The inhibitor is mainly there to prevent your radiators rusting, from the inside and producing magnetite which obstructs the radiator and pipework. On more modern boilers, it can block up the passages within the boiler.
Intergas heat exchanger design
- Thread starter JonathanM
- Start date
The inhibitor is mainly there to prevent your radiators rusting, from the inside and producing magnetite which obstructs the radiator and pipework. On more modern boilers, it can block up the passages within the boiler.
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So maybe not blocked waterways, just rusty radiators. We put a double dose in the last time the system was drained, but that was quite a few years ago now. They all warm up well still, though.
As long as the system doesn't need topped up regularly then the inhibitor concentration will stay stable for a good while. As the system is sealed the the only way the concentration can really be diluted is by adding in fresh water. The chemicals can break down over time reducing its effectiveness. Some say top up every year, some say whenever the system needs topped up, the only really way to know is to test the system.
The inhibitor is also PH neutral and conditions the system, up to a certain point of dilution, though once it's past that point then depending on whether the system goes acidic or alkaline can then determine what corrodes , alkaline systems are bad news for aluminium, acidic for both aluminium/copper/steel/etc. A system high in dissolved O2 without inhibitor will increase corrosion in the mild steel rads and promote sludge, so always best to keep a check on it.
Some say there can never be too much inhibitor but there is more and more evidence coming out where too high a concentration can have an adverse effect on certain plastics, which some systems are containing more and more of, pump issues and a lot of mag filters are made of.
The inhibitor is also PH neutral and conditions the system, up to a certain point of dilution, though once it's past that point then depending on whether the system goes acidic or alkaline can then determine what corrodes , alkaline systems are bad news for aluminium, acidic for both aluminium/copper/steel/etc. A system high in dissolved O2 without inhibitor will increase corrosion in the mild steel rads and promote sludge, so always best to keep a check on it.
Some say there can never be too much inhibitor but there is more and more evidence coming out where too high a concentration can have an adverse effect on certain plastics, which some systems are containing more and more of, pump issues and a lot of mag filters are made of.
That's all very useful info. I hadn't realised it was so complex.
I'm sure they used Fernox F1. But if I'm wrong, is it OK to mix brands?
As regards testing it, is that easy? BG do my annual service and don't take very long TBH. Is testing the system water sort of thing you might expect at a service. I'm wondering whether to ask them.
I'm sure they used Fernox F1. But if I'm wrong, is it OK to mix brands?
As regards testing it, is that easy? BG do my annual service and don't take very long TBH. Is testing the system water sort of thing you might expect at a service. I'm wondering whether to ask them.
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You can buy test kits/litmus tests that will show concentrations .... each manufacturer tends to have their own, depending on the active ingredient, whether it be Nitrites or Molybdates. They can be expensive though.
Better to do it yourself, then you know it is done and done correctly.
A long time ago, I had some universal indicator strips, from when I used to ferment my own probiotic yogurt. I'll see if they still work.
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Your strips will only work if they can test for the presence of those specific chemicals and whether they are in the correct concentration or not. Not just if they are present.
I just meant I would do a basic pH test.
Tested the strips with white vinegar and bicarb. Still seemed to read OK. If true, system pH is between 7 and 8.
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I have replaced a few TRVs on neighbours rads over the years, two have Glow-Worm boilers > 10 year old and before I suggested adding some inhibitor had never seen a drop I would think, on drain down the water looked quite good so wonder what the heat exchangers material is. Semi sealed systems (non combis).
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I've got an intergas boiler, been running well for the last 3/4 years or so, they are quite simple inside when you have them open, my old glowworm boiler was complex compared to the intergas... one other nice feature I recently spotted, is the pcb is protected from any leaks as the casing opens from underneath and its sealed from the inside of the boiler.
And the Expansion vessel is on a hinged bracket, so you can access it and swing it to one side.
Also its very quiet, but I suspect, most modern boilers are now.
And the Expansion vessel is on a hinged bracket, so you can access it and swing it to one side.
Also its very quiet, but I suspect, most modern boilers are now.
Inhibitor is an old way of doing things. With the use of an aerator and softened water and a ph check carried out you don't have to use inhibitors. I believe this is a German standard.
Anyway these videos my installer advised me to watch as this is what he recommended (which I went for) and it's been reliable for past 2 years. Only thing I've been disappointed with is the evohome controller, but that's down to Honeywell just being really rubbish with updating/supporting their systems.
Spirotech Rv2 video
After cleaning hex
Before cleaning hex
Before cleaning hex
The intergas heat exchanger does suffer from corrosion
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