Why does filling loop have to be installed to the return pipe?

[Azz]

Hi all Im a gsr and just after clarification into this,as genrally manufatures state to install on return pipe of boilers.
Im only asking for advise, as a senior gsr said to me that its best to install on the flow side as when flushing the system connecting to the filter, it helps filling water on the flow side and draining from the magnaclense? This would help putting fresh water in system to completly drain any chemicals and dirty water when using magnacleanse.
I kind of understand the logic but what are your thoughts and would it void manufacturers warranty?

 

[ShaunCorbs]

It doesn't matter but normally the return is closest the water mains

 

[SimonG]

I was always under the impression it's on the return as its cooler. Same with expansion vessels.

 

[Last Plumber]

It doesn't matter where you put it and no, it will not invalidate a warranty.
If you look at vaillant ecotec plus Boilers, their built in loop is on the flow.
There are thing that are better placed on the flow such as filters and expansion vessels.

 

[Rob Foster]

It was an old convention as the return was considered to be cooler , so pump etc went here
Is stupid as once a boiler is modulating that concept is out if the window. Now insisting that inflow goes in the flow from the boiler is very sensible, and filters should go in the return to collect the crap before the boiler ..stuck on M6 ...off we go again uck. Centralheatking

 

[Azz]

I really appreciate the response from you guys.
Was wondering can anyone add me on the gsr forum
Thanks

 

[SimonG]

Oil boilers dont modulate.

 

[Rob Foster]

Oil boilers dont modulate.

Ok , not really involved in stink pots always Been a gas man or
Solid fuel Chking

 

[Riley]

I really appreciate the response from you guys.
Was wondering can anyone add me on the gsr forum
Thanks

@ShaunCorbs

 

[ShaunCorbs]

I really appreciate the response from you guys.
Was wondering can anyone add me on the gsr forum
Thanks

Pm me your gas safe reg and get a few more posts eg 10 total

 

[Sharp Point]

Oil boilers dont modulate.

Oil condensing boiler | modulating oil boiler | ROTEX

 

[Scott_D]

Filling loop on the flow
Drain off on the return
Shut boiler valves and mains flush through the system

 

[Aire]

Filling loop on the flow
Drain off on the return
Shut boiler valves and mains flush through the system

I was fitting a bathroom at a property where the customer had also got a local heating firm in to flush the heating. Guys turned up with a flush machine which they left in the kitchen, didn't even attempt to turn it on, they attached a hose to the drain off and opened the filling loop until it ran clear then proudly explained to the customer how clean the system now was and shouldn't have anymore issues, needless to say the flush wasn't exactly successful, I don't know why but I didn't have the heart to tell her she'd been ripped off

 

[Best]

I was fitting a bathroom at a property where the customer had also got a local heating firm in to flush the heating. Guys turned up with a flush machine which they left in the kitchen, didn't even attempt to turn it on, they attached a hose to the drain off and opened the filling loop until it ran clear then proudly explained to the customer how clean the system now was and shouldn't have anymore issues, needless to say the flush wasn't exactly successful, I don't know why but I didn't have the heart to tell her she'd been ripped off

If they charged her for a power flush I would have been fuming.