boiler pressure keeps dropping

[footycard steve]

we have a worcester greenstar he boiler and over the last 3-4 weeks the pointer has been dropping out of the green reccomended pressure section 1-2 down to 0, three times now i have had to open the taps on the pipes to let the water/pressure rise back into the green when its back up i leave both the taps pointing at midday but its only lasting 7-10 days in the green pressure before dropping to zero,we have been having new water pipes laid in the area for the last 3 or 4 months and they've been turning the water supply off (did this morning and thats when i noticed pressure down at 0 it was okay monday) we also had the boiler serviced just over a month ago and had no problems reported. is it dangerous that the pressure is keep dropping or could it be something simple?
any help/advice welcome.

[footycard steve]

i put the heating on while pointer was at 0 after the water supply coming back on and it has risen just into the green segment only just in though,so to me it seems like the ongoing pipe laying is definately causing pressure to drop but might not be the only cause?

[gizmo.1484]

The central heating system is a sealed system. So will not drop with yw laying new pipes. It sounds to me, that you have a leak Somewhere on the system. But it could be air trapped in the system, best thing to do is bleed all radiators and see if that sorts it. If not then you have defiantly got a leak.......


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[titch69]

i think if u had a leak u would have noticed damp patches by now if u say it lasts for 7 to 10 day wich to me sounds like its been happening a while where is the boiler situated

[footycard steve]

The central heating system is a sealed system. So will not drop with yw laying new pipes. It sounds to me, that you have a leak Somewhere on the system. But it could be air trapped in the system, best thing to do is bleed all radiators and see if that sorts it. If not then you have defiantly got a leak.......


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last december we had frozen pipes and did notice that the towels and bed linnen kept under the boiler were damp and it seemed it could be coming from one of the copper pipes,the pipes downstairs burst on xmas eve and when the plumber came out he checked the boiler pipes but said they were fine and we've not had any signs of leaking since.

[looly]

If it is a leak then apart from pipework it could also be a faulty prv (pressure relief valve).
The prv will have a pipe leading off it to the outside so have a look outside where the pipe exits the wall and see if there are droplets of water seeping out. Differentt prv's have different pressure thresholds but yours should definately not open up under 2 bar.

HTH

[jcgrumbles]

go round checking all your vaves when the systems cold cos when they are hot they will evaporate any weeping,and you will never trace the leak,dont forget the tops of your rads cos they can suck air in,theres a slight chance you have a pinhole in your expansion vessel which would play havoc with your pressure,most of them have a nipple on that you can check with a pressure gauge

[footycard steve]

i've just filled the pressure up again and when i closed off the tap i got a small spray of water from the tap, i was also wondering if the problem could be under the bath as we had new taps fitted to the bath and the sink at the same time as the boiler check up and it was only about 5-7 days before i first noticed the pressure had dropped.

[DW190]

i've just filled the pressure up again and when i closed off the tap i got a small spray of water from the tap, i was also wondering if the problem could be under the bath as we had new taps fitted to the bath and the sink at the same time as the boiler check up and it was only about 5-7 days before i first noticed the pressure had dropped.

Totally separate supply to the taps so not that.

While the heating is off and the system is cold open the valve to increase the pressure to at least 3bar, close the valve and bleed all the rads, open the valve to get the three bar again and check all joint and valves for slight leaks. The tinyest of leaks will cause a drop in pressure over a period of 6-10 days.

More often than not it'll just be an olive seal under a rad valve that needs tightening.

Tiny leaks dry in seconds when the system is on and the pipes are hot.

[Donka]

You should have a pipe running to the oer. If this is leaking water slightly your pressure relief valve is faulty. This may have been caused by the heat exchanger corroding inside and leaking into the system forcing the PRV open and then these never close properly afterwards. My advice is this, if not insured get it insured now. As it's still useable leave it a month or so then report it. If said insurence would like to look at system before agreeing insurence just make sure pressure is up when they call and it should pass all checks as this is not what they are looking for. The Heat Exchanger is the dearest part in the boiler and to replace this would be more than the boiler is worth. I know of at least 2 boilers worcester that this has happened to. Let us know how you get on thanks

[footycard steve]

have checked the radiators for any signs of a leak when cold but not found any signs,couldn't find a radiator key to bleed them and dont live near a hardware shop and every time the idiot goes shopping she keeps forgetting to buy one,i put a plastic dish under the pipe area i think was leaking at christmas but completely dry. not sure of some of terms being used oer and different valves etc but i assume it will be a pipe on the outside of the bathroom wall if so its likely to be wet from rain?

[mast]

Hi

When being advised about valves they are talking about the trv`s and the lockshield on both sides of the radiator where the pipes meet the radiator.

Check that the nuts are tight as sometimes if not tight enough the olive inside the nut has not grabbed and can allow seeping which is not always noticeable.

Also as has been said bleed the rads for air as explained before.

Could also be the prv just check it to see if its sat back properly but as been said they dont always sit back once they gone and would need replacing.

These are the most obvious reasons usually.

Regards

[griff]

Make sure the heating is on when checking the blow-off or prv. If its not that or a leak it will prob be ur pressure vessel in the boiler might need re-charging. I would be surprised if u had a leak in ur heat exchanger in a greenstar boiler because they are stainless steel and have a 10 yr warrenty

[hotlife]

It sounds to me, that you have a leak Somewhere on the system.

[footycard steve]

just bled the rads some hissed then let out water others just let out water and the one in the bathroom took a little longer to let out the water and the water was dirty,i turned the pressure up to near 2 before bleeding and again afterwards so will wait and see if it starts dropping again.