GIACOMINI valve sticking

22 Oct 2006
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United Kingdom
There is no heat in one of my radiators although the lead pipe is hot.

I can remove the top part of the valve, with the numbers on, to reveal a metal barrel left in the valve. I can unscrew this barrel and in it there is a metal pin which moves freely.

In the remaining part of the valve in the pipework there is a metal pin which moves very very slightly. I have pressed this pin quite hard a number of times but there is no extra movement.

Assuming this pin is the cause of the trouble and is stuck, do I have to hit it with a hammer (how vicious?) or spray it with WD40 or replace it altogether?

Thanks in advance for any help.
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If only one of the radiators is not heating up then it appears the diverter valve is functioning OK.

The radiator may have a problem with a stuck valve (if thermostatic) or perhaps the radiators are not balanced -see faq's.
AH ! He is refering to a Giacomini TRV !!!

The lead pipe on his central heating is rather unusual now though! The Romans used lead pipe in their heating systems!

He could tap the TRV body on the side, others say it works but never for me!

Giacomini/Gianonni why do the Italians have to have similar names :oops:

Replace the valve and stick on a Honeywell, Drayton or Danfoss valve.

Never thought much of the Giacomini Trvs although I use their excellent Aquarius valves all the time (to replace the cheapo Eurocone valves).
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Place something flat, like a spanner, on the top of the pin and hit the spanner (not too hard) directly over the pin with a small hammer about the weight of a medium sized pair of pump pliers. Keep doing this until you hear the seat of the valve break free and see the pin pop up again.

At your earliest opportunity, drain the system, replace the valve with a Danfoss RAS C2. Put some sentinel x400 in, flush the system, put some Sentinel x100 and fill up again. If the new valve starts knocking when the rad is reaching temperature, take off the head and turn the collar on the valve to reverse the flow. The knocking will stop.

If you can't do all that then get a good plumber in you tight sod :LOL:
There is no heat in one of my radiators although the lead pipe is hot.

I doubt the pipe will be made of lead.

Do you mean lead as pronounced in 'dog lead'? If so this translates to the 'flow' pipe

Giacomini TRV's are crap and every last one of them belongs in my scrap heap

Try slapping the valve about a bit as described by others above
You could try carefully pulling the pin out a little, I mean like 3 or 4mm max with pliers. But what you dont want is the pin to come right out. Sometimes it does and you get water peeing out. Funny or scary depending on what its peeing onto!

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