Flushing Radiator Sludge

akira181

Long story short, my living room radiator was freezing on the bottom half so I took it off the wall and flushed it out in the bathroom. Tons of sludge came out and when the water ran clear, I drained it down (turned black again towards the end), dragged it back to the living room and rehung. Draining created quite the mess so I didn't want to flush again when I saw the drain water turn black again (hindsight this was a mistake). Now the back panel is hot along the bottom but the front panel is still mostly cold along the bottom (although only a third opposed to roughly half).

In order to save my back, fingers, and avoid risking my toes (the radiator is far heavier then I imagined, about 50kg empty), can I just isolate the radiator, remove the bleed valve, and end cap from either side of the top of the radiator and flush the rad in situ? Or does it have to be from the bottom?

DanDare999

Flushing it in situ as you describe is unlikely to remove sludge sat in the bottom of the rad. Is it just the one rad you're having problems with or the whole system?

If it does work then spread the word as it'll save ££££'s on power flushing.

bob_a_builder

More a job for the outdoors (if thats an option) than the bathroom I would have thought
When its upside down, a little bit of persuasion from a rubber mallet on the panels where the sludge is would help it flush out 

Bendy_House

From the bottom, Akira.

If your rad valves are supplied by plastic or microbore pipe, there will probably be enough flexibility in them to undo the valves and move them an inch or so aside. That would allow you to connect a couple of fittings to the rad in its place, hosing through and dumping the carp outside. As mentioned above, give the rad a prolonged serious of thumps while you are at it (protect the surface - wrap the mallet in cloth or summat).

And - really - you need to get a magnetic filter installed in the return pipe to the boiler asap, and via that you can add cleaning chemicals.

I'd set aside a day, and do as many rads as you can - certainly all the ones with noticeably cold bottoms.

akira181

DanDare999 said:

Flushing it in situ as you describe is unlikely to remove sludge sat in the bottom of the rad. Is it just the one rad you're having problems with or the whole system?

If it does work then spread the word as it'll save ££££'s on power flushing.

I tried doing a mains water flush from the boiler and filter drain, while opening and closing various rads (kept one open at all times) but it didn't clear out much. The water was black and lots of bits but the effect on the system was minimal at best. Maybe if I used a chemical cleaner beforehand I would have had better luck, but didn't fancy all that dirt coming free and entering a relatively new boiler.

bob_a_builder said:

More a job for the outdoors (if thats an option) than the bathroom I would have thought
When its upside down, a little bit of persuasion from a rubber mallet on the panels where the sludge is would help it flush out 

yeah, I was planning to take it outside and flush in various orientations but soon as I lifted it off the bracket and felt the weight, I quickly abandoned the idea of taking it down 4 flights of stairs! Bathroom in one orientation will have to suffice. I hit it with a mallet while flushing and rocked it back and forth. It feels like I cleared out one panel and that took all the flow, leaving the other panel blocked.

I'm going to see if I can find some fittings small enough that would allow me to attach a mains water and drain connection to the TRV and lock shield ports (space is limited on one side). I don't mind disconnecting the valves, just don't want to remove the radiator again

Bendy_House

Relatively new boiler? Who installed this, and why wasn't your system cleaned?

akira181

Bendy_House said:

From the bottom, Akira.

If your rad valves are supplied by plastic or microbore pipe, there will probably be enough flexibility in them to undo the valves and move them an inch or so aside. That would allow you to connect a couple of fittings to the rad in its place, hosing through and dumping the carp outside. As mentioned above, give the rad a prolonged serious of thumps while you are at it (protect the surface - wrap the mallet in cloth or summat).

And - really - you need to get a magnetic filter installed in the return pipe to the boiler asap, and via that you can add cleaning chemicals.

I'd set aside a day, and do as many rads as you can - certainly all the ones with noticeably cold bottoms.

I can get a fitting onto the TRV side no bother, the lock shield side, it'll be tight. Kinda why I was hoping to do it from the top.

Already got a filter installed and I dose chemicals through my bathroom towel rad as the filter only has a downward facing drain and no option to isolate

akira181

Bendy_House said:

Relatively new boiler? Who installed this, and why wasn't your system cleaned?

cause the engineer was lazy and hopeless. He also got the replacement flue stuck in the hole, hacked the wall to shreds to try and get it out, failed, then cored a new hole and moved the boiler, leaving the mess behind. Hoping to get someone to move the boiler back one day, maybe next summer.

I've been regularly flushing the filter and removing a decent amount of crap, finally decided to flush the rads directly. My whole system is microbore, so a powerflush won't have done much anyhow and probably caused more problems.

DanDare999

akira181 said:

Bendy_House said:

Relatively new boiler? Who installed this, and why wasn't your system cleaned?

cause the engineer was lazy and hopeless. He also got the replacement flue stuck in the hole, hacked the wall to shreds to try and get it out, failed, then cored a new hole and moved the boiler, leaving the mess behind. Hoping to get someone to move the boiler back one day, maybe next summer.

I've been regularly flushing the filter and removing a decent amount of crap, finally decided to flush the rads directly. My whole system is microbore, so a powerflush won't have done much anyhow and probably caused more problems.

That's not necessarily the case.

Why didn't you insist in a powerflush or did the plumber you engaged tell you it would be effective and cause damage?

Bendy_House

akira181 said:

I can get a fitting onto the TRV side no bother, the lock shield side, it'll be tight. Kinda why I was hoping to do it from the top.

Already got a filter installed and I dose chemicals through my bathroom towel rad as the filter only has a downward facing drain and no option to isolate

In theory, this should be doable. The fittings on both sides and top and bottom are usually the same. So, if you remove the TRVs, fit a - what is it, male 1/2" BSP? - on to the remaining valve fitting on the rad, and a hose securely jubilee-clipped on to that and running outside (or to an internal drain), and ditto at the opposite top (again, likely 1/2" BSP Male), I reckon anything you manage to loosen with thumps should be flushed out successfully.

You don't even need to drain the main system as you just shut off both valves (noting exactly what the lockshield is set to, so can be returned there), but obviously care needs taking to catch all the rad's content when you undo the TRV valve.

Or, something I have done to good effect is to buy a 2nd-hand Magnacleanse, which is the professional two-cylinder jobbie, and to plumb that in to where my wee Magnaclean is fitted - the kit comes with the correct adaptors. I then ran that for literally months! Double-dose of X800, and just let it get on with cleaning as the CH was used (my system wasn't 'sludged' up, but there was still enough resilient stuff in the pipes which would render my P2P exchanger ineffectual after around a year - really got on my goat, even tho' I became a bit of an expert in removing, swapping, and acid-cleaning these fellows.)

When it didn't collect any more sludge, I flushed through with clean water (again via the same connectors) to remove the chemcials, and to give a final clean. It's been fine since.

Magnacleanse sold on for the same as bought for.

In your situation, a double-dose of X800 AND lots of thumps :-)

akira181

a magnacleanse won't fit my system without modification and they're awfully expensive on ebay atm.

Also had poor experiences with the magnaclean filters in a previous flat, found they had a tendency to leak, randomly. Boiler got serviced, a week later it started leaking. Replaced the O-ring, leaked soon as the system got hot. Replaced the filter, leaked immediately. Replaced again and worked until the next service and leaked again afterwards. Ruined carpet, laminate, skirting boards, etc. The landlord swapped it with a Fernox TF1 in the end.

I'll give the rad another flush this weekend and see if I can get the last of the sludge out.