Adding MagnaClean To Flow - Two Pipes On Return

[JackK]

Trying to get some wisdom from the forum elders here as I am doing bits and pieces around the house

I have an old boiler which I cannot afford to replace - It has one pipe from flow up behind some chimney and then two pipes return which are joined just before the green pump

With my June salary I will spend £140 to buy a new pump but for now I have bought a 28mm Magnaclean filter - I can only put it on the flow pipe from my thoughts - If anyone can suggest a better place on the return (which is where it should be) that would be very useful to know

If I put it on the return against the wall this will only cover part of the circut - What would you do - Magnaclean on single flow pipe or on part of the return

 

[Mottie]

I don’t think you need one. I’m no expert but when we had our system converted to a sealed system with vented hot water, we had a Potterton profile boiler which at the time was around 25 years old. They also changed the hot water cylinder, controls and the valves. I asked at the time whether it was worth putting a magnetic filter in at the same time and they said no, not with an old boiler with a cast iron heat exchanger but that I should think about getting one if I ever changed the boiler for a modern one. I did do that a few years later when we had a new boiler.

 

[Lower]

Re-pipe it so that the return join is further away from the pump so that you fit the filter in.

 

[roguetrader]

They are supposedly fitted to the return to protect the boiler, but no filter catches everything first pass, so especially with an older boiler, it really won't matter on the flow.

 

[DP]

If push comes to a shove, I would instal the filter on the radiator return pipe

 

[Madrab]

Why are you fitting a filter in the first place, is the system dirty, is there something that is driving you to fit one? Also, why are you replacing the pump?

CH and boilers worked perfectly well and stayed nice and clean long before MAG filters were even a thing. Is it open vent?

If the system is nice and clean and there are no circulation issues then I'd leave it well alone. if it is then the system is stable and conditioned. if you start to play around with things, draining etc then that's when you can start to introduce problems.

 

[JackK]

Why are you fitting a filter in the first place, is the system dirty, is there something that is driving you to fit one? Also, why are you replacing the pump?

CH and boilers worked perfectly well and stayed nice and clean long before MAG filters were even a thing. Is it open vent?

If the system is nice and clean and there are no circulation issues then I'd leave it well alone. if it is then the system is stable and conditioned. if you start to play around with things, draining etc then that's when you can start to introduce problems.

The system is filthy - Its an old floor standing boiler on one inch steel pipework and I cannot afford to replace the boiler at the moment - It is open vent

There are some circulation issues but each time I drain it for maintenance the water is black and brown

I thought sticking a magcleaner was the cheapest mainteance job I can do to prolong the life of the boiler - Am i mistaken ?

The pump is old and slightly noisy - Again easy to change - Is it not reccomended ?

 

[jeff the gasman]

You don’t need one !
Buy a pump and some inhibitor instead!
You’ll need new pump valves too!

 

[Madrab]

+1

new pump if there's circulation issues, good clean/drain and flush until it runs clean then properly inhibited. A mag filter at this stage may not add any benefit but if you have one then no reason not to fit it I guess.

As suggested, if you have no where else then the downward leg of the return pipework - which at a guess may be the rads with the other lower leg being the HW Cylinder?

 

[JackK]

Is it a crazy idea to move the pump to the flow and the put the filter at the return.

Or do you think it was installed this way for a reason

 

[jeff the gasman]

Is it a crazy idea to move the pump to the flow and the put the filter at the return.

Or do you think it was installed this way for a reason

It could give you a massive headache!
It would alter the hydraulic balance!

 

[DP]

Is it a crazy idea to move the pump to the flow and the put the filter at the return.

While may not be prudent here, why is pump fitted to flow a bad idea?

 

[DP]

Brown water- check if the vent is passing water ( pumpover).
If yes, correct the issue.

In support of what I posted, have In the past attended systems where large radiators with centre failing to heat were cured after Magnaclean filter was fitted

 

[JackK]

Brown water- check if the vent is passing water ( pumpover).

Could you provide some explanation on what you mean - The pump is from a heat only boiler to an indirect cylinder coil. The water from the boiler (which I actually suspect is being drawn to the hot tap) should never mix.

I do not believe it is rust from the pipe

Note that the kitchen tap is a mixer tap which I do not think is suitable for low pressure system - I did notice previously when I took the cylinder out that running cold water caused a back pressure on the hot water pipe (as I saw water coming out of the hot water vent

The FandE and cold water storage tanks have also been renewed and are new

Any ideas most appreciated

 

[DP]

Is your system open vented or a sealed system.
If the system is open vented, a small cistern (feed and expansion) will be placed at a high point in the installation

The cistern will most likely ( not always) have three pipes. Cold connection via float valve, a feed pipe at the base or just off the bottom which feeds water to the installation and lastly ( not counting the overflow) a pipe that loops on itself to have open end such that any issue from it will go into the cistern.

There are times when pipe restriction, bad plumbing etc will result in discharge from the open vent. As the water falls from the vent into the cistern water, it gets ’oxygenated’. End result is brown water. This issue often seen as a brown mark rear of buildings where a sealed system is pressurised far too often rather than rectify the cause

You mention the F&E has been replaced. Is there any discharge from the vent pipe when one Or the other zone is calling or both zone demands are on

I have not read every post on this thread, but you can get brown water from an unvented cylinder. This type of cylinder often is a metal cylinder ( some are glass lined) where the sacrificial anode has not been looked at and the jacket itself starts to rust resulting in brown water at the hot tap
Your cylinder is open vented.
I read that it has been replaced so unlikely the indirect coil will be perforated.
Back pressure as you mention, most likely cold water going back up the hot pipe if hot tap open or the shower mixer doing this.