Old cast iron column radiators flow return-urgent help

[Unregistered]

Hi there

I wondered if anyone could help quite urgently as rads get piped in tomorrow and I have a lot of conflicting advice.

We are restoring an old property at the moment which had no central heating. We are putting in modern combi and old reclaimed cast iron column radiators. Some are quite large. We are using these valves

Premier Traditional Angled Radiator Valves | Satin Nickel | Online Now

Some rads have

inlet at top/ outlet at bottom-opposite ends

inlet at top and outlet at bottom-same end

We were going to pipe: flow in at bottom and return at top as we were told the hold water would rise to the return?

I have since read that putting flow at top is best as water cools it will fall to return? Felling really confused?

I also read that bottom to bottom is ok for flow and return? Aesthetically would prefer this and would avoid us having to plaster in pipes chased in channel for top? Would this be ok if we balance the rads properly. Flow is in 22mm branched in 15mm just before each rad.

Just want uniform heat across the rads? Do you think if we do bottom to bottom and restrict return they will have time to get hot on all the sections?

Any advice very much appreciated
Elli

 

[village idiot]

Welcome. If you can try and register with the Forum, then chances are someone may help with the issues you have!!!!

 

[SimonG]

Tboe.

 

[Elli]

Now registered

 

[SimonG]

Top Bottom Opposite End

Flow to top and return to bottom

Oh and welcome to the forum

 

[village idiot]

Top (flow) bottom (return) is ok. If you can do the flow and return at bottom, that's also ok.

 

[Elli]

Thanks Simon-so would bottom -bottom not work do you think?

 

[Elli]

Ok so if I did bottom-bottom and just switched the blanking fittings to top that should be okay? Would I have to try and balance red to get uniform heat?

 

[Elli]

This is a pic of one of the bigger radiators

 

[SimonG]

Bottom and bottom is fine. If you can get the blanking plugs out!

 

[SimonG]

Have they been pressure tested?

 

[Elli]

Ok great-got Dad's big wrench and a very big piece of steel pipe-stubborn but strangely rewarding when they budge

Thanks for all your help!

 

[Elli]

Not yet-but have come out of old school/ some out of old house. Keeping my fingers crossed all will be ok. We flushed them with hose.

 

[Elli]

Thanks for replies everyone-will go with the bottom-bottom

Elli

 

[WaterTight]

strangely rewarding when they budge

Isn't it though!

Like popping a million bubble-wrap bubbles at once.

 

[ShaunCorbs]

how big is the property (how many bathrooms)

 

[village idiot]

how big is the property (how many bathrooms)

??? Are we on the same topic Shaun?

 

[ShaunCorbs]

??? Are we on the same topic Shaun?

just a bit of a left turn but normally property that are able to handle cast iron rads tend to be big just questing why the op went with a combi thats all vi

 

[oz-plumber]

A problem you may encounter is that the end fittings have left & right hand threads.

Rads that have the connections on the same side, you will not be able to swap to the other end because the directions of the threads will be different.

Have you any spare gaskets? You may need some if you are removing end fittings

 

[jtsplumbing]

They look a bit rough, wonder how much rust is inside them?

 

[rpm]

Have they been pressure tested?

I would do this first before going through everything else then finding leaks.

 

[stevetheplumber]

top botton opposite ends will give more output

 

[WHPES]

Would definitely say top flow bottom out for cast iron. Don't pipe both at the bottom. Any plumber worth his salt can make it neat by putting bends in the pipe to discretely drop it down behind the edge of the radiator.

Don't do bottom in, bottom out on cast iron.

 

[chris watkins]

These rads are not designed to work at 3 bar pressure which is the safety valve setting on your combi.
They have spent there lives so far in open vented systems with a head pressure of a floor or two i.e. 0.6 - 1bar.

If I were you I would be testing them first as SimonG suggested, then I would fit a safety valve with a lower setting to the system!

BTW - TBOE for the con's

 

[ShaunCorbs]

These rads are not designed to work at 3 bar pressure which is the safety valve setting on your combi.
They have spent there lives so far in open vented systems with a head pressure of a floor or two i.e. 0.6 - 1bar.

If I were you I would be testing them first as SimonG suggested, then I would fit a safety valve with a lower setting to the system!

BTW - TBOE for the con's

or run it on its own plate heat exchanger