Locating and resolving blockage

Im afraid you have two choices neither one you like from your post above, the easiest is to have the system power flushed Yes there are chemicals involved but they have a similar Ph to coke. Its the flow of the power flush unit that does the donkey work. these units work even better when combined with a magnetic unit that combines into the units pipework preventing scale going back into the system. There is of course no guarantee that this will clear you problem so you would be left with the lifting floorboard issue. One way to find the exact spot where all heat stops is to use thermal camera technology but the companies who do this will charge from £400 upwards. Sorry can't think of any better way to sort your issue.

 

I'd connect the rad valve that's only dribbling to a mains water tap with some pushfit pipe and give it full pressure, Like daves suggestion it might not work, but it won't cost owt,

 

you could try my secret weapon, its worked a couple of times for me,

 

Whitling, you say that rad had some crud in it, so no doubt the rest of your system has too.
I can't see any proper solution than to shift that stuff out. You have a 'sealed' system - is it a combi boiler? Is it a condensing type? If so, expect expensive trouble when that crud blocks your PtoP heat exchanger.

Yes, sometimes adding cleaning chemicals will highlight a leak, but that's no reason not to use them; that leak is going to show itself one day anyways... What usually happens is that a radiator - which is made from steel, so rusts - is partially corroded through from the inside. The oxide then kinda blocks and covers that thin rad wall and keeps it from leaking! Until you add cleaners...

But, if that rad is gonna go now, then it will be going in the future anyways. And there's a very good chance it just won't go at all if you sort your system now. And usually the hidden pipes will be ok as they don't rust. Ok, perhaps there's a poor joint somewhere that was prevented from leaking by the crud, but - hey - that's unlikely.

It was promising that you shoved your pressure up to 3.5 bar ( ) and nothing leaked, so I reckon you'll be ok.

Soooo, what I would suggest is; 1) fit a filter on the return. I don;t know which is best, but I understand the latest ones work by both magnetic and 'swirling' out sediment (like a Dyson). It'll cost over £100 for a good one, is easy to fit, and IS WORTH IT. As you start to slowly shift that crud, you want it collected! (2) Shove a double-dose of Sentinel X800 cleaner or similar. Fire up, and run your CH system when it's cold enough to justify (getting chilly in the mornings...) and keep checking the filter (so get one that's easy to check and clean!)

Keep the valves to the 'blocked' rad fully open and the others nicely shut but still open - say lockshields at a quarter-turn open and other ends fully open.

Sit back and let it do its job. No rush - give it weeks.

I did this and it fixed my blocked heat exchanger, and also removed a disgusting amount of sludge from my old system. I had it running for a couple of months with no adverse issues (apparently some older cleaners were reputed to cause problems with prolonged use).

It needs sorting, man, so sort it. You need a darned good cleaning - there is no other option .

 

You wanna shift a blockage or not...

I suggested X800 'cos it's powerful and sorted my boiler for me - and saved me from a multi-£100 bill. Oh, and by choosing wisely, you can pick them up for a lot less on t'Bay - I think I paid less than £20 for 2 bottles

I fitted a Magnaclean, but only because I got one for a good price on ebay too... Just read reviews on all the known makes - Magna, Fernox and Sentinel (and possibly others.) They are being improved all the time.

The above is what I would do in your situation - I'm not saying 'do it'.

But I'd certainly do it before chopping into assorted T-pieces and junctions in the hope that it's where the blockage is.

And... if you have a blockage that bad, then you have a lot more crud in your system than you think. That NEEDS to be shifted.

A power-flush will set you back many £100's.

 

if its as bad as this flushing won't move it,

 

Not just a pretty face are you Tom.

 

I know what you mean, Tom, but if the cove has a wee flow going through the blockage, them chemicals will slowly remove the layers of it as it passes through - bit by bit, layer by layer, over a few weeks.

I had a pretty thoroughly blocked PtoP exchanger, and you know how narrow the waterways in these are. The X800 made a noticeable difference in minutes. What I did was to fill the Magnaclean with neat X800, and then run the CH for just a few seconds in order to get that 'neat' dose up into the boiler - then I turned the hot tap on and of repeatedly. I added a further dose, and repeated. The filter took a half-bottle each time. After doing this with the 2 bottles, I was getting hot water again. It really was that effective. Ok, I know that the amount of sludge it takes to block an exchanger is small, but when you think that the actual amount of treated water flushing it through is also tiny - 'cos it's the same wee bit that gets recycled around within the boiler - it was very impressive.

After running it all for a couple of months (I didn't really mean to leave it that long, but couldn't be assed flushing out...), I had emptied the filter a few times and removed a nice dollop of sludge each time. The boiler was working perfectly, and I believe it was even quieter than it had been for some time.

Finally hosed through the whole system for a good half hour until the water coming out was only lightly brown when filling a bucket (on removing the filter body, you can connect a flush and drain hose using washing-machine type connectors on to the fitting's ends - that made life a lot easier).

Refilled with X100 inhibitor, and I still check and clean the filter every few months (I should do it again soon.)

That was a year ago - absolutely no problems since.

Anyways, it's the cove's call .

 

With a plate heat exchanger DA the easiest way to unblock them is remove it and soak it in a bucket of Fernox DS3 for about an hour, works 99.9% of the time.

 

Funnily enough, when the first exchanger blocked and I got a cove in to replace it, I did experiments with the removed one chust for interest. Looking into the bores, you could see the black coating of the oxides. I happened to have some water-based rust remover which you dilute a goodly amount before use and made up a solution. I filled the exchanger to the brim and next day it was shiny and clean inside when I hosed it through - bits of black were washed out.

Mind you, I'd rather not go to the hassle of removing the exchanger if possible. I'm pretty confident that the current exchanger is pretty darned clean having had all that cleaner go through it for months...

 

Whitling, this is the way I look at it; Your system is full of sludge. Not one pipe, not one Tee, not one bend - your whole bludy system. You cannot have so much carp that a pipe is blocked without there being carp everywhere else too.

Every single rad will have a pile of **** sitting in its bottom-middle. Every length of pipe will have some coating. All the lowest points of your system will likely have more sizeable deposits and some parts - as you know - are effectively blocked.

That's a shed-load of carp.

So, chopping out a fitting ain't going to sort that. I'd suggest that even a power-flush will struggle to do it all.

And thinking that "oooh, I daren't risk a flush or chemicals in case it causes leaks" is just sticking your head in the sand. IF your system has parts which are so thin that they may leak with a clean, then they are going to leak anyways pretty darned soon. At least this way you'll be monitoring the system and checking your rads on a daily basis - much better than it decides to burst while you are away on your hols.

And the good news is that's it's very unlikely to be a hidden pipe that 'bursts' - it'll almost certainly be a visible radiator.

And the very good news is that the chances are nothing will leak - that's usually the case. And you have cranked your system up to 3.5bar without issues, so you've effectively done a decent pressure test with no pops (you'd normally have your system at around 1 bar).

AND you DO need a filter, man. You need one at some point - you'd be nuts not to fit one. Whatever 'cleaning/unblocking' you do now, there will be constant additional sludge being loosened over time and swimming around your system. And, let's face it' your system is well dirty.

So, since you should really fit a filter anyway, then fit it now. Along with a double-dose. You might possibly find that this is all you need to do, so you've saved many £100's and lots of hassle too.

I'm not telling you what to do, but you be a complete raving imbecilic loony if you didn't.

You've effectively got nothing to lose and a potential shed-load to gain.

 

Blimey!

You can't tell, but I'm lying prostrate on the floor in front of my PC, arms extended in worship