Expansion vessel help please

[scazz33]

Hi guys

My old flexcon 8L 0.5 gas charge from 1998 was so heavy it was full of water now I don't know if that's faulty or not, I now brought a new zilmet 8L 1.5L

My old one was flexcon 8L 0.5 gas charge now my new one is zilmet 8L 1.5.

Is this going to be ok or not as now my boiler won't stay alight?.

thanks guys

 

[Justin Passing]

Your old opne might have just needed pumping up to get the water out.
There's some stuff in the FAQs about pressure vessels. If you read that you'll get the idea.

 

[scazz33]

Now my boiler keeps going off, it lights stays on for a minute and goes off and also the pressure keeps dropping.

 

[Madrab]

As was suggested in your previous post, I would recommend you get someone in to sort your system out, what you are attempting isn’t the easiest to DIY, it needs knowledge for that type of boiler, as it seems you are finding out.

Also, If the expansion vessel is down the right hand side of the boiler internally, then you really should be DIY’ing it all all TBH.

 

[bernardgreen]

then you really should be DIY’ing it all all TBH.

then you really should NOT be DIY’ing it at all

 

[Madrab]

Yup, I hate auto correct sometimes, it was mean to be “shouldn’t”

 

[scazz33]

At Madrab if you looked at my post you see that vessel is in completely different place to the boiler and ITS NOT internal, that means it's not inside the boiler.

 

[Harry Bloomfield]

At Madrab if you looked at my post you see that vessel is in completely different place to the boiler and ITS NOT internal, that means it's not inside the boiler.

Does the pressure drop, irrespective of whether the boiler fires, or not?

 

[Johntheo5]

Hi guys

My old flexcon 8L 0.5 gas charge from 1998 was so heavy it was full of water now I don't know if that's faulty or not, I now brought a new zilmet 8L 1.5L

My old one was flexcon 8L 0.5 gas charge now my new one is zilmet 8L 1.5.

Is this going to be ok or not as now my boiler won't stay alight?.

thanks guys

Generally, the EV will be installed with a pre charge pressure of 1.0bar, the system is then filled to a pressure of 1.5bar, cold. If the precharge pressure was (is) 1.5bar then the system should be filled to not more than 1.7bar as, depending on system volume then the hot pressure might reach 3.0bar and PRV lifting. Are you sure you havn't a pump problem?, you should see a slight rise in boiler pressure of ~ 0.3bar when the circ pump starts, is the boiler displaying a fault code like low water level?

 

[Madrab]

At Madrab if you looked at my post you see that vessel is in completely different place to the boiler and ITS NOT internal, that means it's not inside the boiler.

Didn’t see anywhere in the post where it says the EV is in a completely different place, hence why I said

If the expansion vessel is down the right hand side of the boiler internally

Even then, given the additional difficulties of pressure drops and the boiler shutting down prematurely, it still may be easier to get a professional in.