I over pressurised the boiler and now it won't go down

rltroth

So the other day our boiler pressure dropped, so I repressurized it but left the valve open too long :mad: and it went up to 3 (meant to be 1-1.5)

Kind of hoped it would be ok, but it soon got up to 4 and started leaking.

After researching online, I switched it off and bled the radiators in the hope it would bring the pressure down but it made almost no difference. At first I thought it was working as the pressure went down but then it came back up and has continued to fluctuate but never getting below 2.5 - even though it's now been switched off for hours.

I tried for hours, took buckets and buckets of water from the radiator with hardly any air coming out and none of them showing the tell-tale signs of having air in the top. It is now at a constant 3, and I have not turned it back on.

What can I do? Will I need to call someone out?

Any help at this point would be greatly appreciated

southcoastrgi

Have you turned the valve off ?

flashg67

Once you've confirmed the filler valve is off, you'll be surprised how much you'll need to drain to drop the pressure, I think.

One of your radiators may/will have a valve to drain it quickly - has a 'ridged' pipe to fit a hose onto.

macman

You've got a dodgy valve on the filling loop which is allowing water to flow in. Change the loop. Leave it to go to 3/4 bar and the PRV will lift, and that usually results in a new PRV, as they don't reseat properly.

rltroth

Yes I tightened the valve shut (tighter than it was when I opened it to repressurise)

I have a hard time believing its that just because the reason it happened was that I opened it too long, not that it raised by itself from leaking - but I could be wrong!

Do I need to completely drain a radiator? We did take buckets and buckets from various radiators in the system

Ruski

Your filling loop is definately letting by - doesn't matter how many buckets of water you take out of a rad it's only going to fill up again.

Filling loop 'handles' do fail - depending on the type you may be able to turn it off with a pair of pliers having taken off the blue handle bit.

HTH

Russ

macman

Read post 4. If you don't believe me, test by disconnecting the filling loop. Pressure will then stabilise, or drop when you bleed it.
Overpressure beyond 3 bar will normally lift the PVR, if it doesn't then the fault is very dangerous as you have no safety device working.

southcoastrgi

Do what macman said & disconnect the braided hose (if you have one) if you have a combi & the pressure continues to rise you have a faulty plate heat exchanger

Ruski

Be careful when removing the braided hose as it may not be shut off!!! (depending on where the valve is located)

HTH

Russ

rltroth

Thank you all for your help, I will give it a go

southcoastrgi

Ruski wrote: »

Be careful when removing the braided hose as it may not be shut off!!! (depending on where the valve is located)

HTH

Russ

Very true but really it's the only way to see if it's faulty & letting by