Brown sludge in header tank. Boiler cuts out after 5 minutes

[Doctor Drivel]

Thanks Slugbabydotcom & The Baker for the last two posts which seem to address the problem

It looks as if it is a severe blockage below the pump. We drained the system and took off one piece of the pipework today and fushed again but the boiler still locked out after 10 minutes so we didn't get it all. Not much more we can get to without having up the recently fitted carpets and tongued & grooved floorboards!

Looks as if I will have to go with Powerflushing as the problem is mainly in the pipework not the rads and even if we need a new boiler most companies require an old system to be flushed.

I guess there could be quite a lot of muck throughout the whole system and its not the weather for taking off 16 radiators and flushing them in the garden and this would not help clearing debris in the pipework.

Thanks to all who posted.

You could attach the mains to the system and cap off the cold feed and open vent. Then close all rads and open one at a time and open the mains tap. with the drain hose attached. Make sure the flow does go through the rad. This can clear the rad and the pipework along the way. Worth a try.

 

[patagonia]

I wonder if the plumber who did the flushing etc. last time put in a double dose of chemicals. It sounds as though you have a pretty big system. Do you know what make of inhibitor he used?

£500 doesn't sound too bad for a system your size and I should have thought it wd cost just as much if not more to take all those rads into the gdn etc. We were quoted £1000 for a power flush last yr; glad I didn't rush into it as we have now been told we don't need it as all rads. get hot and it wouldn't solve the boiler kettling and other noises.

Do let us know if the p.f. solves your probs.

 

[Jane57]

No he didn't double dose. He used Sentinel X400 then the X100 inhibitor after the system was drained a refilled 4 weeks later. (That was when it was done 4/5 years ago when we fitted new radiator valves)

This time he added the X400 and the boiler cut out about an hour after and will not run now for more than 5 minutes. Now we have had no heat or hot water for a week and its another 12 days before we can get it Powerflushed!

 

[patagonia]

From what I have picked up, you would need more than one bottle of both if you have a large number of large rads as we do also. Perhaps the experts on here could enlighten us as to whether they do any calculations as to the amount of chemicals required or just stick in what they think might do. I gather one can't overdose with Sentinel. If you can't get your p.f. done for a while (I sympathise as it's taking us ages to get anyone to quote for our work let alone do it) I wonder if it might be worthwhile putting in another bottle of X400 in the meantime to see if it loosened the sludge in the pipes and whether turning up the pump would help dislodge it or would that be dangerous or bad for the boiler. What do the professionals think? 12 days is a long time to be without heating or h.w. I intend to have a Magnaclean installed as I'm not convinced they will get all the muck out as the boiler is in the cellar and the drain off in the hall. Best of luck.

 

[Jane57]

Seeing out system will not run at all now as the boiler cuts out after just 5/10 minutes and does not heat up anything at all except the boiler I don't think it worth putting anymore in. I think the X400 relies on the heat to work and needs to circulate in the sytem not just sit in it from what I am told.

We are having one last try on Friday & cutting out another piece of 22mm copper pipe where the magnet is still very attracted to and see if that cures it but it will depend how far the magnatite build up goes. I was wondering if once the 6/8 inch piece of pipe is removed if we could attach the hose to the pipework and give it a blast of mains pressure?

 

[easyflow]

Think at this point your only option is cutting out sections of heating pipe work, its my guess you will find a blockage that is coal like material and even a screw driver will have trouble diggin it out, had one like this last year 22mm T close to the boiler was blocked solid, but once clear the system was spot on, sorry for the bad news.

 

[Jane57]

Re :-easyflow
"Think at this point your only option is cutting out sections of heating pipe work, its my guess you will find a blockage that is coal like material and even a screw driver will have trouble diggin it out, had one like this last year 22mm T close to the boiler was blocked solid, but once clear the system was spot on, sorry for the bad news."
-------------

I hope thats not the case as it sounds very worrying and expensive!

The thing that puzzles me about that is surely the sytem would not be draining & filling if there is such a bad blockage? Surely you could think the system has drained when it stops running out and then you get a nasty surprise when you cut the pipe! We have now drained & filled the system 4 times and each time it appears to drain & fill will no problems. We have checked each radiator and they are all full of water after we refill.

My plummer still thinks the boiler may have devleoped a fault but we had out boiler service guy come in to check it and he says its fine so we go around in circles.

I am thinking of buying a Magnaclean and getting that put in but I doubt we can get it to run long enough for it to do much.

 

[Rotunda82]

I dont personally think that a power flush will help your situation yet as if there is a solid blockage it wont be removed.

Firstly your plumber needs to remove sections of pipe to identify the location of the blockage - normally around the pump as mentioned before but also be sure to check where the cold feed pipe is connected into the heating system as a lot of blockages occurr there

When the blockage is removed and the system can circulate I would then look into flushing of some kind

Re : draining and filling - the system can still drain and fill well through the return pipe if the blockage is in the flow pipe so the fact that it has drained and filled relatively easily wont rule out a blockage