Adding MagnaClean To Flow - Two Pipes On Return

[DP]

My FandE tank and vent is in the middle of a system - I would think most homes have this setup - My pump is on the return at the moment

How is it the case that most homes have pumps on flow and therefore option 1

Don’t understand Jack.
F&E cistern would be located at the highest point else it could not serve the purpose it is installed for

 

[JackK]

Here is a diagram of the current boiler layout

Can I move the pump to the floor slide

 

[Johntheo5]

THe F&E tank cold water in is via a ballcock, is this what you mean?.

 

[denso13]

THe F&E tank cold water in is via a ballcock

Which makes it a cistern, not a tank!

 

[Johntheo5]

A rose by any other name, a cold water storage tank, CWST, has a ballcock, have never seen it called a cold water storage cistern, CWSC??

 

[denso13]

have never seen it called a cold water storage cistern, CWSC??

Water Regs UK Limited Cold water storage cisterns

Specific Installation Guidance General Cold water storage cisterns If the installation a storage cistern is notifiable , under regulation 5 of the water fittings

www.waterregsuk.co.uk

Sorry, hammered in to me at a young age, apprenticeship, It's a cistern. And the only time you can get a rising main is when it goes up a hill!

 

[JackK]

Just to be clear I have a seperate Cold water storage tank - The fande is for heating system only - It has a ballcock

The location of the fande in the diagram is for both mains water coming into the fande tank as well as how the system is filled - The system is filled at the highest ppoint in the loft from the FandE

 

[Madrab]

A rose by any other name, a cold water storage tank, CWST, has a ballcock, have never seen it called a cold water storage cistern, CWSC??

I have always called them a Cold Water Storage Cistern (CWSC), just like say a cistern for a toilet.

In plumbing, I was always taught that a tank was defined as a closed/sealed vessel for storing liquids, typically fed directly by a pipe, a cistern was an open topped/unsealed vessel that typically comes with a removable lid/top fed by a ball valve with an air gap. used to get a slap over the head when I called it a tank, oh happy days

 

[JackK]

Any advice on pump position given the layout of cold water coming into the system

 

[Johntheo5]

Sorry Jack, but I'm still confused.
Normally, one has, as you say, a CWST and F&E tank but both have their own filling ballcocks fed from the mains.

I have seen open vented systems where there is no vent from the system, with the cold water outlet to the system which is also the expansion pipe, there is also a overflow which is installed high up on the side of the tank. If yours is like this then it should, IMO work very similar to my combined cold feed and vent.

 

[Madrab]

Don't look at the drawing in relation to the flow and return, rather in relation to where the feed and vent (F&V)from the F&E cistern is located. That's why there isn't a boiler in the drawing. That's also why the pump can be anywhere on the system as long as the design principles are applied.

The pump location in relation to the F&V is to avoid the pump either pumping over through the vent or the air being drawn in through the vent, both increase system corrosion significantly.

It was always easiest to locate the pump in the airing cupboard below where the F&E cistern was usually located, that way the 'H' section ( the area that @DP mentions that tends to block up due to crud being caught) where the feed and vent join the system could be placed in the same space in the correct orientation and distance to/from the pump.

You also have a one pipe CH system, was that mentioned at the start, can't remember? You also didn't explain if you are getting brown water through your HW tap?

 

[Madrab]

If you only have one feed and no larger vent rising up and over the F&E cistern then it must be a combined F&V.

If the pump is on the system after the F&V on the return, then the system will be mostly under positive pressure > Fig3. The closer the pump gets to the F&V on the flow side of the pump, then more of the system gets into negative pressure as more of the positive pressure will find the path of least resistance which is usually back up the F&V, which isn't ideal, of course height/distance is very relative too

If the pump will only be moving forward by a small amount, in relation to the size/length of the system then the impact of that change should be minimal but without being onsite and actually seeing everything, it's never easy to be sure.

Also when changing certain system layouts, it can also be trial and error unless you can see everything or you installed it all, but it is much easier for a pro to correct any issues that may be introduced, as it's usually easier to alter.

 

[Johntheo5]

Something like this??.

 

[JackK]

Here is a clearer diagram

Any advice appreciated on pump position

 

[Johntheo5]

The vent should be before the cold water feed and the pump should be, IMO, be mounted close by. If the cold water feed is I think 22mm or greater then you can just blank off the vent but would need a air vent or two to help when filling the system.