Gas boiler flame keeps going out when run the bath

[boilerboy22]

Hi

I have a BIASI gas boiler as in the pictures.

Its worked fine for 12 months. But now, for the last few days, when its first running the bath, I can hear the gas flame turning on and off…and the bath water is quite cold…..if I leave the tap running for say 5 mins, then the gas does stay on permanently.

When I look through the little oval “window”, I can see the flame lighting and going out repeatedly, every 2 seconds or so…..when it goes out, a spark then occurs between 2 contacts and re-lights the flame.

Please may I ask whats wrong?

The Gas Engineer did come out and do the annual check on it a few months ago, and said it was fine

 

[Deleted member 120897]

Could be a multitude of things, best getting an engineer out. Boilers can breakdown anytime, even the day after!

 

[boilerboy22]

Could be a multitude of things, best getting an engineer out. Boilers can breakdown anytime, even the day after!

Thanks, do you think it might be something to do with the fact that i was out of the flat for 2 months, then when i returned, it had started doing this.....do i need to equalise the gas pressure or something?...something to do with the little dials on the unit?

 

[boilerboy22]

In relation to the above, does anyone have a good youtube video for how to increase the pressure in a gas combi boiler?......i did it years ago, in a different flat, but cant remember it.....you twiddle the gas pipe tap till the pressure reading on the boiler goes up, or something....does anyone remember it? I think that might be my problem here?

 

[Nwalky]

In relation to the above, does anyone have a good youtube video for how to increase the pressure in a gas combi boiler?......i did it years ago, in a different flat, but cant remember it.....you twiddle the gas pipe tap till the pressure reading on the boiler goes up, or something....does anyone remember it? I think that might be my problem here?

Hi there, as stated above, it could be a multitude of things causing this issue but the fact that it is your bath that is giving you the issue then i would first try running the hot bath tap slower.

A combi boiler heats you boiler instantaneously which means that you need to give it time for it to heat the water. If you have your bath tap open full then the water will pass through the boiler too quickly and it will not be able to heat it, slow down the flow rate of the water coming out of the tap and see if the boiler is then able to heat it adequately, a common downside with combi boilers is the amount of time it can take to fill a bath with adequate hot water within a reasonable timeframe due to the maximum flow rate that the boiler can supply.

Other than what i have described above, it could be something as simple as a stat within the boiler telling it that it is overheating or if the boiler has a plate heat exchanger then it could be choked, causing the boiler to cut out and reignite on and off because the water is not able to leave it fast enough, thus causing it to overheat and cut out.

Looking at the photos your boiler does not need to be topped up, do not tamper with any gas vales on the boiler as this has nothing to do with the issue and you should contact a competent enginner to resolve any issues other than you trying to run your bath slower

 

[boilerboy22]

Thanks, though in this video...
Boiler pressure
...it says that if pressure is less than 1 bar, then you must re-pressurize it....problem is, i copied what he did, with the two valves on that silver pipe thing, and nothing happened....do you know whats wrong?

The gas flame is still going out and re-igniting repeatedly.....sometimes turning the flow rate down does help.....but the best way i find, is to turn the temperature right down at first, whilst running the bath, and then it eventually keeps the gas flame lit permanently, then i turn the water temperature up to get the bath water hotter.

...but as discussed, it always keeps going out when i first start running the bath.....this morning i had to turn the boiler on and off repeatedly, then press reset button, before the flame would actually light at all....then when it eventually lit, it kept going out , until i did the above action thing.

There are other valves it seems on the pipework, maybe i need to open those aswell......i will have to go and buy some pliers, as mine are at work, with all my other tools.

 

[fowlerboi]

The pressure you're talking about is your heating water pressure that goes round your radiators. The boiler uses this water to indirectly heat the tap water, it has nothing to do with gas pressure.

The fact you sound so brazen about playing with the boiler with almost no knowledge is dangerous. Please get an engineer to sort it for you, this is not a DIY fix and some of the things required would be illegal for you to do. The fact you're in a flat also makes any medaling dangerous for everybody else too.

 

[boilerboy22]

The pressure you're talking about is your heating water pressure that goes round your radiators. The boiler uses this water to indirectly heat the tap water, it has nothing to do with gas pressure.

..Thanks, i am wondering if we can keep the pressure high (above 1 bar) by turning off the valves to the taps and radiators?.....we never use radiators or hot tap water...like most, we cant afford it....in winter, we wear thick coats in the house, and in bed too....we do not heat the flat......so the question is, why might the water pressure be going low?...presumably a little leak somewhere?

And the silver pipe thing....it doesnt raise the pressure when we turn its 2 taps.....there look to be other valves on that same pipework....do you think they must be closed, and we need to open them?

We shouldnt report it...the landlord will likely decide he needs to renovate the whole flat, as well as the boiler , and will kick us out so he can do this. We are fully payed up in rent, but its too dangerous for us to report this....if we loose this flat, we loose our jobs...if we loose our jobs, we become homeless.

All i am wondering is how to make the pressure go above 1 bar...(and then also, how to stop the gas flame going out of course) i have done this before on other boilers....and people at work tell me its a simple thing to do...i even watched my old landlord do it in a previous flat....it was simple...just opening the tap, and waiting till the needle went above 1 bar....its going to naff the landlord off if i ask him to come round and do that simple thing.