Worcester 24i high pressure !

[Andy iow]

Hi everybody
Can anyone help with my problem ?
The pressure on my Worcester Boiler has risen to 3.5, and the overflow is dripping water.
I found a red knob inside the boiler which releases water from the system.
When I turn it, the water gushes from the o/flow ..... but the pressure stays at 3.6 ...... which is too high I think.
p.s. don't know why it is suddenly so high, it has stayed around 1.5 for monthss.
Anyone else had the same problem?
Cheers
Andy

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[chrishutt]

Sounds like your filling loop is open and letting in mains pressure. If you don't have an external one, some Worcesters have internal one which operates with white plastic key.

 

[Andy iow]

Thanks for the tip ........ I have checked the filling loop, but the screw is tightened fully clockwise so I think it is closed. I turned it anti-clockwise to check if the pressure moved , but nothing happened !!!!!

 

[ChrisR]

Which sort of filling loop do you have? There's one with a white key, one with a grey key separate ones...

If you're sure the FL is not passing then the boiler's secondary heat exchanger, where the boiler water heats the tap water, is leaking between the two.
On your boiler that's the same h/e as the gas to water one, so a new one is expensive, plus fitting, maybe £300.

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On reflection though the heat exchanger looks like it has two tubes which don't touch

So I might be talking rubbish

 

[chrishutt]

Your right ChrisR. Worcester 24i has combined main heat exchanger (what is the proper term for this - double pass, 4 tube?). But before concluding that this is problem, remove flexible part of filling loop (if external) just to be certain that it is not letting by.

Ah, just realised what you mean ChrisR. If the two tube sets aren't in close contact, there can't be leakage from mains side to CH side. Good point.

 

[Andy iow]

Yes ...... the flexible filling loop is visible, but there is no key in the loop !
There is only an in-line screw next to the filling loop, and this is tightened fully clockwise so I guess it should be closed ?
The pressure is still 3 plus and water coming from the overflow.
Would a new filling loop/fitting help ... maybe the screw/valve is jammed ..... just a guess ....

 

[Paul Barker]

You might be confusing the double check valve. First check to confirm your filling loop is not letting by is to remove it. No water should come out of either end. If it does don't blame me, this is part of establishing what is going wrong, crack it with care let it drain into a bucket progree to removal, if the drips never stop, that is your problem. Buy a new complete filling loop, put the double check valve at the boiler end, remove the loop once boiler is filled to both comply with water regs and save your boiler from damage the next time.

Before this is all over you may end up with a new cartridge in the pressure relief valve. Your expansion vessel should be checked as a matter of course.

Don't they call that a biflow heat exchanger? It is unlikely to be the cause isn't it? I think it's the filling loop.

I take them off and cap off on new installations to train the customer, so these problems are avoided.

 

[trev123]

either your diagphragm has split in your pressure vessel or it might need repressurising . to do this you must release the pressure first then pump the presure vessel up with a foot pump, if you look you can see the nipple, pump it up to 1 bar once you have done this refill the boiler to 1 bar , if it stabilizes , ok , if it rises again you need a new vessel.

 

[trev123]

you will need to repressurise your pressure vessel big red thing at back , to do this blow pressure off turning little red knob. then pump up the vessel by using foot pump to 1 bar, after this refill boiler yo 1bar

 

[chrishutt]

Sorry, trev is wrong. It's not the expansion vessel at fault. If it was, pressure would only rise when heating was operating, but your pressure is building continuously. Suspect that filling loop is not turned off, but you won't check it as suggested several times!

 

[ChrisR]

Have checked - this woosta doesn't have a key in an internal filling loop.

Yes ...... the flexible filling loop is visible, but there is no key in the loop !
There is only an in-line screw next to the filling loop, and this is tightened fully clockwise so I guess it should be closed ?

the slot of the screw should be at 90º to the axis of the pipe it's on , to be closed. Once this is done, unscrew the "winged" nuts at each end of the braided flexy part, which is the loop. If it leaks put it back and call Houston.