Help please - Low pressure in gas boiler.

locum-motion

I have a gas boiler which isn't working, the 'Bar' LED is flashing, and the pressure gauge is reading about 0.8 bar.

On the instructions, it says "The reading on the pressure gauge must be between 1 and 2 bar. If the pressure falls below 1 bar, the heating system must be repressurised via the temporary filling loop"

So, can anyone tell me, what's a "temporary filling loop", what does it look like, where do I find it, and is it something I can do myself or do I need to get a plumber/gas fitter in? Do I need any tools?

Thanks in advance.

sullzz

The filling loop should be located in your hotpress it's a silver flexible pipe with a black 1/4 turn knob on it , there are lots of threads on here telling you where to find it , search them and they will also tell you how to go about repressurising your system .

locum-motion

Thank you, Sullz.

As it happens, I was able to sort it out after a quick phone call today.

But thanks anyway.

mjth2004

Similar question...

Ferroli gas combi (tempra 24) pressure reading on boiler is at 1 when both the central heating & hot water are on together but when heating water alone pressure reading is just a little above 0. Also there is a light flashing on the control panel, which on looking at the book is 'central heating stand-by' - every 5 minutes or so this light stays on for about 30 seconds (central heating circuit on) but the returns flashing.

Any help or info will be welcomed!

Cheers!

mjth2004

Any takers before I ring a plumber?

If it's a simple fix would rather give it a go myself!

Cheers.

Delta2113

How long can it take to top up a boiler 10mins or 20mins or longer? I had to top up a few months ago and it was taking so long it only went near 1 bar and i stopped it. Now it is going low again boiler is on 0.8 and it says it will stop working at 0.7.

The time taken is dependant on your mains water supply, the stronger The supply the quicker it fills, it's always worth having the filling loop checked if your having problems.

Delta2113

gary71 wrote: »

The time taken is dependant on your mains water supply, the stronger The supply the quicker it fills, it's always worth having the filling loop checked if your having problems.

Say every 6 months when it goes completely down and the boiler stops giving error message and flashing light could it take 30-40 minutes to fully top up or is this too long?

Delta2113

Delta2113 wrote: »

Say every 6 months when it goes completely down and the boiler stops giving error message and flashing light could it take 30-40 minutes to fully top up or is this too long?

The fact it fills is more important than the time taken, it sounds like it takes along time but apart from it being a pain in the behind I wouldn't be concerned.

All sealed heating systems lose pressure over a year so to have to top up twice a year wouldn't be unusual.

Delta2113

Had to top up again - gauge on filling loop only goes to just before 10 in red. It wont go to 1 in black but my boiler is working again. Should I be concerned? I left it on for 15-20 mins and it just would not go any further. The boiler itself is now on 1.0 bar.

Delta2113

Delta2113 wrote: »

Had to top up again - gauge on filling loop only goes to just before 10 in red. It wont go to 1 in black but my boiler is working again. Should I be concerned? I left it on for 15-20 mins and it just would not go any further. The boiler itself is now on 1.0 bar.

Always take your reading cold and with the boiler off.
Keep writing down when you topped up the boiler and what the starting point was.
If it is once every 6 months then that wouldn't concern me, be aware if you start to top up more often then you could end up with sludge in your heating system as you dilute any inhibiter in the water(if added during installation), ask your RGI to look at the filling loop on next service.

Delta2113

The last time I topped up was 10 March - about 4.5 months ago but i did not wait for the boiler to stop working then - just that it was low. This time the Boiler did stop as it had gone below 0.7 -showing 0.6 with red light. Hopefully I will get a full 6 months. Any idea why I cant get it to go up to 1 in black at the filling loop?

Delta2113

Delta2113 wrote: »

. Any idea why I cant get it to go up to 1 in black at the filling loop?

Either your incoming mains is only 0.9 bar or the filling loop between your heating system and mains water is defective.

Delta2113

Had the boiler serviced last month and asked the guy to check the loop. He said it was fine. I actually did a top up on Oct 16 but again I did not wait until it completely cut out but it was low. Maybe silly but I was afraid it might go when he was coming out to service it. Anyway again today i went and switched it on and never came on and went outside -red light 0.6. i topped it up but again it did not go up much. I rang the service guy and explained what happened - he offered to come out tomorrow (tuesday) but he said that there was no way for him to get the pressure to go up anymore.

I went back outside to boiler and switched it off - then back on and it made some noise -got a green light but still 0.6. I went back in and turned it on and it worked. Not sure how long i will get this time.

Has pressure in Dublin really gone so bad in last year? Nobody can explain why i cant get it to go to 1 bar.

You're heating system requires 1 bar to work, your incoming water mains is not strong enough and it down to the water company what pressure the water is they give you.
Their is nothing I'v seen that will improve your mains, it's been posted on here before that there are small pumps that are acceptable with water regs you can fit to your mains, but I have never seen one in action, other than that try filling late at night when demand drops off, you could also fit a small pump fed by a break tank, a plumber may have better ideas.

Delta2113

In hindsight if i knew this could happen i would have topped up say every three month's regardless. I'm sitting beside my hot press with the loop open now for the last hour and half - it doesnt want to budge. At least yesterday i could hear the water going in but not today. i have 0.8 out at the boiler so it will work but if i get a few days or a few week's i'm not sure - i'd guess a few week's. Should i just start topping up every month?

I must admit the water pressure in the area is crap.

hotfeet

If your boiler pressure is dropping frequently it could be a sign of a leak within the heating system,,these can be sometimes hard to dtect as you can have either a cold leak.ie system develops a weep when cold or a hot leak, system develops a weep when hot,,,expansion and contraction, etc,check all your rad valves and your flow/return connections for signs of a weep/leak,common location would be in hotpress at cylinder connections.
Depending on where you live lime deposits can be a problem also.

Delta2113

Yes the system has a leak (s) but very small. The plumber put inhibitor in the system over a year ago and said he may have to come back and do it again.

I didnt get him back because i seem to get a few month's out of not having to top up. Twice or even three time's a year is ok but now i have the problem that i just cant get the system to top up enough to last me any length of time. I have the heating on now and it's fine - 0.8bar reading on the gas boiler. Boiler wont work when it drop's to 0.6. Hopefully it will last at least four week's and then i will try and top up as suggested late at night when the water pressure might be better.

As i say my problem is getting the pressure up. When it was installed the pressure was 1.2 bar - i can only get it up to 0.8bar. I hope people can follow this.

thanks again for any help to date.

heinbloed

Delta2113 wrote:

.....but he said that there was no way for him to get the pressure to go up anymore.

Well if the leak leaks faster than the system can be refilled - that's it.
Get the leak repaired first. A permanent freash water input into a CH systems puts a high risk of lime sediments settling on the heat exchanger. Resulting in a an inefficient heating system and a shortened life time.

The pressure at the water mains can be meassured, ask your plumber to do this.
A statement as quoted above is wrong, get a real heating engineer in. There are water pumps which can be used to pump water from a reservoir (for example a bucket) into a heating system to achieve the wanted pressure.

Delta2113

I dont want to have floor boards taken up etc. to find a tiny leak. I dont have a permanent fresh water supply going in as i close the filling loop. The leak is not faster than the system can be re-filled -the problem is i just cant get the pressure up to say 1 bar on the gauge in the hot press.

I probably would get the plumber to try the inhibitor again in the system. He told me before to not worry you dont have a huge leak or anything.

heinbloed

heinbloed wrote: »

Delta2113 wrote:



Well if the leak leaks faster than the system can be refilled - that's it.

.

If the system had a leak that matched the mains flow then the system would be at zero very quickly after turning off the filling loop
There is no point measuring the incoming mains as the boiler guage is indicating the pressure, only a pressure reducing valve will limit the pressure and even if the mains was slow the pressure would still equalise at some point.
Also a leak sealer maybe what you mean(i don't like them) and only add inhibitor to clean water, adding it to water that is/maybe dirty is worse than not having any at all.


Heinbload, please stop giving plumbing advise, you have no practical experience which is evident by your last post, it's not funny to confuse people intentionally or unintentionally who are seeking help with some of things your "authoritative" posts advise, you are very strong in some areas but you're just wrong in others.

Delta2113

Thanks Gary71 for all your help to date. Yes sorry leak sealer is probably what i should be saying. The last time when the plumber did it he said it traveled around the pipes and if it came across a microscopic hole it would seal up the hole. He did say he may have to come back and give it a second helping so to speak.

I suppose the fact the weather has been so mild we have not been using the heating as much so pressure dropped over time quicker.

I'll keep monitoring it and as i said before maybe in four week's try topping up late at night. Personally i could handle topping up every 4 months but if it was more than that i would get plumber back.

hotfeet

You can get a pressure testing bucket, its basically a bucket with a pump and a guage attached that could be used to pressurise your system, the leak seal would probably work in the short term,but in all my years i have yet to find a leak that repairs itself, I can only presume that your mains water inlet pressure is low or reduced by utility company,,as a previous poster suggested you could try filling the system late at night when demand would be low anyway.

I would ask your plumber to check the system water condition when he's there next, the quality of the water should taken in to account when your thinking about the next step, a leak on the system can help encourage contamination which can limit the life span of the boiler, as you only have a small leak it maybe enough to confirm your water is clean than add a inhibitor to protect the heating system then add inhibitor as needed to keep the concentration up.

Delta2113

Got the plumber out today - basically he said the mains pressure is low and he wants to fit an automatic filling loop. He said then you wont have to keep checking it. I expressed my concerns and said sure i can do it manually. He said the automatic filling loop will not make the pressure any better but it might just save you one day if say you got a burst outside on the road -your pressure would be ok -whereas if you did it manually it could have gone low and then when burst outside you could not get the boiler to work until burst outside is fixed. I hope this makes sense.

He also wants to put in internal leak sealer.

aujopimur

Leak sealer yes.
Auto fill no.

Delta2113

€160 to fit automatic filling loop

€110 to put in internal leak sealer

This about right? Still not convinced on the automatic fillimg loop?

EmmaH

Hi Guys,

I have a big problem and I need some advice.
I recently (about 3 weeks ago) had a new boiler installed with a few extra things.
Its a Vokera system boiler, pressurised.
On the first day I noticed that the pressure was very low. I rang the RGI plumber and he told me to top it up using the filler valve in the attic.
I did this, but notice that it is dropping 1 bar a day.

The house works on a drop system, so, apart from an extension, there are (to my knowledge) no pipes under ground. All pipes come down through the walls to the downstairs rads.

I have had two leak detection guys in already. One fella had a low tech tuning fork style devce. The other fella had a high tech instrument.
Both guys said that there was no evidence of a leak anywhere.
If there was...you would see it.
I measured out a bar in pressure by bleeding a radiator. It is about 1.5 pints of water. How could my system be losin 1.5 pints of water a day, and not be evident.

At this stage I'm starting to look back at the boiler.
I have no idea where the water is going.
I don't want to use leak sealer like fernox just yet...especially if i don't even have a leak.
I don't want to be continually topping up the system. I'll be letting in lots of oxygen, flushing away my inhibitor, and my boiler won't last 5 years.

I don't think that the water is going out the brass 'blow off' pipe out the back of the boiler, because the ground is always bone dry. However, I have placed a bottle under it tonight to see i anything comes out. I'm not hopefull.

Please, please help as I am out of ideas.

GASMANN

gary71 wrote: »

Either your incoming mains is only 0.9 bar or the filling loop between your heating system and mains water is defective.

op might have an autofill/pressure reducing valve set at a bar set at 1bar ?

GASMANN

GASMANN wrote: »

op might have an autofill/pressure reducing valve set at a bar set at 1bar ?

Can't be ruled out, but the plumber wants to add one which he may not have offered if one is already fitted:D

EmmaH

EmmaH wrote: »

Hi Guys,

I have a big problem and I need some advice.

After you proved it's not the pipe outside and you wanted to nail if it's system or boiler then you could pressurise the system then with the boiler left off isolate the flow and return valves(maybe get a plumber) leave it for a day or two, check the pressure if it's dropped then it's the boiler, no drop then open the isolation valves if it drops then it's your system that's leaking.

If you have a leak on your system then you may want to isolate the cylinder flow and return to rule out the coil in the cylinder, once you've proved it's the pipe work then you could go old school and try isolating half the circuit wait to see which Half loses pressure and keep isolating sections till you identify the culprit, this work is best done in summer by a plumber who has a bit of time on his hands:D