sealing cast iron rad

12 Sep 2007
Reaction score
Newcastle upon Tyne
United Kingdom
Hi there i have an old cast iron radiator that has now blistered around the fitting so under pressure it starts leaking, My question is is there anyway to seal this myself or do i need to take it somewhere?
Many thanks for help
Sponsored Links
What fitting, ? if you mean the bush then just fit a new gasket, if you mean the valve tail, re-make it with ptfe tape.


If you mean the bush one end could be left hand thread.

more info and a pic would be handy.
thanks for the reply and sorry i did not make it clear that it is the actual radiator that is blistered, so could i try maybe some rad weld or something?
Many thanks
If the radiator itself is leaking then the section will be cracked.

You can replace the section or if it's not an end with legs simply remove that section.

And if that sounds easy sorry it is for me as I have the tools to doitall, in a nutshell you have no chance but to get the experts in or replace the radiator
Sponsored Links
No radweld will not work on cast and neither will welding other than bronze and a very skilled welder.

To break the radiator down you need a TeeBar and a pair of 2ft stilsons.

Before you start though you need to post a pic of the radiator as the nipple will be different for the make and age of the radiator.

Hopefully it will be a threaded nipple one end left thread the other end right thread, as you undo it the rad comes apart, but you won't know which way it turns and it could be either way.

As I said a pic and show the air vent end and the leaky section.
do you know where i could get hold of a new 60mm nut for a cast iron rad i have as the one i have has an old pipe chewed up inside so i need to replace it?
lbhomesolutions said:
thanks for all your help i will send pics once i have tools.

Slow down and post the pic first, the tools are all different sizes

What 60mm nut, do you mean the nut that connects to the valve, if so include the valve in the pic
the 60mm valve is for another radiator i cannot include pics at the moment as i have just moved and have not yet turned up the charger yet!
But it is for a valve end on a fat chunky radiator and the width of the nut that connects to the valve is 60mm.
I bought a few cast iron rads to put in our property but they seem to have a few problems so i am just trying to get them mended.
Thanks for your replies
What size is the valve and the tail that screws into the radiator 1" at a guess.

If that is the case and the bush is 2" you will find it easier to remove the bush after heating around the edge first, and replacing that, reducing to the size of the new valve in one go 2" x 3/4" for example.

Have the rads got feet on the end sections.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links