rusting radiators.

[plumbedinmk]

hi all..

i have come across an issue on a heating system recently, i have noticed that on all the rads, where the rad valve is threaded into the radiator, have started to corrode..(this is happenig on all rads in house total of 12).
the property is only 6 years old. is fitted with a sealed megaflow system..
i also noticed that rather than use PTFE they have used something that resembles brown mastic which has become brittle. all these radiators are leaking slightly from this location. could the use of a "mastic" substance cause corrosion at this level?

if not what could cause this problem..?
what could be done to rectify and prevent this from happening??

the system is serviced at regular intervals.

manythanks
dave

 

[doitall]

The hard brown stuff is probably Boss white.

The rust is caused by the leaks.

 

[plumbedinmk]

thanks...

 

[Nige F]

no hemp with the Bw then

 

[Softus]

what could be done to rectify and prevent this from happening?

Wait until spring, then drain down and fix all the leaks, otherwise all the rads will have rather a short life.

 

[kevplumb]

no hemp with the Bw then

hemp i trhought it was banned

 

[Softus]

Surely only on potable?

 

[kevplumb]

my joints don't leak

 

[Softus]

my joints don't leak

I bet they blow though.

 

[JohnD]

Old Fernox MB1 used to leave a toffee-like crust round joints when it leaked out slightly; the water evaporated and the traces of Fernox built up. Sometimes it dried hard and brittle enough to scratch off with your fingernails, and sometimes it was soft. I presume it depended how hard the water was or what sediment or dissolved solids it contained.

 

[kevplumb]

 

[JohnD]

my joints don't leak

creak, creak.

 

[kevplumb]

never said they don't creak john
they don't leak tho

 

[plumbedinmk]

no hemp with the Bw then

lol na, no sign of it..!

a toffee-like crust round joints. Sometimes it dried hard and brittle enough to scratch off with your fingernails.

thats a good description of what it looks like..


also another point................... If the rads are 'slightly' corroded. is it worth risking removing the rad valves to apply PTFE to stop the leaks.?. obviously if they are blatantly rusted to hell, i will need to replace the rad. ????

cheers

dave

 

[JohnD]

Maybe it isn't rust then (if it is dried-up fernox and you scrape some bits into a glass of warm water, they will dissolve).

Drain a bit of water out when the pump is running, see if it has black or brown sediment in it.

Maybe the valves are just weeping a bit. Next time we get a warm spell, you could drain down and re-fit all the valves a bit better (take the opportunity to install TRVs and Drain-off lockshields if you haven't already got plenty). You can give it a flush and refill with new inhibitor while you're at it. If the water is dirty you could give it a chemical clean.

I went over to Sentinel because i didn't like the Fernox toffee. I don't know if the current formula still does it. IANAP.