BALANCING RADIATORS part 2 looking into the ways of balancing radiators and seeing if it works.

Which infra red temp gun do you use please Derek?

I think this demonstrates exactly why many heating engineers fit the system and do not bother to try and balance the system.

Thanks for posting. I've been checking my rads in my cold house and was amazed some had valves that weren't even open lol.

Pump speed too high. Trouble with modern combis with a 7m head pump. You need to adjust the pump speed first with all valves open. Honeywell Valencia TRV’s are also able to be balanced through a nut under the plastic TRV head. Top tip if you have towel radiators then use both valves to throttle them right down if they are wheel heads

Thanks 👍

'EYUP Derek, Gr8 pair of vidz. Would be nice to see a "real system" wrestled with to see what can be achieved.
Happy 22

Hey Derek,
you're the man. love your videos, plenty info and a good laugh.
QUESTION. I've got a W Bosch Oil 18/25kw Boiler Heatslave II with 7 rads. all my TRVs are fully open (5) and lockshields are open with no room stat. Flow set to 61deg. is this bad sh*t? it set ON three times a day for about 2 hours each time.

Great video. real life training. Please do a balancing radiators in a real house video, thanks

Thomas Bradwell

Thanks Derek

Hello, I am need of a heating engineer to trouble shoot my recently installed Veissmann boiler, I have had three veissmann installers who are giving opinions rating from its ok( when radiators aren’t working) to I need to spend £1800 to rectify the problem, how do I choose a competent engineer?

I preferred when pumps had 3 speeds . Because if i had a heating issue or radiator not getting warm , i could increase pump speed temporary. Or adjust pump for various reasons. It was just more user friendly.
When you said "The Return temperature is getting to high?" I always find myself up against Low Return Temperatures, when i measure temp directly on return pipe at boiler.
I'll be honest & i normally go all "Old School" & check temperature's by god old human hand. lol.
Drifting off subject, my Non contact thermometer from day 1, has always seemed inaccurate! TPI 368, it always seem's like the readings are far too low. So i mutter a few swear words under my breath & revert back to touch.
So when you mentioned the Return temp. getting high, did you take readings from return pipe at boiler or at radiator return pipe?
Thankyou for video, as i only started watching recently, so sorry about posting on a old video.

M new WB boiler is labelled e
ERP does that mean it has one of those pumps? The installer upgraded m old floor mounted CF 8000BTU Ideal E Type in a day and did not spend much time explaining the physics. M boiler booklet says set it to eco . So could I turn it turn or leave it at ECO. It is a system boiler so feed the hot water cylinder that needs to be 60 of course.

Great system design, keeping the toilets cold to stop loitering on the job ... 😂

... if all the radiators have trvs are you not in danger of stopping the flow completely whilst the boiler is on if the room stat is set high?

P.s. isn’t it easier to get a greater delta t the bigger the radiator is as it dissipates more heat from any given flow?

Great video Derek, Its nice to see an expert show how hard this can be in the real world!! I watched this to see if I could pick up any pointers as I need to do my home system... I found that 3 of the rads have the flow and return reverse connected. With the TRV on the return leg and a lock shield vlv on the flow. I am guessing I need to correct this but what are your thoughts please??

Great video, thanks Derek...

Brilliant Derek, thank you 👍 One point I picked up on is now we are required to have TRV,s on all rads and using weather comp why would there be a requirement fir a room stat ?

Do u not understand that you have to wait at least 5 minutes to see a change in the rad delta t??????

8 hours and ubdidnt tell us how to balance radiators! Well done.

Flow temp, Weather comp, range rating, room thermostat all nothing to do with balancing radiators!!!!! The size of the raditor in each room being too big for a room has nothing to do with balancing it!

Brilliant and an honest appraisal of what most engineers knew😂
So basically be careful if you don't use Lockshield valves be prepared for a lot of hard work to go out the window when the customers or decorators adjust them😂👌

Yes, please, I would like to see you try it on your house. This has been surprisingly exciting!!

Great stuff.
having just been round 21 radiators in this house trying to get that delta T. looking at the clouds forming above the flue from non condensing. I just realised that the HW (cylinder) was in the loop and shoring the boiler.
the override for my control turns all the diverter valves on..
some rads could get 20 Deg drop. most were about 6 and granted it could be colder outside.
the WB CDI 40 did a stonking job of throttling back to keep the flow of 60 for a fixed pump speed. set correctly in the setup though as it only measures the flow temp.
sadly it doesn't have external bus control. but I don't see the difference between the stat reducing the output as we approach setpoint, and the boiler reducing output as the return increases, as we reach setpoint.

anyway. it's a dark art and took about 3 hours. but the appliance consumed 50kwh of gas with the last hour down to a 12kwh burn.
I think close enough is good enough. I will check it again when it's colder outside and we need the heat.
great video, but there is a lot of science behind why we should do this, complicated by modulating devices.

I found this quite fascinating (yeah I know I'm a sad b******) the main thing I took from this is that no heating engineer or plumber is ever going to spend 8 hours doing it as he would be 8 hours @ £x's / hour more expensive than the cowboy competition, maybe a cursory walk round (on job completion) to see if the rads are 'hot' is probably the best you can hope for

is the DT20 based on a DOT of -3c similar to other areas of heating? Your heat loss per room will be based on that and in theory your rads sized for that. So your DT may only be 20 when your room heat loss is at DOT. If you’re at external temp of 10-12c your heat loss will be half so your DT will be much lower?

I have two radiators that isn’t getting hot flow in the same part of the house. I’ve messed with the lock shields but not really solved the problem. I’m interested in the thermostats on the radiators of which there are 5. I’m going to turn these off. Let’s see what happens cheers

Hi the video was very nice. I have tried all these in my house and i have come up at the same conclusion. About my set up i have a Vaillant ecoTEC Plus 838, 14 brand new radiators all of them brand new, and 22mm and 15mm pipes. i know all pipes distances which are from 12m the closest to the boiler up to 26m the longest on controlled by nest 2nd gen. All rad have TRVs. Flow temp 60 C return 54 C according to the boiler information. My problem is that the house warm up relatively slow (in my view), according to nest 1 degree every 30min and the longest rads take longer time to warm up. Off course when I close some TRVs everything speed up. I have come across 2 potential solutions. The first is to install external pump along with Low loss header and to fully open all valves or the second one is to buy Honeywell thermostat with digital TRVs to control the temp at every room. I know that they are not same approach. What do you think? What is your opinion. Thanks

Thank you

Think if you reworded the video it be more popular. "To how to save on money on heating by balancing radiators." In this heating crisis its definitely an avenue that engineer could offer the public.
My idea would be to see you do it in your own house. See the result and use dan Floss self balancing valve to see if the results were similar or better.

I've been in a ground floor flat of a Victorian construction house approx 1600 square feet with huge rooms and 3m high ceilings for 13 months now and I've had more success balancing radiator sizes and BTU requirements due to the explantions and clear content of your videos. Thankyou!
However, next year when we change the boiler and upgrade some very old rads the heating engineer is getting the Spanish Inquisition on efficiency and calculations. I apologise in advance to whomever it may be. 😁

I think the real problem here is the pump is effectually massively oversized for the system, but there's not really a lot you can do about it with a combi. The narrow delta T is because the water is moving around way too fast, and throttling the lockshields down so much will probably reduce the life of the pump.

You mentioned the pump being an issue initially with getting heat to all the radiators.
Now when throttling down each radiator in order to achieve a delta t, am I right that the pump will automatically slow down gradually, as you adjust each radiator ?.
Secondly, why is it necessary to allow the system to cool after each stage of the process ?.

Hi Derek I'm sorry but I didn't understand why you haven't range rated the boiler down to meet your system's needs...in my opinion the return was so close to the flow also because if the boiler is putting in too much heat for your system, the return starts to get closer to the flow because radiators can't dissipate the amount of energy they're receiving...the boiler begins to modulate down when it's approaching the flow temperature required but it could eventually come off if the minimum output is still too much...am i wrong? I'm a young apprentice trying to learn more

Would doing this work on an open vented system with a condensing boiler? Ive set it to 55c for water and heating because thats the only option available.

Ive managed to get most of my radiators to have a minimum of 10c across them, so what do i need to do with my pump? Its on the middle speed atm, do I speed it up or slow it down?

Excellent video. I hope everyone who wants to ‘balance’ radiators watches this first. I had just bought an IR thermometer and was going to look at balancing the system this afternoon. Thank goodness I watched this. I’m not going to waste my time with this procedure. 
I will ask what might be a couple of dumb questions? I think you are trying to balance to achieve the required temperature in each room. In which case why not rely on the TRV to do that for you? 
In that case do you want to adjust the lock shield to get the rate at which the radiators get warm to be approximately the same? Otherwise the rooms could reach the desired temperature at markedly different rates.

good info , proudly watch this again though lol balancing is like splitting the atom

Does anybody else notice Derek letting rip at 16.16 😂😂 Great Vid 👍

My boiler shows flow and return in the menu. Flow is set to 50C with the return at 35C. My 4 bedroom small detached house was built in 1990 and with your help I have all the radiators heating up evenly at the same time. They all do feel very cool at the bottoms of the rads and the house takes longer to warm up but even last winter when it was -8C outside the house still heated up.

In your video I don’t understand how you can have a radiator hotter than the flow temperature into it?

You can also listen to the slight noise that a valve will make when restricting flow. It helps finding a starting position.

My tips here: listen to the sound that the water makes when restricting the flow. It makes for a fine initial setpoint on the first rads.
Second, just let the heating run, and measure return temps only. If return is equal, (top of rad must of course be warm), you're good.

Over here, plumbers like to fit calibrated valves. Adjust to the radiator size and delta T will come out correctly.

It would be easier to balance the system if we went back fixed power pumps rather than the modulating pumps now in new boilers.

Hi, I missed it along the way, what did you set the trv's at on each rad please? ...the only radiator we have that does not have a trv is in the bathroom, and as you guessed, it gets very hot! ...great video

I watched these two videos then spent nearly two days balancing my radiators!
I knew that the plumbers who fitted my system couldn’t have balance it, they left too soon after filling the system.
I’d been experimenting with lowering the flow temperature and found that I couldn’t get the house comfortable with a flow temperature below 65 degrees.
Now it’s all balanced I’ve got the flow temperature set to 50 degrees and the wife hasn’t noticed 😀
The maximum flow temperature I’ve seen at a radiator is 41 degrees. So now I have to go into the loft and find where the spare ten degrees is going. 🤔 (I live in a bungalow and all the central heating pipes are up there.)

I have a condensing boiler but the pump is not an ERP pump how do I work out the flow and return temp drop do I observe the temperature and adjust the pump speed ?

Why so many boilers

My house has a Vaillant 12kw system boiler and full smart controls and works just fine with a flow temperature of 45c.
25 radiators 3640 ft sq. 2 zone plus HW.

Spot on and do another one sir😊

You said you left 1 rad fully open is this so the pump doesn’t get damaged?