Central Heating Pressure Vessel - Faulty or just 'gone flat'

[ianmcd]

unlikely to be a block in the vessel, will be where it is connected, the communication hose or pipe, post a pic of how it is connected

 

[Angelchops]

unlikely to be a block in the vessel, will be where it is connected, the communication hose or pipe, post a pic of how it is connected

Here you go, heating is currently on, The 2 bar reading has come up from zero when cold...

 

[ianmcd]

Release the water pressure from the system, remove the air pressure from the vessel, then disconnect this nut, blockage is in there, do not attemp to clean it without completely releasing all the air pressure, take the schraeder valve out and remove the vessel if you can, clear all the crud , then pump up the air side before refitting the vessel, also check upwaqrds from the connection and make sure it is clear

 

[Angelchops]

Release the water pressure from the system, remove the air pressure from the vessel, then disconnect this nut, blockage is in there, do not attemp to clean it without completely releasing all the air pressure, take the schraeder valve out and remove the vessel if you can, clear all the crud , then pump up the air side before refitting the vessel, also check upwaqrds from the connection and make sure it is clear

OK you sound confident Ian, I'll give it a go. Will likely be next week before I get the chance though now.

Just for the avoidance of doubt you're talking about that blanking nut right underneath the gauge, the one with the white paint on it?

Thanks again btw, this is much appreciated.

 

[ianmcd]

No the 3/4 brass nut that connects onto the vessel, this will allow the vessel to be lifted out for inspection and cleaning , not a big job to do, you will be surprised bow cruded up it will be in there, and as already said have a poke upwards to make sure that is clear too

 

[Angelchops]

No the 3/4 brass nut that connects onto the vessel, this will allow the vessel to be lifted out for inspection and cleaning , not a big job to do, you will be surprised bow cruded up it will be in there, and as already said have a poke upwards to make sure that is clear too

Hi Ian,
An update... I removed the vessel yesterday, which was a very simple and straightforward task. The weight of it, full of water, was quite a shock! I'm amazed the wall bracket hadn't failed. Anyway there was actually no blockage the water tipped out unimpeded and the adjoining pipework was also completely clear. When empty, however, I still couldn't get any air into it even with the Schrader valve removed. I pushed an Allen key through the valve hole and could feel the rubber of the diaphragm, it was stuck hard to the vessel on the inside. I think the vessel must have failed a very long time back due to lack of maintenance and I hadn't noticed.
Anyway I duly fitted a new one and everything is fine. In fact it's better than fine, it's like a new system. The pressure, hot and cold, is spot on and the system is running more quietly and more efficiently than I ever remember. We live in a 150 year old house and I'd always regarded the knocks and gurgles in the radiators as one of those things you get in old houses, but they're gone now. It's runs quietly and the house is warmer too. Brilliant!
A big thank you Ian for giving me the confidence to tackle this job, I really am delighted with how it's turned out.

 

[ianmcd]

Glad you got it all sorted, yes the membranes sometimes do stick if they have been left flat for long periods of time, but as you have found out they are not expensive and easily enough changed, just check it properly every year and it will be fine, and yes totally agree , a proper sized and charged vessel makes a huge difference to a system, probably the most under looked component on any sealed system