Balancing Rads

[NewhouseOldhouse]

Hi

I have been reading online articles and watching youtube videos on how to balance radiators.

few questions;
1. My new rads at min the 1st one in the line is pumping hot and the other 4 have heat coming in via the TRV but radiator not heating and lockshield side cold, could this be a balancing issue? does sound like it
2. All articles suggest taking the temp of pipes (flow pipe should be 12 degrees lower than return pipe) what temp should flow pipe be?

I have ordered these from Amazon so i can attempt to have a go this weekend.

 

[NewhouseOldhouse]

This is the new boiler that as installed 12 months ago and just reading that temp between flow/return should be 20 degrees as its a condensing boiler is this correct?

 

[terryplumb]

Are all 5 rads brand new and recently fitted ?
Are there other rads besides these ?

 

[NewhouseOldhouse]

Are all 5 rads brand new and recently fitted ?
Are there other rads besides these ?

yeah 5 rads are all new with 15mm piping going across loft then flow down to rads and return back up.

no some rads are on 8mm microbore but its a Bungalow so rads spreadout

 

[Ltnman]

I found for me it was impossible to achieve a 20C drop. I settled for 12C in the end as the bottom half of the radiators stayed cold with a 20C drop. Now the tops are very warm while the bottoms are cool but not cold. After a new boiler install and a magnaclean my rads were all over the place after I used a contact thermometer to set them up in the first place.

This time, I once again opened up all the TRV’s to 5. After the heating was switch on I just noted the order they heated up. I then turned all the lockshields to off opening up the hottest first by a quarter turn with the rest at half a turn. Over the days and with time on my hands they now all heat up at the same rate. My new boiler also shows the return temperature so I didn’t bother with the contact thermometer in the end.

Once happy adjust the TRV to personal requirement.

 

[oldbuffer]

1. Flow should be hotter than return, not the other way round.
2. Temperature difference should be:
2a. 20 degrees for a condensing boiler provided radiators have been sized and installed for this difference.
2b. 10 to 12 degrees for a non-condensing boiler, or for a condensing boiler with a system correctly sized for a non-condensing one.
3. Your radiators sound as if they are fitted on "drops", the term used for pipework coming from and returning to the floor above..
4. Radiators on drops are notorious for getting airlocks which cannot necessarily be removed by bleeding radiators.
5. I would suggest your approach should be:
5a. Make sure all TRVs are open. Set them all to maximum and see if this makes a difference.
5b. Ensure all air is out of the system. You might have to reverse fill with mains water but be careful not to cause a flood.
5c. If still not right, try rebalancing.

 

[terryplumb]

Is the pipework to the 5 rads new also ?
If not ,close EVERY rads TRV ,except one of the rads that doesn't heat up. See if it heats fully. If it does move onto the next problem rad and open it's TRV , repeat across all rads.

 

[Ltnman]

Forgot to add, the important thing is getting the return temp as low as possible if you want the boiler to condense more. The lower the flow the lower the return. For me the boiler is set to 50C. If the house remains too cool just turn up the boiler, as that will maintain the drop access the rads.

 

[NewhouseOldhouse]

1. Flow should be hotter than return, not the other way round.

yes said that the wrong way

2. Temperature difference should be:
2a. 20 degrees for a condensing boiler provided radiators have been sized and installed for this difference.
2b. 10 to 12 degrees for a non-condensing boiler, or for a condensing boiler with a system correctly sized for a non-condensing one.

OK

3. Your radiators sound as if they are fitted on "drops", the term used for pipework coming from and returning to the floor above..

yes

4. Radiators on drops are notorious for getting airlocks which cannot necessarily be removed by bleeding radiators.

Flamco Valves installed throughout the heat system

5. I would suggest your approach should be:
5a. Make sure all TRVs are open. Set them all to maximum and see if this makes a difference.
5b. Ensure all air is out of the system. You might have to reverse fill with mains water but be careful not to cause a flood.

5c. If still not right, try rebalancing.

will try that thanks

 

[NewhouseOldhouse]

Is the pipework to the 5 rads new also ?

yes all new 15mm pipework with Flamco Valves installed on flow/return.

If not ,close EVERY rads TRV ,except one of the rads that doesn't heat up. See if it heats fully. If it does move onto the next problem rad and open it's TRV , repeat across all rads.

not all rads have TRV the 8mm microbore have the twin connector at one end but I can turn these down as well.

 

[terryplumb]

Flamco make a whole range of valves, which specifically are you referring to ?
Turn off all rads including the ones piped in 8 mm

 

[NewhouseOldhouse]

Flamco make a whole range of valves, which specifically are you referring to ?
Turn off all rads including the ones piped in 8 mm

this is the Flamco valves

will I turn 8mm rads off after I put heating on to see which rads heat first to start balancing?

 

[terryplumb]

Yes ,close valves/ TRV 's before putting heating on.

 

[NewhouseOldhouse]

Yes ,close valves/ TRV 's before putting heating on.

So I close 8mm rads but open 15mm ones to find out which ones heat first?

 

[terryplumb]

Close all the rads , except one of those that do not currently heat.
So only that one rad should now heat fully.