Adding MagnaClean To Flow - Two Pipes On Return

[Madrab]

We were always taught boiler then the Vent/Feed & pump with the horizontal (of the 'H' of the F&V) a max of 150mm between each other if not using an air separator. If that wasn't possible then the pump should be after the F&V as close as possible to it avoiding it being more than half way around the system & before the boiler. Single pipe systems are also notoriously sensitive to component placement.

If using a combined F&V in a domestic setup then we were always told to use the vent which was normally the same size as the main system pipe size, invariably 22mm.

 

[JackK]

We were always taught boiler then the Vent/Feed & pump with the horizontal (of the 'H' of the F&V) a max of 150mm between each other if not using an air separator. If that wasn't possible then the pump should be after the F&V as close as possible to it avoiding it being more than half way around the system & before the boiler. Single pipe systems are also notoriously sensitive to component placement.

If using a combined F&V in a domestic setup then we were always told to use the vent which was normally the same size as the main system pipe size, invariably 22mm.

That would mean that all pumps go on the return if your explanation was correct - What normally happens though is that they are on the flow

 

[fixitflav]

That would mean that all pumps go on the return

I don't see how you conclude that from "....boiler then the Vent/Feed & pump.....".
Maybe clearer to say "....boiler then the Vent/Feed & pump, then the rads...".

 

[DP]

Looked at the picture OP posted. Strongly suspect not a one pipe installation.
Latest drawing posted also not making sense

 

[DP]

That would mean that all pumps go on the return if your explanation was correct - What normally happens though is that they are on the flow

Jack, you pump is on the return, accept it
You will find you have two pipes running round your house, one is flow and other return, not a single pipe that each radiator sits on ( would be normal to have inlet at high tapping and return water at low point. Both radiator connections to single pipe for one pipe system.

Keeping an eye on the vent, get someone to switch on one zone or the other and different permutations. You should not get any discharge from the vent pipe

Would be prudent to employ a good heating engineer to resolve the issues.

 

[JackK]

I definitely have a one pipe system - I am sure of this and confirmed by many engineers - It is 2 inch steel pipework..

Heating engineers have advised replace all with new pipework.

I have one flor from boiler which then tees off for hot water at airing cupboard and continues up into the loft

 

[Madrab]

Looked at the picture OP posted. Strongly suspect not a one pipe installation.
Latest drawing posted also not making sense

Yup, it's all getting a bit confusing. There was a mention in there about brown hot water too I think, that wasn't answered.

That would mean that all pumps go on the return if your explanation was correct

Nope, it all depends on how the system is orientated, what is positioned where and how things have been set up, that's where it becomes really difficult to offer proper suggestions on an internet forum and not being on site to 'see' how it's all been laid out.

I think, as suggested, if DIY'ing you want to leave things the way they are. My advice would be the mag filter goes on the return from the rads (if that other return is the primary) and then add a cleaner, empty and flush your whole system a few times and then inhibit it correctly. Alternatively, re-pipe that section so there is enough pipe on the return at the boiler to fit the filter. Or, again as suggested, get a good CH engineer in to survey and sort out your system.

 

[JackK]

Here is picture again. I am sorry for confusion

100% one pipe system.

 

[Madrab]

Lets go back to basics and the first pic ..... there are 2 returns, one running along the bottom with the drain on it, that then runs up and onto the same return pipe coming down into the pump. Is one of the primary return (from the HW cylinder) and is the other from the rads?

Are you able to alter pipework?

 

[JackK]

Lets go back to basics and the first pic ..... there are 2 returns, one running along the bottom with the drain on it, that then runs up and onto the same return pipe coming down into the pump. Is one of the primary return (from the HW cylinder) and is the other from the rads?

Are you able to alter pipework?

Hi

Yes one return from cylinder and one from radiators. There is one flow out of boiler

I can alter the pipe work only in that space as the rest is steel pipes and can’t be cut easily

 

[fixitflav]

Hi

Yes one return from cylinder and one from radiators. There is one flow out of boiler

I can alter the pipe work only in that space as the rest is steel pipes and can’t be cut easily

I think it's time we hired a char-a-banc and arranged a visit by a posse of DIYnot-ers. Then we might get to the bottom of it.

 

[Madrab]

Which on is which? If the lower one is the primary return which I am guessing it may be as it's the last return on the pipe then OK, so to solve your original problem ......

As was suggested at the start, take that lower return and tee it into the vertical return pipe higher up, then re-pipe down to the pump location to give you enough pipe to cut in the filter & then fit the new pump below it and then hook back into the boiler return pipe.

 

[JackK]

Here is an annotated picture of the boiler. It’s a simple heat only boiler

Where should the magnavlean go

 

[DP]

Here is an annotated picture of the boiler. It’s a simple heat only boiler

Where should the magnavlean go

View attachment 303150

Read what Rab wrote and others too. I suggested return from the radiators.

Without sounding rude, i Am wondering if you will be able to carry out the task of installing the mag filter on the correct pipe. This feeling is based on what you have posted over 4 pages.

BTW, a blind man and his dog would have realised what boiler you have and what pipes went where.

 

[fixitflav]

what you have posted over 4 pages.

Not just these 4 pages. JackK has started about 6 threads over past few weeks where various aspects have been discussed. Nothing wrong with that, but reading them might give a fuller picture.