originally as said Adey professional. There isolating valves butterfly type were brittle and broke to easy.
Micro 2 from Adey. Neat as long as you don't try and remove canister for a powerflush. Ni on impossible 👎
So have switched to Worcester bosch filters. Solid and easy when powerflushing 😂even though made by Adey.
FenoxTfno longer use as said don't remove lid 👎
Not a fan of any spirotech. Normally have to add valves.
End of the day. Service them every year but if you don't your risk.
Better to have one installed then not.
My opinion systems are better for them than not 👌

Great video. DYIer here... question for you: on a Audley Magnaclean Pro 2 is it a problem if the return pipe first connect to the top entrance and then exit from the bottom one? It would suit my pipes better so I was wondering if I could get away with doing it!

In my experience, nothing collects as much dirt and is as easy to actually remove that dirt as a Magnaclean. Also, I've definitely had Spirotechs that have filled up to the extent of causing flow issues on a boiler, this never happens with a magnclean as the magnet runs out of power before it fills up.

I've found it a bit annoying that the manufacturers have tied extended warranties to a certain filter to be honest, as In my opinion you're now choosing between an extended warranty with an inferior filter, or getting a Magnaclean.

But then as you say, a correctly powerflushed system doesn't really need the filter. Not for the first few years at least, but as time goes on, I do think it's worthwhile being there.

You didn't say if they constrict or reduce water flow, and do you recommend flow or return?

My Dad's radiator valve exploded under pressure because of haemotite and magnetite corrosion. These filters are brilliant.

We install the Spiro combi air separator/magnet dirt trap on the supply side when we use boilers with permanent magnet filters connected to cast iron radiators, steel pipes or steel radiators.

You hit the nail on the head with properly designed, commissioned, and maintained systems not necessarily needing filtration. They should only really be needed for remediation of 'dirty' systems, like you say. However, people generally want a quick-fix, certainly in the domestic space, and coupled with the visual effect from the captured solids, this is what these manufacturers sell on. Good video and I admire your work. Just a tip to watch your terminology - these filters are simply capturing MAGNETIC metallic (not simply "Metallic") particulates, so realistically only iron in this application, but NOT copper or aluminium, to name the two other most common. In poorly commissioned and maintained systems, these elements in solution are bad news, and the effects far worse than those of iron species.

Useless on drop fed systems, domestic circulators don't have enough velocity to remove the particles in the radiators in such a system, only what is held in suspension and can be circulated past the filters.

I like the RadMag it only collects magnetc dirt but thats the type of stuff that tends to block heat exchangers and bypass diverter valves. It cheap and easy to fit if you have a towel rail. It also has a bleed screw at the top.

I installed a magnetic filter (can’t remember the make) in an old system with a new boiler. Despite having flushed the system and added inhibitors, the boiler developed a fault which was traced to a stuck flow sensor. Taking it apart it was obvious debris had jammed the sensor. After the second time it happened, I fitted the filter and never had any more problems. After 6 months I inspected the filter and found a lot of debris in it. After about three bi-annual cleans, very little more debris was found. Never had any more problems.

Do I need a filter on a system that has very little copper pipe work. I installed my system with with plastic coated inside and aluminium (unpornor) for hot water and underfloor heating?

Spirotech MB3 is the best..👍🏻

We moved into our new home 2 1/2 tears ago and the boiler had a Magnaclean filter fitted above it.. There had not been a filter installed on any of our previous heating systems . We had very little detail about previous maintenance so I opened up the Magnaclean filter with ease and found that it had collected a fair quantity of debris, so it had worked well.
As you showed, I also dosed the system via the filter (with Adey MC1) and again it was easy.
No leakage occurred after refitting the cap, so I am quite satisfied with the performance and the ease of use (apart from having to use a step ladder to reach it).

plus some boiler designs they actually create a vortex into something like a pressure gauge f means failure vaillant. mind you they zee germans...........:P maybe it was intended. immagine putting a rubber seal on a noisy heat exchanger and shipping it out as fully tested. then blaming installers. gas safe did nothing.

I'm really keen to talk to you about heat pump installations. I'm plumbing my own houses using boilers today with new pipes etc. I'm trying to make sure that I can put a heat pump into it in the future with little or not change. I'd be keen to have a telephone conversation or see one you on site at one of your installations. I cannot see the UK creating enough hydrogen. We plan to generate 10% of our gas needs with hydrogen by 2030 and ban natural gas boiler installation by 2035 - so where will the other 90% come from by 2035? Look at it this way: The current plan is not to replace 90% of natural gas with hydrogen before the natural gas boiler installation ban. Also, what is the point of building all that extra electricity generating capacity to create hydrogen when we can just send electric directly to the house? Because of the COP of a heat pump, we can have less power stations compared to what we need to generate hydrogen.

The filter is there to tell you if your inhibitor is working!!! Plus catch bits of sludge.

As always great information and a great video, keep the great work up.👍👍

I'm not a plumber so my experience is limited to one system (the boiler in which died for reasons I think unrelated to crap in the water and was replaced only last week). But it was a bit of a bodged system, I suspect run for some time without inhibitor, and the water in it was FILTHY. When the boiler died I took advantage of the downtime to remove radiators one by one and flush them out, in the garden, with clean water. Honestly, the amount of black sludge I watched going down the drain was impressive. But when I cleaned the Spirotech filter only a few weeks previously the amount of crap it appeared to have caught was minimal. In fact the only device which seemed to catch sludge was the plate heat exchanger, which I had replaced earlier this year. There's now a sparkly new Worcester Bosch boiler up on the wall, with their own brand filter which looks a bit like a Magnaclean. I'll be interested to see if it catches anything.

have you worked on warm air systems eg johnson starley imbased in south west SCOTLAND

I kind of would like to get your opinion on the filters from Caleffi, if at all possible.

Gloworm boilers come with a metal body filter which if fitted extends the warranty.

For the average consumer they probably couldn't care less I imagine unless their plumber tells them why they need one etc etc. As a DIYer, I went for the 'ease of install' and cost approach - i.e. inline install (not offset connections) and cost (around £60 in 2018) so the Flomasta (Screwfix) got the gig - I can't compare to others but on a retrofit, it has collected a lot of crud early on and allows me to top up the inhibitor when needed as I progressively decorate and remove radiators one-by-one (I flush them out outside with a hose). It works for me, I dislike the slightly plastic valve key which is far too flimsy and the lid which also feels a little scary when undoing or tightening...but it happens infrequently and touch wood I've not had any leaks (I keep a yogurt pot underneath in case!) As a product, they probably don't do any harm provided they are cleaned periodically and it helps to monitor the state of the system - it baffles me that the prices are going up (now £85) rather than down since every man and their dog seems to have similar designs!

air and dirt seps is definitely needed and mag filters help condition the system water

Spiro is favorable imo over any plastic filter I just wish Elysator made smaller version of the Sorbox

Inhibitors are just a marketing program

Good vid 👌

Interestingly the formation of magnetite on the inside of many industrial boiler systems is promoted (indeed is essential in many boilers) as the magnetite forms a layer preventing further corrosion of the steel ... so once formed there should be no further corrosion.

Given the tiny amounts being removed shouldn’t his settle in the bottom of the radiators where flow is slow as maybe after 30 years might give a cold spot?

Gotta be the Adey pro 2 for me all day long, easiest to use and great for flushing/dosing chems.

Magnaclean is my favourite , as like you pointed out adding chemicals is a doddle. The worst are the boiler buddys (cant remember who makes them) but ive had 2 shatter when trying to get them apart.

Magnacleanse is by far the best in my opinion although the 1st generation are shocking.

My #1 rule when hiring plumbers is if I can't understand more than 7% of the words that come out of their mouth then I don't care what they think.

Love the magnaclean filters but always carry a seal kit mainly just for the large O ring on the lid, the old red ones are the worse for leaking. As you said they are also great for dosing with chemicals .

What would you recommend fo rproper long-term limescale prevention?

I have an old fashioned vented system. Recently changed the boiler, now have air bubbles gurgling through the pipework in places. The pump isn't drawing air from the vent or the header tank, and there's no discernable leaks, so where is it coming from ?

Have a filter system with combi Boiler. I know what it does, but to the every day plod in the street, I don't notice what it does for the water system. I think the water quality is good in the north east

Baxi mi small print says filter must be fitted for warranty also shock arrester

magnaclean all the way

Thanks for that, very informative

Fernox Omega metal body. Really well made, compact and seems to do the job.

I have a magna clean same as the one you showed with wire mesh on the bottom. Does a great job with collecting particles. I have not ever power flushed in 20 years.. ever 7 years I remove the rads and hose it down in the garden

So informative thank you!! Please keep posting!!! 👍🤘

British gas now fit fernox omega filters. Full metal but with an internal magnet.

Great video mate, We use a adapted weed sprayer to inject chemicals into systems you can make adapters to fit anything will pump in up to about 1.5 bar no problems. We have also used to add air to a radator to allow temporay expansion so system can function till new vessal fitted works really well.