Screaming Boiler!

Oh help, it never rains .... after congratulating myself yesterday for having got the old boiler running again (new pump fitted, rads all working) I've just had to power the boiler off at the mains very quickly!!

There's an 'orrible screeching noise coming from said boiler, right down in the business end of it. Doesn't sound good at all.

I haven't the first clue what it does with my oil when it gets it, but the noise it is making happens whenever you restore power (it goes through this little ritual where it sounds like a fan is switched on for a good few seconds prior to igniting the burners and doing the biz). The screeching starts immediately you switch on, so I can't bear to leave it on long enough to see if it will actually fire in case it just self destructs!

Any ideas anyone? The boiler is a Worcester Heatslave 15/19 Oil Fired. Back to boiling kettles again .......

Humbly yours, Anne

I dont really understand your situation properly. You say that you replaced the pump, apparently yourself.

Did the boiler and new pump work properly and quietly for several hours afterwards?

The most common component to squeak is the pump if its running dry! I assume that it is something else now?

Boilers are quite complicated appliances and if you cannot identify where the noise is coming from then perhaps you need a boiler engineer?

Tony

Hi Tony,
yes I posted a thread yesterday with more detail - (see the one called Gremlins in my Heating!). I replaced the pump on Saturday, the old girl got going again and ran apparently fine all day yesterday.

The probs I had after putting the pump in were
1. Some rads not warming up (after the advice given on yesterday's thread I turned off the ones that were working and it brought the other 3 through OK)
2. Heat getting to the rads even when the programmer was only requesting hot water (and I'm guessing that this is a fault with the motorised control valve, confirmed by the advice I got yesterday).

Those two issue notwithstanding, this morning the boiler started making this screeching noise, not from the area of the pump but from the real business end where it does the spraying of oil and burning. Whenever it starts it always does this pre burning routine, where you hear what sounds like a fan coming on, then after a few seconds you hear the burner ignite. Well, the screeching is coming from the bit that normally sounds like a fan and now sounds like a piece of machinery in dire trouble. It's definitely not the pump, I've just undone the pump screw to look and it's full of water (I bled it up lots yesterday while running the system).

I'm probably going to need an engineer, granted, but I wondered if anyone could advise on what it's likely to be (and if the boiler sounds on its last legs I guess). I'm not very technical but I try to understand the basics so I can make better decisions - somehow I don't think me and a spanner are going to be up to this job.


Any advice appreciated

Anne

You imply that the fan starts quietly and the noise only starts when the burner ignites.

Its possible that its actually the combustion process making a noise.

I would recommend that you get an Oftec registered person to look at it. If its not leaking water from the main heat exchanger then I would expect that it will be quite repairable.

Its better not to use it while it makes the noise as it might further damage a repairable part.

Tony

Sounds like either the fan rubbing on its casing or a problem with the oil pump. Best to call in whoever services it for you as air flow and oil pressure will need to be set up after anything is looked at anyway.

Thanks both for your replies.

The noise starts straight away when you switch on, I've not even reset the burners as I can't stand the screaming long enough (and that's the boiler not me )

To my untrained ear, it's like a when a bearing or something breaks down, and it's a horrible metal on metal whirr (after you switch off the power you can hear it slowing down as whatever it is finishes spinning round). Could I have caused this after changing the pump, or is it just bad luck and a history of patchy maintenance?

We've inherited this little beauty but I would guess there's not been a lot of annual servicing. (The pump was like for like, set at the same speed etc)

yep sounds like motor bearings are worn.