Worcester 280 - HW popping reset switch

[sayitaintso]

Hi all,

CH works fine, ticks over nicely, got us through the recent cold snap no bother.

HW works, but when you switch the tap off, it causes the reset switch to pop. Happens more when the CH is on. 9 out of 10 times, hit the reset and you're good to go, but sometimes there is resistance and push back on the button. Have to let it cool down before restarting.

At the point you switch the HW off, the pressure gauge bounces around a little and there's a bit of banging.

This morning, looked at the pressure gauge and there's a massive pressure drop, went from 1 bar to 0.4 bar. Noticed that outside the floor is soaking by the overflow/release pipe(?). There is now a drip-drip from the pipe.

My plumber reckons it could be a number of things, but that all parts are now obsolete and/or eye-wateringly expensive. He's pretty much said, don't throw money at it, save for a new boiler. In my heart-of-hearts I know he's right, but I thought I'd roll the dice one more time.

Any thoughts/ideas?

 

[sayitaintso]

It just happened again. The wife was running a bath, before she turned the tap off, I turned off the hot water on the boiler itself, but left the tap running. I hoped that the water running through the HEx would stop it overheating. No luck.