Radiator problem

A

askew70

Registered User
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152
Hi,
I had a radiator fitted in my kitchen about 5 years ago. It is the same style as the following, but it is coated in white enamel:

[broken link removed]

Within a year or so, I noticed that there was a very small amount of water leaking from the nut at the top of one of the verticalside bars (the other side has the same nut, but does not leak), maybe a drop every now and then. The suppliers were not very helpful so I had a plumber look at it - he replaced the nut, and washer, but it never solved the problem. I thought I might undo the nut at some point, wrap the threads in tape (the thin white tape that I have seen used on threaded plumbing joints in the past), and re-install the nut, but I never got round to doing it.

More recently, the water dripping out has increased a little, and the water looks more rust coloured. When I examined it more closely this evening, I found that the top horizontal bar (which meets the vertical side bar just an inch or so from the leaking nut), has a crack in the enamel and it is as if the enamel is trying to peel back a little. I am not sure how long it has been like this, as the crack is towards the back of the bar and therefore out of view unless you climb a chair to have a look at it.

I am wondering whether the cracked enamel is an indication that the radiator is badly damaged and needs replacing, or whether it might just be sufficient to have the leak fixed once and for all (assuming it can be fixed) in the hope that any damage to the radiator will not get worse over time?

Thanks for any advice.
 
I'd imagine the rust and flaking paint is only superficial. Fix the weeping nut (PTFE and some Boss White should do the trick). You can buy white radiator paint in spray cans for touching up at Woodies.
 
Thanks for the advice Carpenter. Is PTFE the thin, flexible, white tape that I have seen plumbers use on pipe joints in the past? If so, would you recommend wrapping the PTFE round the thread of the nut first, and then applying Boss White over the tape?
 
Yes PTFE is that thin tape. Wrap the thread a couple of times and then rub on a bit of boss white, over the tape. This plug is presumably to vent the rad so you'll need to do this before you refit the plug.
 
Great! That leads to another question (and the main reason I have not got round to sorting the leak out to date): is it necessary to drain the radiator of water before removing that nut, or is there only likely to be a small/slow trickle of water that'll escape when I remove it (i.e. so little water that it won't go everywhere and make the nut hard to put back in)?
 
Here's my fix. Remove the plug, clean the thread and wrap with PTFE before screwing in slightly (not fully home). Run the boiler, as the water heats up air will be driven from the rad and when water starts to trickle from the vent screw home the plug fully. Your rad should now be air and leak free.
 
If the company that has sold you the radiator stated somewhere that their product was "enameled " than just let them deliver a new one. "Enamel" means glazed i.e. covered by a layer of silicate melted to the metal surface with the aid of heat, similar to the enameled bath tubs, in a kiln. What you are discribing as "peeling" does not seem to be enamel at all but ordinary paint work. A "breach of contract" could be the issue, in this case your consumer rights would be allowing for an unlimited come back. The usual sellers/manufacturers guarantee time of 2 years wouldn't be of any importance here.
Good luck.
 
I had a go at sealing the radiator this evening (using just PTFE, which I happen to have already, but no Boss White). Remembering to close off BOTH valves to the radiator would probably have saved me an unexpected shower (just the weather for a cold shower!), but on the plus side I won't be forgetting to do that again in a hurry.

I think I know what the real problem is now, and it probably dates back either to when the radiator was manufactured, or to when the plumber fitted it. It does seem to be enamel on the radiator (can't find the original product brochure yet unfortunately, but I plan to keep looking - the coating seems to be solid and brittle though, unlike what I would expect paint to be), but the quality of this coating, around the hole where the leaking nut sits, is poor. Basically, around the edge of that threaded hole, the enamel is a little uneven and cracked, and while I was re-fitting the nut a small piece broke away. The effect is that the nut is trying to mate with an uneven surface and so it seems impossible to get a proper seal between that surface and the rubber ring on the nut. Right now, no matter how much I tighten the nut, I can't seal it fully so a little water continues to seep out over time.

heinbloed, I would be very interested in pursuing this with the retailer based on what you say. The word "peeling" in my original post may be misleading. The enamel (assuming here still that it really is enamel, but I could be wrong) has cracked/split and is lifting off the underlying metal, and the further it lifts the wider the crack becomes. It is currently a small area, the crack being about 20mm long. It looks to me like water leaking around the nut seeped in underneath the enamel (?) where the enamel is cracked around the nut, and has eventually led to this damage. That is just a guess though as I am not sure whether water can seep in between the radiator and its coating, and whether this effect would result from it.

Incidentally, the leaking nut is not the one containing the bleed/vent valve - that is housed in the upright piece on the other side of the radiator (same size and type of nut, it just has the valve set into it) and is completely leak free.
 
If you still have a tiny amount of the flaked/peeled off cover substance put it on an old clean spoon and try to burn it on the open fire, a candle, the gas cooker.If it burns and smells of paint then it is paint. If it doesn't burn but (maybe) crickles without deterioating then it is enamel. Enamel would have been in the kiln before and so would have no carbon in it left to burn. But a slight discoloration when getting very hot ( when the spoon is red) would be normal though, simple metal oxidation.
There are sealant rings available in sets from the plumber shop or BQ etc. which are not made from rubber but from either compacted leather or cellulose. With the aid of a few of those combined with a rubber ring it could be possible to get a tight joint at the position you have mentioned.
But that the enamel comes off at the leak should not happen, unless the metall beneath it has signs of serios corosion. This could be the case if a primer wasn't properly applied or some other impurity was in that position when applying the enamel. This sometimes happens in the factory when the entire radiator is dipped into the liquid enamell: the openings have to be closed before this dipping (protecting the threads and saving on enamel) and that could have caused the impurity of the metall surface on which in turn the enamel wouldn't hold.
Some enameled artefacts (jewelery) thousands of years old have survived, so it can be done after all.
 
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