Cleaning F+E Header tank & adding cleaner to heating sys

[DIYNotIan]

Hi all

I've got a plumber booked for the New Year who is going to be doing some work on our central heating system. He is going to have to do a drain down, and so a week or two before he arrives I am going to add some Fernox F3 to the system.

Does that sound like a good idea?

If so, I want to make sure I put it into the correct header tank! In our loft we have three. One small one and two larger. One of the larger ones is uninsulated and has no lid. I've never been sure whether it is actually in use or what it's purpose is. So aside form asking which tank to put the F3 into, it would also be helpful to know what the uninsulated/lid-free tank might be there for.... [Update - I'm going to deal with the issue of the two linked large tanks in another thread]

Here are some pics. This first one shows the two insulated tanks. The third uninsulated one is out of sight behind the large one.

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• DIYNotIan
• 18 Dec 2014
• 1

A view looking the other way (so that the "hidden" tank is now at the front and the small one cannot be seen). Sorry for the crap angle but it's all a bit tight in there!

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• DIYNotIan
• 18 Dec 2014
• 1

And here are a couple of shots of the uninsulated lid-less tank:

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• DIYNotIan
• 18 Dec 2014
• 2

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• DIYNotIan
• 18 Dec 2014
• 2

Any help would be hugely appreciated. And as ever, thanks to all you very helpful folk.

Max

 

[Dan Robinson]

The little one in the first picture.

 

[DIYNotIan]

Thanks for that.

I've been told that I need to clean the header tank and remove some water before adding the Fernox F3.

Has anyone got any tips on how I do that please?

Please note though that this is all very new to me so the more info the better!

Cheers

 

[Burnerman]

There's sure to be a bit of rusty shoite in there....how about tying the ball valve up, and getting in there with a wet vacuum cleaner?
John

 

[stardanny]

That look like two tanks coupled together. As the ballvalve is in other large tank, where is the outlets?

Also it should have a lid on it.

Daniel.

 

[DIYNotIan]

That look like two tanks coupled together. As the ballvalve is in other large tank, where is the outlets?

Also it should have a lid on it.

Daniel.

When I get up there I am going to take a good look at how the two tanks are linked and try to get a better understanding of what the heck is going on with those two tanks. Something doesn't seem right.

There's sure to be a bit of rusty shoite in there....how about tying the ball valve up, and getting in there with a wet vacuum cleaner?
John

I don't have a wet vacuum cleaner. In fact, at this stage it sounds similar to a sky hook to me!!! So I think I'll just clean it by hand....

I have been getting some help on another forum and it would seem that the whole process is far more involved than I first thought.

I've also been reading the Fernox info sheet for F3....:

http://www.fernox.com/files/Fernox/Content/PDF/English/F3 Cleaner 500ml with CB logo v2.pdf

To begin with, the instructions state: "First drain and refill the entire system with plain water. For optimum results the entire system, including drop feed radiators where fitted, should be completely drainable."

The instructions go on to say that after the F3 has circulated for a week: "Drain and flush thoroughly, at least twice, until the water runs clear."

Is all of this necessary?

If so, I keep thinking to myself - I'm already draining the system! Is that process any different to a "drain down"? I'm guessing that IT IS a drain down. And if so, I'm starting to wonder why I'm going to be paying the plumber to do a drain down and add inhibitor when it would seem I've already done half - if not more - of the work before he even comes.

So could I propose to the plumber that before he comes I will:

1. Clean the header tank
2. Drain and refill the system with clean water
3. Drain enough water to be able to add the F3 via the header tank (i.e. to be able to pour into into the outlet pipe).
4. After a week, drain and refill the system at least twice (until the water runs clear).
5. And, if I do step 4 the day before he comes, I could leave the system drained overnight, so that when he arrives he can change the TRV straight away, add the inhibitor, refill, balance, and away we go?

Am I over-thinking this, or misunderstanding or missing something? That's what a sleepless night does for you!!!!

Many thanks

 

[JohnD]

Bale out the tank first and sponge it clean. Wipe it round with bleach, including the lid and valve.

I would add the chemical during stage 2, so that it is all drawn down and thoroughly mixed in. I would have used Sentinel X400 which is a mild, non-aggressive cleaner and can be left circulating for several weeks, but I expect the Fernox one is just as good. It might even be better. Avoid acidic cleaners as they may cause damage.

step 5 looks OK to me but tell the plumber so he doesn't schedule half a day.

Have you considered fitting a system filter? It will cost about £100 but on a dirty old system is very worthwhile, and you will be gratified to empty it periodically and see how much sludge it has collected. The chemical you use will loosen old sediment and there will still be some remaining even after you have drained and rinsed it a few times. The filter will slowly capture circulating particles.

Remember to add inhibitor during final fill (don't just pour it into the tank after filling) and tie a label on saying date and product used. Keep an eye on the tank in the next couple of months in case you get fungus or bacterial slime. For some reason it often occurs after a clean, possibly because the metallic sludge has been removed and the clean water is not toxic.

 

[Scarum]

Keep an eye on the tank in the next couple of months in case you get fungus or bacterial slime. For some reason it often occurs after a clean, possibly because the metallic sludge has been removed and the clean water is not toxic.

Ahh so this explains why I had slime after my system clean out! Thanks for the insight, makes a lot of sense now

 

[DIYNotIan]

Thanks JohnD - that's a fantastic help.

OK.... I've been up and now have a tank you could more or less eat your dinner out of!

I do have a few follow on questions if I may. Sorry for being a bit greedy with the questions....

1. The draincock looks in a poor state... I'll load up a photo tonight when I get home. I'm a little worried about trying to drain from it and breaking it and wondered whether you think I would be silly to try - especially given the time of year and the chances of getting help should something go wrong.

That leads me to...

2. How essential is the cleaner. Reading around on the net, seems that everyone talks about inhibitor but only a few talk about using a cleaning product. With time being of the essence, and the potential problem with my lack of skills/knowledge and a dodgy draincock, should I consider forgetting about the cleaner entirely?

3. A quick aside question... Both the F+E tank and the first large water tank have vertical copper pipes coming out of them. What are they for?

Many many thanks

Max

PS - can we just keep this thread about the F+E tank to stop things getting confused and mixed? I will write another new thread about the problems with the linked large tanks.

 

[JohnD]

the rubber washer in the draincock is likely to be perished. You can poke it until water comes out, but be prepared to fit a new cock. This will be fairly easy if it is compression fitting. Or just fit a new one near a drain or by the back door. A full-bore valve is even better as you get a faster flow which helps wash out sediment. I used a washing-machine valve, that you can put a hose connector on. Best to put it on a pipe stub so it will not get so hot in normal use. You can put a capnut on it as second-line defence against leaks.

You might be describing vent pipes, in an inverted "U" shape.

I am a great believer in keeping old systems clean. Much better, and easier, to do it before you get a blockage.

You can also drain by undoing a radiator valve, and swivelling it round away from the radiator. Some hose adaptors may fit.

If you think you will be able to complete the drain in about 4 weeks, you could use Sentinel X400, as that's its maximum recommended circulating time.

 

[DIYNotIan]

the rubber washer in the draincock is likely to be perished. You can poke it until water comes out, but be prepared to fit a new cock. This will be fairly easy if it is compression fitting. Or just fit a new one near a drain or by the back door. A full-bore valve is even better as you get a faster flow which helps wash out sediment. I used a washing-machine valve, that you can put a hose connector on. Best to put it on a pipe stub so it will not get so hot in normal use. You can put a capnut on it as second-line defence against leaks.

I'm a bit scared to do any of that to be quite honest. I may speak to the plumber and ask/plea(!) for him to pop by asap and change the draincock. I can then be getting on with the clean etc before he comes in early January.

Oh, and here's that pic I promised earlier:

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• DIYNotIan
• 21 Dec 2014
• 1

You might be describing vent pipes, in an inverted "U" shape.

Quite possibly... Here are a couple of better pictures. If they are vent pipes, what are they used for/how do they work?

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• DIYNotIan
• 21 Dec 2014
• 2

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• DIYNotIan
• 21 Dec 2014
• 1

I am a great believer in keeping old systems clean. Much better, and easier, to do it before you get a blockage.

OK, I'll do my best to get it done then.

You can also drain by undoing a radiator valve, and swivelling it round away from the radiator. Some hose adaptors may fit.

Sounds a bit scary and like something I could potentially bodge up!

If you think you will be able to complete the drain in about 4 weeks, you could use Sentinel X400, as that's its maximum recommended circulating time.

He's coming on the 5th, so unfortunately not.


One more question if you don't mind... When you add something like a cleaner (or Inhibitor, etc) to a system, how is it done? Do you need to somehow funnel it into the outlet in the F+E tank?

Thank you so much for all the help.

 

[DIYNotIan]

Regarding the vent pipes, I understand now (I think). As the water heats up and expands, it increases in volume. The excess air and water as a result of this expansion has to go somewhere. It goes through the vent pipe back into the tank.

Is that right?

If so, mine look a lot longer than others I've seen! Hopefully they are ok though....

As a quick aside, it's funny... As I cleaned out the tank I kept wondering my there was muck and rust in there. I thought to myself "this tank only ever provides water for the system, water never comes back from the system to the tank, so how does all the crap get in there". Through the vent pipes I suppose....

 

[JohnD]

It actually goes up and down the feed and expansion pipe, as it expands and contracts with temperature. It only rises up the vent pipe if the F&E pipe is blocked, or the boiler overheats.

 

[DIYNotIan]

Oh right, I misunderstood in that case. Thanks for clarifying. So it is there very much as a safety measure; a "just in case". As you have explained it, there would be no need to lag those pipes... Or would there for some other reason I have not thought of?


Back to the F3 Cleaner problem. I've had another idea...

Could I bail out the water from the F+E tank by hand so that it is below the outlet pipe level. Then bleed each radiator a bit until I have extracted 600-700ml of water. And then add the F3 through the outlet pipe opening in the F+E tank? Would that work? I'm presuming that as I bleed each radiator gravity will force the water in the pipe in the loft to fall, and therefore when I add the F3 it will get into the system and circulate properly while we wait for the plumber to come. Knowing me though I've probably missed something major so I won't do anything without a thumbs up!

Huge thanks

Max

 

[JohnD]

You need to bale out the F&E tank and then drain at least a bucketful of water out of the radiators. Then add the chemical to the tank and allow it to refill, stirring, the contents will then flow down to the radiators.

If you can find some way to pour it into the F&E pipe that would be even better, but you have to wash it down with a bucket of water or it will lie in the pipe.