Radiator Sludge

It's plumbing basics, the flow should go to the top of the radiator in your situation.

I’m not questioning the plumbing aspect.

In an earlier post, someone else advised me to go to local plumbers merchant, get their recommendation. Seemed good advice. That’s precisely what I did. That recommended guy has written “as you know a flush might help the situation”, confirming what he said on phone. I’ll give him credit for the “might”, the 2 other guys, who have both physically been in the property, said the powerflush WOULD help with much more certainty. Neither identified any flow/return confusion.

Guy today has the SAME info/images as shared here. Exactly the same. I’ve told him the gist of what’s in this thread. He says it’s irrelevant, dismissively, as the TRV is bidirectional.

Don’t you see my dilemma/position? I’ve not enough knowledge, what we call in IT the relevant SME, to judge if this or that course of action is wise. So I ask a few local “professionals”, and in this forum. I get, at best reading, mixed & contradictory advice. Not a little bit contradictory, but polar opposite contradictory. Eg try to square:

“flow/return connectivity isn’t relevant”

with

“It’s plumbing basics”.
 
IMG_5123.jpeg


That’s the before picture, the previous Volkera Compact 24 Boiler. All 6 pipes went straight down vertically under the floor. All were cut above floor level and rerouted to the new boiler. I’ve fotos of the “after” so I should be able to map those 6 pipes to the current connections on the new boiler. Establish if flow/return were inadvertently “swapped” by the Baxi installer. Unfortunately there is now an integrated oven / microwave / kitchen unit where the old boiler was, or else I could just look.

The after picture.

IMG_5124.jpeg
 
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Volkera - left two pipes are return and flow, respectively.

Baxi: leftmost pipe is flow, rightmost pipe is return.

WRONG.
 
He says it’s irrelevant, dismissively, as the TRV is bidirectional.
It has nothing to do with the valves, they are irrelevant. It only confirms your new plumbers misunderstanding.

The flow should go to the top, look it up if you like.
 
Volkera - left two pipes are return and flow, respectively.

Baxi: leftmost pipe is flow, rightmost pipe is return.

WRONG.

Yes, this seems to my conclusion too. Here’s my logic:

The left most pipe in the Baxi 430 Combi right now is the CH Flow, both from the product documentation and simple physical check - when it starts up that pipe gets hot first.

That leftmost pipe was also the leftmost pipe when the Volkera was in use, easily seen in the foto..

But from Volkera Compact 24 documentation that looks like it was the Return.

So despite my scepticism , it looks like the Baxi installer DID mix up flow/return. And it was connected “correctly” for the 15+ years before, with the Volkera, meaning the flow at the radiator end was at the TRV (top left) on all the radiators where the TRV is at top and lock shield connection at bottom. Which is all bar one of them. The exception is the radiator that works well, both connections are at bottom.

And the Gas Safe inspector didn’t notice, because he didn’t consider the radiators at all, just didn’t check flow/return.

That logic make sense?

Given the Gas Safe report from original Baxi installation, which rather soured the relationship, I don’t really know how to best proceed.

The guy I was recommended by local plumbers merchant insists that flow/return wrong way round is a non issue. My understanding is he’s plain wrong on that. Maybe he’s misunderstood my explanation? But he’s seem same images as shared here. Is that enough to just “walk away”, and find someone else ? If so, should I just tell the someone else I want flow/return swapped around, and not do what I’ve been doing which is describe the problem I am seeing ?
 
The guy I was recommended by local plumbers merchant insists that flow/return wrong way round is a non issue. My understanding is he’s plain wrong on that. Maybe he’s misunderstood my explanation? But he’s seem same images as shared here. Is that enough to just “walk away”, and find someone else ? If so, should I just tell the someone else I want flow/return swapped around, and not do what I’ve been doing which is describe the problem I am seeing ?

Have a chat with him.
We all get stuff wrong sometimes.

Valves may be bi-directional but radiators that are piped up TBOE are not!

To the remote eye, it's fairly obvious what the elephant in the room is.

For the sake of a couple hrs work change the boiler F&R round and see what the results are.

Gas Safe inspector is only concerned with "Gas Safety"!
 
Don’t you see my dilemma/position? I’ve not enough knowledge, what we call in IT the relevant SME, to judge if this or that course of action is wise. So I ask a few local “professionals”, and in this forum. I get, at best reading, mixed & contradictory advice. Not a little bit contradictory, but polar opposite contradictory. Eg try to square:

To put it in your terms - you have a software program listing printout, which is hidden under a sheet of paper. You/we know the input, you know the output, but you have absolutely no idea, what is happening in between. That's where the forum members are with your heating system are, and to some extent, that is the position of any plumbers you invite, until they have the opportunity to physically investigate.

All the forum members can do, from a distance, is make suggestions to form a list of thing for >you< to check out, and verify yourself, or to employ someone to do the checks, on your behalf..
 
Thanks. I’m actually active on helping people on a few IT forums, and it’s exactly the same - if I could see their screen for 10 minutes the problem would be often teadily identified. But of course they describe the inputs and outputs they get from what is effectively a black box to them, and you need to try figure out what’s actually going on via somewhat tortuous sequence of Q&As.

I therefore thank everyone for their input and persistence. I’m now really confident a previous hidden/unidentified core issue is identified. So somehow or other I’ll get flow/return swapped and only then consider the radiator performance topic. I’ve learned a lot. Thanks again.
 
I don’t really know how to best proceed.

Swap the pipes around near the boiler.

should I just tell the someone else I want flow/return swapped around

Yes. If they ask why, show them the connection diagrams for the old and new boilers. If they say “but it doesn’t matter, the valves are bidirectional”, tell them the rads are connected TBOE. If they still don’t get it, say “look do you want this easy job or not?”.
 
Looks like they forgot to install a filter

Well, there was no filter before and I didn’t ask for one. They quoted for supplying and installing (including relocating) the Baxi 430 combi boiler and fitting the new TRVs, and decommissioning old boiler. That’s what they did. Probably including the flow/return mistake.
 
Well, there was no filter before and I didn’t ask for one.
An inline filter has been mandatory since 2022 and required by the Building Regulations. The installers should have known that they didn't have a choice.
 

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