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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Balancing radiator conundrum https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1458309401 Message started by londonman on Mar 18^th, 2016, 1:56pm

Title: Balancing radiator conundrum
Post by londonman on Mar 18^th, 2016, 1:56pm

I was trying to balance up my radiators. I'd got to the point where you have all the valves (lockshields and TRVs) open and then turn on the CH and note down the order in which the rads heat up. Thing is the rads furthest from the boiler never heated up!

Do I need a different pump?

Title: Re: Balancing radiator conundrum
Post by thescruff on Mar 18^th, 2016, 9:30pm

Turn all the other rads off and if the furthest one gets hot no you don't.

Last one leave the LS valve fully open then work your way back to the boiler turning each rad off 1/2 turn more than the rad before.
example 2nd last 1/2 turn, 3rd last 1 turn, 4th last 1.5 turns 5th last 2 turns, etc then you can tweek then so they all get roughly the same.

Also check the TRV isn't stuck on the one that doesn't work

Title: Re: Balancing radiator conundrum
Post by londonman on Mar 19^th, 2016, 9:33am

OK..thanks for that. Will give it a go.

Title: Re: Balancing radiator conundrum
Post by londonman on Apr 7^th, 2016, 3:22pm

I'm afraid that I have to report back a complete, abject failure.

I've gone the other way which is to leave the rad furthest from the boiler fully open, sh*t down all others and then gradually crack them open a tiny amount until I can hear water flowing.

Title: Re: Balancing radiator conundrum
Post by thescruff on Apr 8^th, 2016, 9:26am

But did the one that didn't work get hot or is there another problem like a blocked pipe or stuck valve

Title: Re: Balancing radiator conundrum
Post by londonman on Apr 8^th, 2016, 12:38pm

It sort of got a bit warm. The valve isn't stuck but the pipe (plastic) is probably partially blocked by some black crud. That's the trouble with that early Hep20 plastic pipe.

I'll have to live with it !

Title: Re: Balancing radiator conundrum
Post by woodsmith on Apr 8^th, 2016, 5:40pm

londonman wrote on Apr 8^th, 2016, 12:38pm:

It sort of got a bit warm. The valve isn't stuck but the pipe (plastic) is probably partially blocked by some black crud. That's the trouble with that early Hep20 plastic pipe.

I wonder if anyone has tried taking Hepworth to court over their crap pipes?

Title: Re: Balancing radiator conundrum
Post by londonman on Apr 9^th, 2016, 10:14am

I don't know. What I do know is that I never got a reply to my polite email to them asking for their comment on this blocked up pipe.

This pipe connected to a copper pipe as part of the same run and yet the copper pipe remained clear.

Ergo Hepworth pipe is crap.

Title: Re: Balancing radiator conundrum
Post by thescruff on Apr 9^th, 2016, 10:59am

You should try and change it as it will cause corrosion in the rads etc.

Have you tried a mains flush on the dodgy pipe ??

Title: Re: Balancing radiator conundrum
Post by londonman on Apr 9^th, 2016, 6:30pm

I removed as much of the old pipe as I could but there is some left in inaccessible places and pretty much blocked. I tried power-flushing but unless there is some sort of flow to begin with, PF doesn't work.

I've also put a Magnatite in circuit - wish I'd known about them (if they were available 20+ years ago, that is) when I put the system in.

Title: Re: Balancing radiator conundrum
Post by Headrush on Apr 10^th, 2016, 9:54am

That looks awful! Is it just Hepworth pipe or is this a problem with other such plastic plumbing? Because I've started using JG stuff more often than I would prefer, being of the oldskool variety, but it does save a shed-load of time. I particularly like using it in attics as I find them to be a major fire hazard and often difficult to navigate..

Title: Re: Balancing radiator conundrum
Post by thescruff on Apr 10^th, 2016, 10:18am

Headrush, The 1st plastic pipe was for domestic water, but was used by plumbers to lash up heating systems and save bucket loads of cash. however it was discovered that it was permeable (let in air) so Barrier pipe was introduced.

Londonman.

Use a couple of hose pipes, connect one to drain and one to the pipe then blast it with mains pressure, clears most blockages.

Warning. disconnect the pipe from the radiators as depending on mains pressure you can damage the radiators and boiler

Title: Re: Balancing radiator conundrum
Post by woodsmith on Apr 10^th, 2016, 12:17pm

My Hepworth pipes looked exactly the same as Londonman's, ie blocked up with solid black material. My pipe specifically said along its length suitable for central heating, so you can't blame plumbers for using it and I think Hepworth have a lot to answer for.

I tried blasting my system clean with mains and got a full bucket of solid black magnetite out of the system, some pipes wouldn't clear though ( even with 5 bar air pressure from my spraying compressor) and I replaced those and fitted two Magnacleans, but within 12 months half the rads had stopped working again.

Title: Re: Balancing radiator conundrum
Post by londonman on Apr 10^th, 2016, 9:57pm

thescruff wrote on Apr 10^th, 2016, 10:18am:

You haven't seen our mains pressure !! Or lack of.

Title: Re: Balancing radiator conundrum
Post by thescruff on Apr 10^th, 2016, 11:46pm

I have if it's in London ;D