How to fit an external expansion vessel ?

[ChrisR]

What the hell is this one babbling about?

He's babbling about getting it right, so the thing works, really, in practice. We do all realise you don't see virtue in that.

 

[BigBurner]

Hi all, this is my 1st post so hopefully i have not messed up

my combi boiler expansion vessel is shot so i want to fit an external one .
The boiler has Pressure Relief Valve, filling loop and gauge so i'm assuming i can just plumb a new vessel in to the CH return without having to use another PRV, gauge and filling loop?

It will be fitted close to the boiler

It is a sealed system - using Baxi 105e combi

Help and advice greatly appreciated
Thanks
BF

The internal expansion vessel on the instant has two connections not one like most others. This has to be replaced.

The boiler expansion vessel incorporates about 10 to 15 litres of stored primary hot water, not fresh water. The hot water temperature in the vessel is maintained by the boiler to instantly heat the DHW plate heat exchanger when DHW is drawn off. The expansion vessel is a small thermal store.

If you have a large house with lots of rads an additional pressure vessel can be installed on the CH return. This will not increase the stored heat in the combi.

I always wondered why they never made the whole back panel of the combi a thermal store and give greater storage and flow rate.

 

[ChrisR]

The internal expansion vessel on the instant has two connections not one like most others.

Ah, BigDriveller has read the manual since his post 2 hours ago. Now he thinks he's an expert.

But he always gets something wrong.

This has to be replaced.

He's got that wrong. Leave it where it is.

 

[BigBurner]

He's babbling about getting it right, so the thing works, really, in practice. We do all realise you don't see virtue in that.

He said...Doing that will even give an extra hot "instant" storage capacity.

Adding an extra vessel will not give extra thermal storage capacity. The internal thermal storage expansion vessel has two connections. In short he hasn't much of a clue of what he was babbling about, as you don't either.

 

[ChrisR]

I, like Agile, found out how they work, tested and fixed them, years ago.
You'd rather pontificate after looking at the manual a couple of hours ago.
I suggest you do what we suggest, put temperature sensors in appropriate places, measure the effective volume of the heat store, and learn from that.
That approach might reduce the frequency of your sillier posts.

 

[BigBurner]

I, like Agile, found out how they work, tested and fixed them, years ago.

Agile clearly only has only half a clue of how they work, you are not far behind. BTW, I have no manual of this boiler. I believe, it is not made anymore.

 

[gas4you]

BTW, I have no manual of this boiler. I believe, it is not made anymore.

No, but you can easilt read one on your favourite place for info. The internet.

Making yourself look the fool you are again Drwaterburner

 

[ChrisR]

I have no manual of this boiler

That would account for your incorrect-by-incomplete posting of 11:30 this morning.

I believe, it is not made anymore.

That would be irrelevant, except as a failed distraction attempt on your part.

 

[BigBurner]

I believe, it is not made anymore.

That would be irrelevant, except as a failed distraction attempt on your part.

You still only had half a clue how it worked.

 

[gas4you]

Unlike you Drwaterburner, we do all work and have real experience of the products we advise on

 

[matt1e]

mmmm

What the hell is this one babbling about?

His CH expansion vessel is shot. He can cap the old off, and tee into the return near the boiler and fit another. It is so simple. Just put an in-line isolator valve to remove the vessel in future. Size the vessel to suit.

then later

The internal expansion vessel on the instant has two connections not one like most others. This has to be replaced.

not so simple after all apparently

I've got to respectfully side with the others here BB you did make a mistake here then you changed your mind

Agile clearly only has only half a clue of how they work,

same mistake you made on your first post
but at least

Surely the water in the EXPV is static and therefore its heat will not contribute to the system at all.

You may well be right.


Tony

at least Some people can hold up their hand
takes a big man etc

 

[BigBurner]

mmmm

What the hell is this one babbling about?

His CH expansion vessel is shot. He can cap the old off, and tee into the return near the boiler and fit another. It is so simple. Just put an in-line isolator valve to remove the vessel in future. Size the vessel to suit.

then later

The internal expansion vessel on the instant has two connections not one like most others. This has to be replaced.

not so simple after all apparently

Forgot it was the instant. That doesn't distract from the point the others only have half a clue.

 

[Deleted member 105431]

Half a clue is more than you have bigbull****!

 

[ChrisR]

You haven't made any point, All you've done is get it wrong and hurl abuse, as is your habit.

 

[BigBurner]

You haven't made any point, All you've done is get it wrong and hurl abuse, as is your habit.

If you mean me, I do not hurl abuse. You do, together with the other bathroom changers. And you didn't know.