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.

[aftermath]

Next time you bleed the rads, bleed from the highest radiator, down to the lowest

[footycard steve]

heres the latest update - since bleeding the radiators it lasted a month before i noticed on friday the pointer was out of the green section but not down to 0 but when i opened the taps to send the pointer back up in the green section it took longer for the pointer to move up,we still have the workmen fitting new water pipes in the streets and have been working directly to the side of our house and since friday our water hasn't been coming out with the same power/pressure so i dont know if this is something caused by them or the boiler/tank ? and the workmen have not shown up this morning to ask them. will hopefully get a plumber out this week but i need to find out if the water problem is caused inside or if by the workmen outside. is it worth bleeding the radiators again this time starting top to bottom?

[DW190]

heres the latest update - since bleeding the radiators it lasted a month before i noticed on friday the pointer was out of the green section but not down to 0 but when i opened the taps to send the pointer back up in the green section it took longer for the pointer to move up,we still have the workmen fitting new water pipes in the streets and have been working directly to the side of our house and since friday our water hasn't been coming out with the same power/pressure so i dont know if this is something caused by them or the boiler/tank ? and the workmen have not shown up this morning to ask them. will hopefully get a plumber out this week but i need to find out if the water problem is caused inside or if by the workmen outside. is it worth bleeding the radiators again this time starting top to bottom?

You will get lower pressure while they are working on outside pipe work and this will cause filling through the loop to be slower. Its turned down for safety reasons.

[footycard steve]

i just caught a foreman as he was checking the works and he told me to try the stopcock with the water running i could hear a slight change in the water pressure but when i checked the taps in the bathroom and the shower they are still not working properly so he's going to get somebody to come and check,he said they have been changing the pressure in the area as they'd found a few leaks.

[DOUGALMCD]

Hi quite an interesting thread all of the info should be useful but if you don't have leaks and water pessure still dropping more than likely you will be needing a pump soon. When you fill system it is sealed. Workmen outside has nothing to do with central heating losing pressure just coincidence. Best get your boiler checked winter can be cold.

[footycard steve]

Hi quite an interesting thread all of the info should be useful but if you don't have leaks and water pessure still dropping more than likely you will be needing a pump soon. When you fill system it is sealed. Workmen outside has nothing to do with central heating losing pressure just coincidence. Best get your boiler checked winter can be cold.
we had our boiler serviced approx 1 week before all of the problems started, a workman was sent to sort out our low water pressure and he said that when they turn off/down the pressure to the property a pin has dropped out of the stopcock he fiddled with the stopcock for approx 1 minute and got the water pressure back up so we'll wait and see how the boiler peforms before getting a plumber out.

[footycard steve]

as i was going to bed noticed a noise from the toilet cistern and its filling with a steady trickle of water but it has what looks like an overflow pipe in it so its not looking like it will flood,when i lift the ball just out of the water it stops filling but i cannot rest the ball on anything and as soon as its in the water again it continues to trickle is this likely to be with having the stopcock adjusted today or is it yet another new fault? 2 a.m now so i'll check on it in the morning.

[footycard steve]

as i was going to bed noticed a noise from the toilet cistern and its filling with a steady trickle of water but it has what looks like an overflow pipe in it so its not looking like it will flood,when i lift the ball just out of the water it stops filling but i cannot rest the ball on anything and as soon as its in the water again it continues to trickle is this likely to be with having the stopcock adjusted today or is it yet another new fault? 2 a.m now so i'll check on it in the morning.
the water in the cistern was still a steady trickle but managed to catch one of the workmen who said maybe the pipe had sucked up some dirt with the change of pressure but he did manage to get it down to a drip,20 mins later i ran the bath and the water was only luke warm and the shower wasnt much hotter but the radiators are still nice and hot when they come on so its just one thing after another at the minute including a broken oven.

[DOUGALMCD]

Hi Steve you are not having much luck are you. with water pressure going down because of outside work you will get dirt in your freshwater supply. If your toilet cistern does not shut off fully it's probably small rubber washer that's worn at join of pipe and ballcock arm 20p worth.The slow filling is purely down to water pressure or dirt at nozzle where washer goes. All of this is still unrelated to problem your having with heating. As for oven if it's electric and not heating up probably the element easily replaced. the element will have number or code use google or ebay. Always turn water off before attempting washer inspection same goes for electricity at oven. If your not good at diy please use professional. Better safe than sorry Good luck.

[footycard steve]

yes its an electric oven and did think it was likely to be the element but i dont have a clue what i'm looking at, had the heating on a bit and the hot water in the bath was definately warmer than earlier, have been in touch with council for list of approved tradesman, found out today our insurance company no longer in business and its due to be renewed this week so also have that to sort out now,

[cgscott]

Check the thermostat in the cooker first.

[McMav]

Holy Thread revival. I have same problem butI've traiseld it to the pressure release valve as the pipe outside has watter dripping from it. Time to call the warrenty folks I think. As said its a sealed system so pressure outside dropping would not have had an effect on the pressure in your system.

[cablefreejunkie]

i just had the pressure relief valve changed at home,,the bath would take an hour to fill,now it fills in under 5 mins,,anyway my pressure in the system drops aswell,got no leaks as far as i know and ive bled the rads and pressured it up again etc,,not sure why it keeps dropping,,any ideas from any plumbers on here ?

[gizmo.1484]

Check the pressure relief pipe outside to make sure it is not dripping as the pressure relief valve might not have sealed properly when fitted.
If not dripping then there is defiantly a leak in the system. Check all joints around the rads.

[cablefreejunkie]

Check the pressure relief pipe outside to make sure it is not dripping as the pressure relief valve might not have sealed properly when fitted.
If not dripping then there is defiantly a leak in the system. Check all joints around the rads.

the clown that plumbed this house before we moved in did not vent the pressure relief pipe outside,,he was a complete tosser with no skills whatsoever (dont start me off ive got a list as long as my arm) of total ~~~~ ups he has made in this house,,,anyway the vent pipe is in the cupboard with the immersion tank,,nothing is leaking well not above the floors that i can see although he has used easifix pipe to plumb the whole house and a coupleof the joints leaked at the kitchen taps
in all honesty it probably needs ripping out and replacing

[upperplumbers]

it could be a few things:
1. if it takes more than 1 day pressure to drop than a leak sealer will stop a small leak in the system. Just inject it into the central heating system like it says in the instruction
2. to see more

[DOUGALMCD]

I would always prefer to fix system leak properly instead of patching it up as above mentioned.

[trent1579]

check to see if there are any leaks if there are no leaks it is the expansion vessell which is either knackered or needs pumping up,if you can locate the expansion vessell it has a schrader valve(same as car tyre) simple let some air out if water comes out,the expansion vessell needs replacing,if no water comes out then the expansion vessell will need repressurizing normal to 0.5bar to do this the system needs to be depressurized then use car pump to pump up to 0.5bar

see link for more help
How to check the pressure of the expansion vessel. - YouTube

How to recharge an expansion vessel in a combi boiler - YouTube

[ricescooper]

I've got the same boiler and had this issue for a while now. Its really weird because the pressure in the system can be fine for months then it will play up again for no reason.

I had a major problem that the insurance had to fix but they took out everything and didn't put it all back with the same care as originally was taken to install kitchen, boiler, etc. I've had one problem after another since they done the work, all seemed fine at first then everything started falling apart after about nine to twelve months.