Glow worm 30CXI groaning noise after Hot Water switched off.

[donnypongo]

Hi All,

Do I need to worry?

The boiler is 5 yrs old, reliable until Jan when a condensate leak corroded through the return pipe inside the boiler. Then main circuit board needed to be replaced in Feb.

Problem now is just a very loud groaning/vibrating noise which only happens just after the hot water is turned off.
The groaning/vibrating noise sounds like it's from inside the boiler.
No other symptoms, CH and HW working fine.

Does any one have any ideas what this strange noise is? and if it's the first sign of something expensive?

 

[Agile]

Hi All,

Do I need to worry?

The boiler is 5 yrs old, reliable until Jan when a condensate leak corroded through the return pipe inside the boiler. Then main circuit board needed to be replaced in Feb.

You dont actually say that the PCB needed replacing as a result of the condensate leak. But any leak in a boiler risks damaging the PCB.

This is a good lesson to demonstrate that annual servicing will catch leaks in many cases before they do major damage.

For the condensate to apparently cause a hole in a copper pipe it must have been leaking for quite some time.

Tony

 

[donnypongo]

Hi Tony,
Happy to report groaning noise has stopped. Maybe mains pressure related, has been fluctuating a bit and higher than usual some days.

PCB failure probably was because boiler flooded. But it failed a couple of weeks after the flooding was cured so can't be sure.

We have an annual service, but the condensate leak was never spotted. It was probably only a drip & evaporating fairly quickly. There was never any sign of liquid, before the copper tube finally leaked.

The leak itself was from a tiny pinhole, on the back of the copper pipe, where a plastic/rubber condensate tube was resting against it. So the pinhole developed out of sight and was only spotted with a small mirror on a stick. Plus the engineer only looked for the leak after radiator water started dripping from the bottom of the boiler, whenever heating circuit reached working temperature. Engineer had never come across similar before. We were both staring at the joints for the leak, never expected it to be in the middle of the pipe.

Bye for now & thanks

Don

 

[JayPsi]

Hi Tony,
Happy to report groaning noise has stopped. Maybe mains pressure related, has been fluctuating a bit and higher than usual some days.

Bye for now & thanks

Don

Don't go, I'd like to know more about the groaning noise!

This exact problem happened to me today; HW/CH work as normal, but straight after turning off the hot water, there's a loud noise from the top of the boiler (~2 seconds) as if something is about to seize up. I don't plan on perusing the insides, but it sounds like it's coming from the top. I'd guess at a fan or pump, if my opinion was worth a <expletive>!

Recently some of our less scrupulous neighbours have been messing with the mains water supply, but I haven't noticed anything unusual today.

I'll call an engineer in the morning (the boiler was serviced in May) and see what they say. Whatever happens I'll keep this thread posted.