rad going cold on bottom after flush out

S

snadge

im having lots of problems with the CH at moment...

this one is related to the rad that was cold on bottom and hot on top - i took it off and flushed it out and it worked ok but then i noticed after 1 hour the rad would cool down even when the CH is on full belt (its not temp met at wifi thermostat) - my dad says lockshield valves can do this and also im wondering if the TRV set at 5 stops it when its got to a certain temp (24'c?) - i was under the impression that 5 meant open full regardless of temp but im starting to question that due to other "happenings" with TRVs around the house...

thanks in advance...
 
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Close the locksheild, get the rest of the system hot and then open it a 1/4 turn at a time leaving 3 or 4 mins between adjustments.
 
Just noticed your other post, you need to balance your system as you have been altering the locksheilds.
 
Just noticed your other post, you need to balance your system as you have been altering the locksheilds.

this radiator done this before i took it off and its the ONLY radiator that ive touched... i will try what you said , thanks

edit: do you mean turning the valves on/off? (not the TRVs, the opposite valves ... is this what you mean by 'altering the lockshields')
 
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Yes, not the TRV's, you only need to concern yourself with the TRV's normally, if you close down the locksheild then no water can enter the radiator, so there is no point in closing the locksheild as it will make no difference. Also if you open a locksheild fully then the hot water will pass through the radiator too quick and wont have time to get hot.
 
Yes, not the TRV's, you only need to concern yourself with the TRV's normally, if you close down the locksheild then no water can enter the radiator, so there is no point in closing the locksheild as it will make no difference. Also if you open a locksheild fully then the hot water will pass through the radiator too quick and wont have time to get hot.

i dont currently have any lockshields half open and one the rads causing the noise havent been touched with lockshield... ie the bathrrom ive only ever altered the TRV - since doing that it started banging, ive since found out that TRVS upstairs are all on wrong ends... but the banging has just started getting bad these past few days when i did alter the lockshield on different rad upstairs... in the main bedroom i put the TRV (wrong way around) on 1.5 and the lockshield valve 3 half turns (10 hlaf turns was complete) in order to cause a slow flow of hot water cos the pipes are noisey due to expansion in that room - they must be fixed to timber under floorboards , but to also cut down on fuel consumption, we had all rads on so i turned 2 off and that one in main bedroom down to 1.5 and 3 half turns... its been SINCE then the banging started in the bathroom... bathroom lockshield has not been touched and is open full - it bangs on 5 ,4 - any setting so i have it off now

also, the rad thats getting cold after heating up is not water coming through because the return pipes are cold/colder too... so its either sludge still in it or the TRV restricting it... i think anyway... if it were hot water going through too fast the return would be hot yes?


thanks for your help
 

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