On Sat, 17 Dec 2016 10:12:33 +0000, Tim Watts wrote:

I decent relay should not be obviously noisy. Try an Omron brand from
RS/Farnell.

The Omron mains coil relays (MY21) I have are silent, well apart from
the click as they operate/release. B-)

His immersion needs a relay capable of handling 13A resistive load AC at
mains voltage with a 230-250VAC coil.

Not sure that they are rated at 13A resistive though wanders off to
find one nope 10A.

--
Cheers
Dave.