Balancing Rads on sealed system

[Dee]

While I wait on a dodgy company to resolve a dodgy shower door I've decided to try and balance my CH system. I have searched this forum but most discussions seem to be for UFH, heat pumps ect not so much for conventional setups.

I know how to balance but my question is....if I totally shut down rads on both the TRV and LS does this then unbalance the system and i have to do it again the following autumn? 

I have a large house so most rooms are shut up for the winter and I shut all those rads off ...is this correct?

Edited November 24, 2023 by Dee

[markc]

Don’t isolate rads during winter, turn the try’s down to a minimum but keep some circulation to prevent blockages. I’m not a plumber and others on here could say the opposite but on hydraulic systems we like to keep some flow.

[billt]

1 hour ago, Dee said:

I know how to balance but my question is....if I totally shut down rads on both the TRV and LS does this then unbalance the system and i have to do it again the following autumn?

 

No. You balance the radiators with the TRVs removed or fully open. Once the lock shields have been adjusted the system shouldn't need rebalancing. You can shutdown radiators with the TRVs with impunity.

[marshian]

6 hours ago, Dee said:

I know how to balance but my question is....if I totally shut down rads on both the TRV and LS does this then unbalance the system and i have to do it again the following autumn? 

I have a large house so most rooms are shut up for the winter and I shut all those rads off ...is this correct?

Why would you turn the lockshields down unless it's to remove the radiator

 

If the system is balanced and you need to remove a rad so close the LS - count the turns to close and note it down so you can restore it when the rad is refitted

 

If you don't want to heat all rooms in the winter turn the TRV down to the frost setting - leave the LS alone

 

No flow at one end is no flow thro the rad

[Dee]

I'm going to balance the (baxi 400/heatrea sadia) heating system tomorrow but I have a few questions....

 

There are 19 rads so how critical is it to adjust each rad in the correct order? I simply can't around them all fast enough to jot down the order/speed they heat and some seem to heat up at the same time.

 

The pump is set to 3 is this correct?

 

I'll be using a multimeter with a clamp, any tips or advice?

[JohnMo]

Go on Heat Geek they have a good write up what you are doing and why.

 

Do you need to do it fully or just a bit of fine tune?

[Dee]

I'm doing the full balance.  I've added a rad and turned 9 rads off by the trv completely ( not touched the LSVs ) as those rooms are shut off in the winter and the remaining 10 have all gone to pot! I don't understand why though. Some are now stone cold whereas before they were fine.

[Dee]

Read through heat geek and it's way beyond my comprehension. DeltaTs, emmiters, the correct LSVs.....!

I'm stuck with the system I have...a new baxi 400 and 24yr old pump, rads and valves. 

 

[JohnMo]

5 hours ago, Dee said:

and it's way beyond my comprehension. DeltaTs, emmiters

Emitters in your case is radiators.

 

DeltaT is difference between two temperatures. This could be room to radiator difference or difference between flow and return temps from boiler.

 

 

 

[Dee]

Thanks for explaining!

Hg says focus on room temp not rad temp but how do I measure room temp?

I think I'll have to do it the laborious way via the LS, I don't know another way 

 

[JohnMo]

7 minutes ago, Dee said:

how do I measure room temp?

Either with a room thermostat 

Or some of these

 

https://amzn.eu/d/e7oX9LZ, cheap on one day delivery, so you could have them tomorrow.

[Dee]

The link doesn't work I'm afraid. 

My first time balancing thie system with the new boiler and the flow at the boiler is 56c and Return is 46c.( It's a system boiler) should it be 20c difference?

Since starting from scratch this morning, the average across the rads F and R is average of only 6 degrees and some downstairs rads are now stone cold. All LSVs are only open 1/4 turn too. What does this tell me?

[MrPotts]

If the radiators were getting hot before then leave their LS alone and adjust the new radiator LS only.

[JohnMo]

3 hours ago, Dee said:

boiler and the flow at the boiler is 56c and Return is 46c.( It's a system boiler) should it be 20c difference?

Not always. Lower the flow temp the lower the dT.