Old Italian heating system

[joandsimon]

We have a very old stand-alone wood burning boiler serving several radiators. The boiler has just started to leak - not totally unexpected - but no water has been coming in from the header tank to replace the leakage. By now quite a bit of water has leaked out.
I have inserted a good length of plastic tubing into the outflow pipe in the header tank and blown quite a bit of air down it. Bubbles eventually come up around the plastic tubing but still no flow to the boiler.

Any thoughts on what might be the problem?

Thanks

 

[JohnD]

sediment clogging the feed pipe. Quite likely where the (small) feed pipe joins the (large) circulation pipe in a "T".

If it has compression joints you could take it off and prod it clear.

If your stove runs short of water it will overheat and probably melt some soldered copper parts.

 

[joandsimon]

Thanks for that John. The pipe system is extremely starightforward with 1 downward bend from the header tank, and 2 horizontal bends around internal corners with smaller diameter pipes going up into the radiators.
Would it be possible to purchase a small bore flexible metal "snake" - like a flexible electric drill drive to reach awkward places - that could be threaded down the feedpipe?

Thanks.

 

[JohnD]

You might possibly be able to, though most drain clearing wires are intended to go down bigger pipes. it's more usual to cut out the blocked part or dismantle it to clear; if you poke out the sediement it has probably gone hard so the lumps will go and cause a block somewhere else. Have a look and see what joints you could undo.

There are chemical cleaners you can get; the trouble is that once a pipe is blocked, no water or chemical will flow through it, so your blockage is unaffected.

But if you can clear the blockage, chemical cleaner and flushing will remove some of the other grime in there.

 

[joandsimon]

Thanks a lot John. We are going out again at the beginning of May so hopefully I can do something with it!