Checking 3 port valve. How?

[stoobydale]

Someone wrote in a previous thread,"
"the 3 way valve was not sealing when the h/w circuit was meant to be off "

How would you check for this? I have a noisy CH system as posted in an earlier thread, I have since balanced the radiators, but we still have the noise. Is it possible that I could have the same problem as above. The 3 port valve was changed last year for a "Tower".

 

[Softus]

The Tower body is rumoured to be made in the same factory as the Honeywell part, so there should be no problem with quality. The head, however, is different, and is a bit cheap and nasty.

You check for failure to seal off by starting with the system cold, and selecting hot water only (or CH only). The pipe to the CH (or cylinder) should remain cold, or tepid (from conduction). If the wrong pipe gets hot then the valve is passing.