Radiators warm at top, cold at bottom - NEW SYSTEM !

Hello

I've red all posts related to subjected problem. I have the same problem on some rads. Why I'm writing again is because of following facts:
1. the worst problem is at rad which is the farthest from the boiler
2. the problem also has the rad which is - almost the closest to the bolier
3. the system is brand new (just second heating season)
4. all rads are vented (seems like this).
5. the worst rad has TRV (works properly). Lower (out) valve is opened 100%
6. when closed other rads, the situation was much better (almost OK)
7. I cannot reduce any rads on that branch from boiler !

I have tried to make balancing, but without success. I need to read carefuly about balancing and try to understand it.
The plumber cannot come to spend one day in balancing rads.

Any advice ?

Read the instructions in the FAQ on this site and get a thermometer so you can set the flow to give 15-20 C differential temperature across each rad ( assuming its a condensing boiler ).


Tony

Agile said:

Read the instructions in the FAQ on this site and get a thermometer so you can set the flow to give 15-20 C differential temperature across each rad ( assuming its a condensing boiler ).


Tony

Click to expand...

Sorry I'm new on this forum and don't see FAQ. Could you tell me where to find it.

Thanks Peter !

near the top of plumbing heating page 1, sticky FAQS

Found - Thanks. Read it !

Now, I will try the recommended suggestions.

But
I have already blooded that one rad (few times) - there is no air in it.

One more question related to balancing:

I have 3 main branches that go from boiler. One of them (the longest) has (at the end) the "problematic" rad.
My estimate about length is : 20 meters of pipes from boiler to the problematic rad.
That branch has 2 more rads (lets say 17 m far from boiler) and 1 more (small) rad just opposite to that problematic. In total: 4 rads on that branch. Mentioned 3 rads on the branch has no such problem (but they are opened 1/2).

Now, my question is: when I do balancing, have I need to close rads on all other main branches or I can do balancing only on "problematic" main branch ?

From the described, do you have some additional advice related to balancing.

Thanks Peter !

You have to balance the entire system.

For ease close all lockshields to being open just 1/2 turn before you start.

All the adjustment is in the first 1.5 turns.

Bleeding rads is ONLY needed when there is air in the rad AND when its cold at the top!

Tony

Thanks Tony

I'll try to do it on this weekend.

Only we have estimated 20 degrees outside temperature, so I'm not sure my boiler will run
I have entered this forum late

How to balance a CH system tells you how to do it, step by step.