Immersion heater rattle

Krusty_Clown

Hey there, had our 20+ year old water cylinder/immersion heater replaced around 7-8 months ago, when we were getting our bathroom refit. Worked fine over winter when heated from gas boiler, but during the summer, we've been using the immersion to heat the water in the cylinder. About 20-30 minutes after turning on the immersion, we're getting a lot of loud rattling from within the cylinder (doesn't happen when water is heated from gas boiler). The thermostat appears to be working fine and isn't an overheating issue (rattling starts within 30 minutes of turning on the immersion heater). Doesn't seem like it could be a hard water issue and the tank is very new so scale-buildup is unlikely. Can't really bring the bathroom installers back (other side of the country), so I'm wondering if there is some way to diagnose the issue, so I can figure out if its a plumbing or electrical issue. The immersion heater on/off switch seems to get very warm. Thanks!

Twofeet

I have the same problem. Rattle starts within 10 mins of turning on the immersion. I think the immersion element itself is a flimsy piece of tat and not made to last! Mine was replaced by a plumber. I suspect he bought the cheapest he could find, even though his fee to install it wasn’t cheap! I suspect replacing the crappy element with a more robust one will solve the problem. Did you ever get your issue resolved?

Krusty_Clown

https://www.boards.ie/discussion/comment/122557124#Comment_122557124

I did thanks. I had two plumbers in who couldn't figure out out. I bought an immersion spanner and gave the entire unit a tighten, and that seemed to do the job. Hasn't rattled since. €10 well spent.

Twofeet

LOL. Well done and thanks for taking time to leave a comment. The cap on mine is already very tight, so must be something else ….

Krusty_Clown

https://www.boards.ie/discussion/comment/122558060#Comment_122558060

Mine seemed very tight too, but the extra nudge was just enough to kill the vibrations.