Sizing an old radiator or cleaning options of partly blocked?

[pennine_lad]

Trying to size a potential replacement for a double panel with double fins radiator. Have read should size by measuring panel and that is 1550 x 550 which seems to sit between two sizes smaller and larger at eg Screwfix if that is how they have measured.

Cannot be higher as just below windowsill. But 1500 would be a lot shorter requiring some sort of pipe extensions? Estimate of pipe centre to pipe centre is 1620.

The radiator in 1990 build house, soft water is partly blocked as only gets lukewam in correctly balanced system. Can they be cleaned by removing upending, outside hosepipe flush and hitting with say a rubber hammer?

Have had Sentinel X400 cleaner in for maximum of few weeks to no effect. Radiator does get toastie if close all the others off and force through this only.

Thanks!

David

 

[terryplumb]

If that rad heats fully when others are turned off ,then the system wouldn't appear to be balanced .

 

[pennine_lad]

Thanks. Did wonder about that but when under the BG Homecare Scheme the engineer rebalanced quickly while system already hot so that radiator did get hot with all others in system. However, next day after heating up from cold realised had sent all the upstairs radiators cold, when all others previously did get hot. So settings now back to what had recorded before the visit. Most 1.5 turns out.

Have been watching a video of what seems a measurable approach to balancing where set balance valves to measure a 12 degC temp differential from inlet to outlet pipe. Have a thermocouple so may try that.

 

[ETAF]

as only gets lukewam in correctly balanced system

how do you know its correctly balanced
How did you balance

OK, just saw the post - I would try and balance it out yourself
there a lots of post on here and you tube on how best to do that

i just searched here for BALANCING and with the poster terryplumb and found a lot of posts

I watched a few youtube videos and balanced my system when i did replace 3 rads (had to use extensions as the old rads where Imperial and toolstation metric - also used various online BTU calculators to get the size - all using Microbore) and install a new one - which would not get hot - very luke warm

Or describe your setup exactly , and sure a member will answer here for you

 

[gas112]

yep take it off and hose it out from either side , get 2 of you half fill it tip it up and down side to side give it a few wacks with rubber hammer
observing what colour the water is ....This will also confirm whether its a rad or system problem.
Micro bore pipe so you may well have a slight blockage in that

 

[terryplumb]

What do you mean by " most 1.5" ? Is that the number of turns on all lock shields that are opened including the problem rad ?

 

[ChrisJP]

If, as you say, the radiator gets hot all over when the other radiators are turned off, then it's not blocked with sludge - it's just getting a lower flow of water to it when the other radiators are turned on.
In other words the system isn't balanced properly. I think you'll need to make some quite fine adjustments to the other radiator lockshield valves to get this radiator hot without the others going cold or lukewarm.
There's no harm in taking the radiator off and washing it out, but I doubt that will cure your lukewarm problem.

 

[pennine_lad]

Thanks for the advice and comments. The balance valves fully open for all valves is three full turns. The settings for all set by British Gas when a new boiler was installed over 10 years ago was 1.5 turns out of the 3.
The problem radiator currently has the balance valve fully open.
There is microbore in the system so likely won't help.
Have had Sentinel X400 circulating on normal CH heating 63 degC for two weeks and has had no improvement including when forced into problem radiator by shutting others.
Wondered if X800 may be better. Noticed Sentinel had a strong Deposit Remover for the most stubborn deposits but now seems discontinued.

Removing the radiator as suggested seems a final approach. Will get a plumber in for that as not confident in full system drains and refilling not helped by the balance valve on problem radiator leaks when shut or part open, only stops when fully open.

David

 

[ETAF]

i like this guy roger from skill builder - he also does a lot of tool reviews
a couple on balancing - loads on youtube

as i say most of mine are microbore and i did not use a thermomer although i now have a surface one i could use

 

[JohnD]

Radiator does get toastie if close all the others off and force through this only.

Then you have a balancing problem.

For a start, close all the lockdshields and open them all half a turn. Run it for a day.

Does your lukewarm one now heat up?

Do your remaining adjustment but don't turn any of the valves by more than a quarter turn in an hour.

When you drained it after the X400, what colour was the sludge?