Boiler was banging for a bit..... now leaking? Should i be worried lol

OCdude

OCdude

OCdude

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A few weeks ago, my boiler started making loud banging noises whenever I put the hot water on and one time, the banging woke me up while the central heating was on and I noticed the pressure had dropped to 0 (it's only done that once, but the banging went on for weeks).

Since a few days ago, the banging stopped (i never got round to investigating, partly because i've been mega busy and partly because I just assumed it was air in the system).

Tonight....... the bloke next door informed me that the boiler seems to be leaking outside ...........:eek:

Before I call in the local cowboy, does anyone have any immediate thought as to what it might be?

Better not be expensive lol

TIA! :D
 
Im no expert on this but when our boiler was leaking outside it was the over pressure valve not sealing. This happened due to the "balloon" in the top of the boiler having lost its pressure so the boiler pressure was going straight up to 3+ psi everytime it was turned on. Re-pressurised the balloon and then the valve had been open so much it would n't seal. Not expensive to change though.
 
As above it could be your expansion tank has failed causing the pressure in the system to rise and it has then caused the pressure valve to open dumping the water outside. Did you notice the pressure the system was running at once the heating was on for an hour or so shoud be around 1-1.5 bar.
 
What type or boiler is it? Combi? Old school? If it's a 'normal' boiler then it could be a low pressure problem caused by a faulty ball valve i.e if it's stuck then there won't be enough water in the system.

It could also be a faulty pump or a burst pipe.

Have you checked the 'leaking' yourself?

Drukk said:
Im no expert on this but when our boiler was leaking outside it was the over pressure valve not sealing. This happened due to the "balloon" in the top of the boiler having lost its pressure so the boiler pressure was going straight up to 3+ psi everytime it was turned on. Re-pressurised the balloon and then the valve had been open so much it would n't seal. Not expensive to change though.
Click to expand...

Apologies if I've misunderstood but OP says the system pressure is down not up?
 
Pipes aren't banging at all - all the noise was coming from the boiler itself (which is a Combi boiler btw).

The one time the pressure dropped, i topped it back up to 1.5 bars... it's now around 3.5 and seems to hover around that!
 
throw an egg inside all will be fine :D (call a plumber , best to be safe than sorry you dont want it leaking water everywhere , mould , rotten floor boards etc.)
i wouldnt risk the damage that could be caused
 
I guess, but i just don't wanna be taken for a ride (like i'm sure I was last time when i had a ~£120 heat exchanger installed) :/

I've had pretty rubbish experiences from plumbers from www.trustatrader.com lol

The last one i had out.. split my bath (while fixing a leak under the bath) and i never saw him again! lol
 
OCdude, we just had the very same problem and its been fixed..

Im gonna find out tomorrow how my dad fixed it and tell you how so you wont get ripped off.

I think it had something to do about replacing a filter, but ill let you know.
 
I think you need to get a pro in once a year to give the old boiler a once over. You read every year how some old biddies house has blown up due to a faulty boiler. Ain't worth the risk not getting it looked at.
 
OCdude said:
Pipes aren't banging at all - all the noise was coming from the boiler itself (which is a Combi boiler btw).

The one time the pressure dropped, i topped it back up to 1.5 bars... it's now around 3.5 and seems to hover around that!
Click to expand...

Thats why its leaking outside. Around 3 psi is when the safety pressure valve opens and it dumps the water outside. Your expansion chamber being flat will cause this.

Get a plumber in though if your not sure. Part of the yearly boiler check your supposed to have is to check the expansion chamber pressure.
 
Drukk said:
Thats why its leaking outside. Around 3 psi is when the safety pressure valve opens and it dumps the water outside. Your expansion chamber being flat will cause this.

Get a plumber in though if your not sure. Part of the yearly boiler check your supposed to have is to check the expansion chamber pressure.
Click to expand...

Ahh right, makes sense I guess.

Thanks!
 
Some bad advice on here by people who obviously are DIY'ers which is fine for most things but not for central heating boilers.

Either your expansion vessel wants the pressure topping up a little or the diaphragm inside has split (Its more likely to be the 2nd) meaning an ew expansion vessel is needed.

Thats why water has come outside because the pressure has gone above 3 bar.

When getting a new expansion vessel fitted make sure the expansion vessel hose AND a new PRV are fitted as the prv thats on will always leak in future.


Just for future reference you shouldnt be filling it up to 1.5 - 2bar. 1 bar is all you need.

What boiler is it btw?
 
^^^ This.

Easy way to test: With a cold radiator system, fill and vent the system to 1Bar, then put the heating on and watch the pressure gauge on the boiler. If it starts to increase towards 3Bar then the PRV will release water and your boiler is now effectively emptying inself.

When the heating cools down, the water contracts, the pressure drops, but not back to 1Bar, because you have just lost water out the PRV.

I'm guessing that your bolier is one of the cheapy ones that doesnt have any pressure sensing switch or primary flow switch, which means when the boiler fires back up it doesnt know there isnt enough water in to operate correctly and starts banging due to poor circulation. Is the boiler upstairs?

You need a competant person to either/and recharge the exp vessel, replace PRV, check correct operation.

On some boilers replacing the exp vessel can be a pricey job (boiler removal), but there are external exp vessel kits available if you have room to fit one under or near the boiler and dont mind it being there.


Mick

(the heating engineer)
 
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