CH install - New Rads not heating - Need your help please

OMG! You guys are amazing! (y) I've just followed your advise, i.e. closed the TRV's for all radiators, except the ones in the attic and they are now heating nicely! I assume from what you've told me, it's not an incorrect piping issue and I don't need to lift floorboards because it's actually a balancing issue? If so, what next?

Thanks so much!
 
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Air lock might be possible, but I've just remembered something which I think might be important. When the boiler was originally installed a few years ago, the plumber told me that it was overpowering for 8-9 radiators. He said that he's adjusted some settings to reduce the KW or something. Could this be the issue?

Or before messing about with the boiler, should I try balancing the system first to see if it's all in working order?
 
Balance the system. Its usually the main cause. There are step by step guides in the wiki. (y)
 
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Thanks for clarifying this guys.

I've had a look at the wiki. It looks quiet complex, especially Point.7 the boiler pump...not sure what to do.

The manual is here: https://www.vaillant.co.uk/download...tec-pro-24-28-installation-manual-1414773.pdf

Is Point.7 referring to Page 31 of the manual, i.e the Pump Speed Target Value?

Also Point 3 of instructions says remove TRV heads and then open all manual rad valves fully - Unless I'm getting it wrong, if I remove the TRV heads, how do I open the manual rad valves fully? Do I need to turn TRV heads to full before removing them?

Lastly my boiler is a vaillant ecotec 38kw -
 
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If the boiler heating power is set too much it can cause a slow warm up but this problem sounds nothing more than a balancing issue.
Air locks...in a sealed pressurised system..nah, the OP has not mentioned any topping up required.
 
Thanks for clarifying this guys.

I've had a look at the wiki. It looks quiet complex, especially Point.7 the boiler pump...not sure what to do.

The manual is here: https://www.vaillant.co.uk/download...tec-pro-24-28-installation-manual-1414773.pdf

Is Point.7 referring to Page 31 of the manual, i.e the Pump Speed Target Value?

Also Point 3 of instructions says remove TRV heads and then open all manual rad valves fully - Unless I'm getting it wrong, if I remove the TRV heads, how do I open the manual rad valves fully? Do I need to turn TRV heads to full before removing them?

Lastly my boiler is a vaillant ecotec 38kw -

Simplest method...
Take all TRV heads off and check pins all move freely up and down with sprung resistance. (belt & braces not absolutely necessary).
Close all lockshield (manual valves) & then open them 1/8-1/4 of a turn.
Turn the heating on.
Give it 15mins or so.
Go round the house and see which rads get as hot as you'd expect.
Any that haven't, open by another 1/8-1/4 turn.
Give it another 15mins.
Keep repeating process on any rads that haven't warmed up, until they are all at desired temp... Touch based.
 
Thanks dilalio - That's exactly what I needed and it's definitely much easier to do. Couple of things:
  • Before taking the TRV head off, do I need to set the TRV to maximum (value 5)?
  • Do I need to adjust the boiler as per wiki or shall I leave that alone for now?
 
Set them to 5...this reduces the tension on the sprung pin and makes them easier to remove.

Leave the boiler as is for now.
 
While you have TRV heads off, is a good chance to check that no pins are stuck.
 
Brilliant - Thanks for this. I'm waiting for little one to go nursery and I'll make a start in about 30-45mins.

Thanks so much again!
 
polesapart - Not sure if the title needs amending as it's still the job of a plumber to check and balance the system, but if it makes it easier to help others, then that's fine by me.

Okay I've followed dilalio's advice and so far:
  • The boiler is running, but it's really slow in bringing the temperature up (seems to keep pausing and then slowly climbing).
  • The boiler is set to 75C max and after 15 mins it's so far reached 60C.
  • The radiators are getting warm, but some are either still almost cold and some are warm, but it's patchy and not equal on the surface of the radiator.

Also I want to apologise as I made a mistake in advising of the boiler's make/model. It's actually a Vaillant Ecotec Plus 835. Sorry again.
 
Guys, ignore my previous post. Thanks to your help and devotion in helping me, my CH is now working great. I used my FLIR ONE thermal camera to check the temperature. The temperature does vary dependant on the radiator, but it ranges from 61C (Attic), to full 75C in some of the rooms.

The main thing for me is that the attic radiators are working, so thanks very much!

One thing I noticed is that the top edge of radiators was much more hotter than the rest of the radiator panel which was cooler by a few degrees. For example the attic shows as 61C at top few inches, but then the rest of panel is around 56-58C.
 
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