Boiler making banging sounds and pressure fluctuates

[flmmng]

Hi,

We recently moved into a new rental property and have had issues with the heating. The house has a Baxi boiler, and when we moved in it wasn't working, with an E119 error, but this was easily fixed by re-pressurising. However, about twice a week I need to re-pressurise again, so there must be a leak somewhere. But that is not all. What is worse is that the boiler will on occasion making some quite loud banging sounds, and the pressure will fluctuate qute a lot when it does this. I took a video, but it is too large, so here's a link to Google drive:
https://drive.google.com/file/d/1eCWwCu4_VaEr2xSp27ASVdE7J6dVrabN/view?usp=sharing

Besides the banging and pressure stuff, it also seems odd to me that the temperature is going up as the banging occurs, especially that it goes over 81C, when the water is set to 75C.

The hot water also seems to run out quite quickly. The landlord had an engineer in the other day, and he said the expansion vessel (I think) was empty and this was causing it, so he refilled it. I can't tell if it made a difference, only that it didn't solve it completely, as there sometimes could be days between this happening anyways.

So what could be causing this?

I should mention that the hot water system is quite complicated in the house, with a hot water solar system, and a connected coal stove in addition to the combi boiler. But the solar system is currently not working, and we haven't used the stove.

Any help or ideas is very welcome.


Edit: Fixed link, and bad wording

 

[Londoner2]

Best to hassle your landlord to get this fixed asap.

 

[flmmng]

Best to hassle your landlord to get this fixed asap.

Yeah, is trying to, but their gas engineer's solution is to turn down the TRV's a notch in each room, but it's not like we have a lot of heat on, no room has a setting over 3, and several have lower.

 

[flameport]

but their gas engineer's solution is to turn down the TRV's a notch in each room

That will archive nothing.

 

[Gasguru]

The boiler is probably boiling the water and the rapid rise in pressure causes the gauge to fluctuate....needs urgently looking at and the leak sorting.
Sounds like a weak pump/blocked filer/debris in the heat exchangers etc ie. nothing the user can do.

 

[flmmng]

The boiler is probably boiling the water and the rapid rise in pressure causes the gauge to fluctuate....needs urgently looking at and the leak sorting.
Sounds like a weak pump/blocked filer/debris in the heat exchangers etc ie. nothing the user can do.

Thanks for your input, much appreciated. Could any of these problems explain why it mostly seems to happen when the system was been off for a bit (i.e. after it has cut out due to need for re-pressurisation)?

 

[Gasguru]

Guessing here but hot water is less dense than cold water so easier to circulate.
Should be straightforward to diagnose...

 

[BlueLoo]

Yeah, is trying to, but their gas engineer's solution is to turn down the TRV's a notch in each room, but it's not like we have a lot of heat on, no room has a setting over 3, and several have lower.

Don't use these engineers again.

Clowns

 

[flmmng]

Guessing here but hot water is less dense than cold water so easier to circulate.
Should be straightforward to diagnose...

Yeah, that makes a lot of sense, thanks.

 

[flmmng]

Don't use these engineers again.

Clowns

Definitely, if it was up to me, but unfortunately the landlord picks the engineer.