Radiator Plumbing Puzzle

[DIYDaz]

Can anyone help with some unusual plumbing I have found in our new house? A lot of effort seems to have been made to connect the flow and return to both ends of the radiator. I can't understand how this would work properly or why someone would do it. I'm an experienced DIYer and this doesn't make sense at all.
I'm thinking of changing it but thought there might be a good reason why this has been done.
Any advice or suggestions would be welcome.
I've tried to attach a picture which may explain the issue better.

 

[Chalked]

How old is your house? Before mid seventies? It could Be a one pipe system. If it is that's the correct way to pipe it up.

 

[DIYDaz]

Hi Chalked.
Thanks for your interest.
It's not an old house, 1983, but this radiator was a recent addition in the conservatory. It may be relevant that the boiler (an old Ideal Mexico) is just the other side of the wall.
I thought the flow may route back to the boiler via the copper pipe rather than going through the radiator?

 

[stevetheplumber]

looks like its piped one pipe for some reason is the pump at the boiler or up in the airing cupboad as rads need to be connected after the pump

 

[lame plumber]

one pipe system

 

[jonnyswamp]

As above, or a DIY bodge

 

[DIYDaz]

Pump is at the boiler. All other rads are plumbed in the way I would normally expect.

 

[DIYDaz]

I thought it may be a DIY bodge but why would they go to such trouble to solder extra joints and connections. They also left barely enough room to attach the valves.

 

[Best]

At 1983 era, the system is unlikely to be one pipe, unless somehow the whole system was diy.
That rad has probably been put in by a diy person who thought the flow & return must be connected directly to each other. DIY is always a mess IMO

 

[ShaunCorbs]

easy way to sort without drain down for now put aAladdin EasyFit Isolator on the pipe that links the valves

 

[DIYDaz]

Thanks ShaunCorbs. Are you confirming that the set up is definitely wrong?

 

[ShaunCorbs]

Thanks ShaunCorbs. Are you confirming that the set up is definitely wrong?

Yes, as piped now your rad won't work very good as the water will short circuit and go down the return and not go through the rad

 

[stevetheplumber]

without seeing the rest of the system its hard to say the link pipe might be used as a bypass??? does the rad get hot and the rest of the system work? if yes leave it alone

 

[AlexGas]

One-pipe system
This works using a one-pipe run (a complete ring of pipework) with a flow and return from the boiler. The disadvantages of this system tend to outweigh the advantages, so they are no longer installed in domestic properties. However, as with full-gravity systems, you may come across them in older properties.

Advantages:

Lower installation cost compared to two-pipe system

Quicker to install

Lower maintenance costs

Disadvantages:

The radiators on the system pass cooler water back into the circuit, meaning that the rads at the end of the system are cooler.

The pump only forces water around the main circuit and not directly through the radiators. This means it is important to select radiators that allow minimum resistance to the flow of water.

The ‘flow’ side of the rad is usually installed at high level to improve circulation, creating additional unsightly pipework.

A leopard never change its spots... It was an old school plumber! :smile:

 

[JCSPLUMBING]

I've come across this fairly recently in an old pub I was working in. It was a two pipe system bar one radiator that was piped up this way. It was used as a bypass.

 

[DIYDaz]

Thanks.
I've had a closer look and will try and post a sketch of the system in detail but it appears to be the same as the pub you refer to. Can you explain what the bypass does as it doesn't seem right to me? It the hot water bypasses the rad it won't properly?

 

[stevetheplumber]

is the rad getting hot ?

 

[DIYDaz]

Not really but I have only just moved in and haven't tested properly yet. I believe that the dining room rad which is a similar distance from boiler and is plumbed in the more conventional way gets much hotter quicker.

 

[JCSPLUMBING]

The bottom pipe that connected flow and return was the bypass. It acted to form a circuit in a case that all the rads were switched off to protect the system. On closer look, yours seems a bit odd. Why not call in a fellow plumbing & heating engineer. He/she may be able to explain a bit further than we can in with one picture to go on.

 

[DIYDaz]

I think it must be a mistake as there is already a rad in the house without A TRV. The conservatory and this radiator was an addition so if a bypass like this was necessary then there wasn't one previously (unless it was removed).

 

[Sparkgap]

Modern rads don't like single pipe systems as they're too high resistance to get a flow through! If it's being used as a bypass I'd put in a proper auto bypass valve elsewhere and chop the link under the rad, or at least stick in a ballofix to shut it off.