Radiator problems

[abay710]

Hope someone can help.

I have recently moved into a new house, it's 15 years old and has a new boiler, but still the original radiators.

Since I moved in I have found that all but 1 radiator in the house are not heating up properly. They are all warm at the top but cold at the bottom. After doing some research many people were saying that this is normally caused by sludge. So I got a plumber out to do a powerflush, however before he started he said that wasn't the problem and didn't do it.

What he said was the problem was that the flow has been plumbed to one of the bottom corners of the radiators and the return is plumbed to the top, so he says that the water is coming in the bottom rushing to the top and going straight out and this is why the radiator is cold at the bottom. All the radiators in the house are like this, apart from the 1 radiator that is working fine which is plumbed both pipes to the bottom.

His advise was to adjust the plumbing at each radiator to bring the return from the top to the bottom, so that the flow and return are both at the bottom.

Can someone tell me if this would cause a problem with the return going out at the top. The evidence is there seen that the 1 working radiator is both plumbed to the bottom, but the house is 15 years only with 2 previous owners so find it strange that the people before had these problems for so long, and didn't do anything about it.

Also don't want the hassle of this extra pipe only to find it makes no difference.

Thanks for any help

 

[JohnD]

TBOE is one of the correct ways, but yours is going round the wrong way. Perhaps the pump was replaced the wrong way round, perhaps the boiler was changed and the installer missed it.

"flow has been plumbed to one of the bottom corners of the radiators and the return is plumbed to the top"

should be the other way.

BBOE is the most popular connection in UK, but TBOE is a bit more efficient, and I am told is compulsory in e.g. France.

You probably can't just reverse the pump, unless the flow is also going the wrong way round the boiler. Cutting and crossing over some pipes near the pump is probably needed.

see also http://eprints.hud.ac.uk/id/eprint/7416/1/400-Pillutla.pdf and search TBOE
It's a wordy document that explains something I thought was common knowledge. I'd have thought your plumber knew.

 

[abay710]

Thanks for your reply JohnD

So the house is 15 years old but the boiler has been changed a couple of years ago.

It is a combination boiler, is it more likely that the house is plumbed wrong or have the flow and return been mixed up when the new boiler was fitted?

Would it be as simple of swapping the flow and return over at the boiler to get the radiators to fill at top and return from bottom?

 

[JohnD]

possibly, but I'd have thought a competent heating engineer should be able to have a look and see what needs doing within about a minute.

I am not a heating engineer.

My guess is the boiler installers made a mistake and connected the old pipes wrong. I've seen it done (by professional heating engineers).

If you look up the installation instructions for your boiler it will show you which of the pipes is the radiator flow, and which the return. You have to pump it the right way through the boiler, or it will (probably) shut down.

If you feel the boiler pipes, the "flow" will be hotter than the "return". You can put arrows on with permanent marker to remind you, if you want.