Gas boiler query

Gizmo21

Has anyone any idea what this could be? We've had gas engineers visit regularly for the past 3 months, but because it doesn't do it when they're here, they have no idea what it is. It can happen at any time, it can happen when the central heating is on or just when the boiler is heating water up. I have my suspicions what it could be, but whenever I suggest it I'm told it can't be because because the boiler is only 4 years old. Surely that makes no difference whatsoever?!
https://youtu.be/9Y8unxrtvCU

matelodave

Sounds like it's the fan bearings

Gizmo21

Thanks for your reply. The fan has been replaced, but it's still doing it.
Theres also a reduction in its performance. It starts off heating the radiators to a point where they're too hot to touch regardless of what number we have the radiators on, they say that's normal, but I've never known them to do it.Then after an hour or so it'll click on for 10 secondsor up to a minute and click back off even though the radiators are still cold. Then in the evening it'll stay off for an hour or more. If we turn the thermostat up to 23 degrees it doesn't switch off at all. They cut our condensate pipe outside because they said it could be rainwater backing up into it, but it wasn't, which I knew it wouldn't be. We're pulling our hair out with it, it's so frustrating!

Northlight

Sounds quite like something called kettling, where flow through the boiler is impeded by sludge or debris. Is there a filter on the system? Or if you have ever bled the air from a radiator or towel rail etc, what was the condition of the water?

Gizmo21

That's one of the things I'm thinking, a sludge build up. I asked them weeks ago if it could be that and the engineer said no. I've no idea about filters etc, I don't poke around with anything concerning gas as I worry too much. They keep telling me it's safe, but with suffering from anxiety, it does affect me. There is one radiator that is warm at the top, but cold at the bottom (that's when the radiators actually heat up) but again they just say it's normal, which I know is definitely not  normal. The radiators haven't been bled so far.

Gerry1

Gizmo21 said:

That's one of the things I'm thinking, a sludge build up. I asked them weeks ago if it could be that and the engineer said no. I've no idea about filters etc, I don't poke around with anything concerning gas as I worry too much. They keep telling me it's safe, but with suffering from anxiety, it does affect me. There is one radiator that is warm at the top, but cold at the bottom (that's when the radiators actually heat up) but again they just say it's normal, which I know is definitely not  normal. The radiators haven't been bled so far.

You don't have to worry about gas when you're draining the sludge out of the water filled system or bleeding the air out of the radiators.  Look for something like this at the lowest point in the system.

You'll find lots of info online, or just get a plumber to do the job if you're not confident.

Gizmo21

Oh right, I didn't realise draining the sludge was something we could do ourselves. We'll give it a go. Thanks

Talldave

If the system is really bad, you're probably in need of a proper system flush, which is probably a job for a plumber. A recommended local plumber is a better option than a company you've never heard of offering all sorts of treatments and additives that cost a fortune.
But start by bleeding all the radiators to get any air out the system.

Gizmo21

Thanks TallDave. We'll start with bleeding them and go from there.