Advice on external expansion vessel.

[Vic Rattlehead]

Hi all,

The expansion vessel on my Baxi Combi 133he plus has died (water from the schrader valve) and I want to fit an external vessel, teed into return pipe via the filling loop.

I'm confident at doing the work as have good DIY skills and plumbing knowledge but my wife is scared that it's a prosecutable offence for me to do so like with tampering with the gas supply/side of the boiler.

I have explained that I'll not be going near the gas side and not tampering with the inners of the boiler and that fitting an external vessel is generally a more cost effective solution that replacing the internal one. But as nowhere really says "it's ok to this/that" I'm struggling to convince her.

So in your opinion, am I doing something illegal by fitting my own external expansion vessel?

Apologies for the post but I'd just like some professional opinion on this and any advice would be greatly appreciated.

Cheers

 

[Chalked]

How ate you going to cap off the old one without going into the boiler?

no probs fitting one outside the boiler after that.

 

[Resolute]

Already broken the regulations by removing the boiler case to check the existing expansion vessel!

 

[Ermintrude]

Don't need to cap old one it's full of water as bits if rubber. Perhaps some one told him ( GSE)

Yeh external one fine fit a suitably sized on (depends on volume of your ch system)

Don't forget inhibitor, why not keep your wife and family safe by getting boiler serviced by a gas safe engineer?

 

[Vic Rattlehead]

Thanks,

Boiler has been regularly serviced. Had a new diverter valve top and bottom earlier this year and a combustion chamber seal year before that.

Advice from my cousin who is GS registered was the boiler was ok for another couple of years and just have the part replaced.

 

[adam brennan]

Hi all,

The expansion vessel on my Baxi Combi 133he plus has died (water from the schrader valve) and I want to fit an external vessel, teed into return pipe via the filling loop.

I'm confident at doing the work as have good DIY skills and plumbing knowledge but my wife is scared that it's a prosecutable offence for me to do so like with tampering with the gas supply/side of the boiler.

I have explained that I'll not be going near the gas side and not tampering with the inners of the boiler and that fitting an external vessel is generally a more cost effective solution that replacing the internal one. But as nowhere really says "it's ok to this/that" I'm struggling to convince her.

So in your opinion, am I doing something illegal by fitting my own external expansion vessel?

Apologies for the post but I'd just like some professional opinion on this and any advice would be greatly appreciated.

Cheers

No , your ok to do it as long as you are not tampering with a gas appliance, or gas supply. Get a large capacity expansion vessel (12lt or more) , tee in to return near the boiler. Done in 22mm . Keep the run as short as possible .

 

[Billy Bob Bob]

No , your ok to do it as long as you are not tampering with a gas appliance, or gas supply. Get a large capacity expansion vessel (12lt or more) , tee in to return near the boiler. Done in 22mm . Keep the run as short as possible .

why keep the run in 22mm? this is totally unnecessary,but i agree on a 12L EV

 

[adam brennan]

why keep the run in 22mm? this is totally unnecessary,but i agree on a 12L EV

15mm will work. But 22mm is preferable. Allows for easier expansion through a less restricted pipe I suppose?

 

[SafeGasInstall]

Listen to the wife for once

 

[chris watkins]

15mm will work. But 22mm is preferable. Allows for easier expansion through a less restricted pipe I suppose?

You haven't had a look inside too many combi's or system boilers then Adam & noted the 10mm copper connection to the vessel ? The rate of expansion is such that 15mm will be fine.
How we can be saying with some certainty that 12L vessel will do, is a worry, how big is the system? i.e. what is the water content ? Where is the boiler / expansion vessel to be located ? What is the cold fill water pressure going to be ? What is the selected vessel charge ?
These are the things that a heating engineer would be considering when selecting the right size & set-up for a replacement external expansion vessel.
It is this knowledge that you would (should) be paying for if you employed one Vic !!

Happy to help you fix your own but please find out the whole story otherwise things can & do go very wrong.

 

[Reg Man]

Just going to through a spanner in here. Don't know the answer my self but hear goes. On a normal open vented system you can not have a valve between the boiler and open vent/cold feed as this is the method for expansion in the system (fact). So if you have a combi say, on a sealed system the expansion vessel serves the same purpose. So you make the boilers internal expansion vessel redundant and fit an external one, should you remove the boilers flow and return isolation valves, because your not allowed a valve between the boiler and the expansion?

 

[chris watkins]

Just going to through a spanner in here. Don't know the answer my self but hear goes. On a normal open vented system you can not have a valve between the boiler and open vent/cold feed as this is the method for expansion in the system (fact). So if you have a combi say, on a sealed system the expansion vessel serves the same purpose. So you make the boilers internal expansion vessel redundant and fit an external one, should you remove the boilers flow and return isolation valves, because your not allowed a valve between the boiler and the expansion?

But you do still have the pressure relief (= the Safety Open Vent Pipe) ? Plus can you run the boiler with the valve/s closed ?

 

[Reg Man]

So one safety device down but last resort is the PRV? Fair comment for debate.

 

[chris watkins]

So one safety device down but last resort is the PRV? Fair comment for debate.

Only the same as a blocked cold feed or a frozen SOVP but hopefully not at the same time.:bomb2:

 

[oz-plumber]

RE: Original Post.

Why was the diverter valve changed?

Was that to solve the issue or was that a different problem.

If the Plumber changed the diverter valve and the said the problems was the expansion tank, I would be questioning the Plumber.

 

[Vic Rattlehead]

RE: Original Post.

Why was the diverter valve changed?

Was that to solve the issue or was that a different problem.

If the Plumber changed the diverter valve and the said the problems was the expansion tank, I would be questioning the Plumber.

DV was shot and was replaced. Rads would become hot when DHW was used.

 

[SafeGasInstall]

But you do still have the pressure relief (= the Safety Open Vent Pipe) ? Plus can you run the boiler with the valve/s closed ?

yes its there but how often they actually work ? Not arguing Chris as I have seen many and I am sure you have seen many too that are not operating when they should

 

[Billy Bob Bob]

You haven't had a look inside too many combi's or system boilers then Adam & noted the 10mm copper connection to the vessel ? The rate of expansion is such that 15mm will be fine.
How we can be saying with some certainty that 12L vessel will do, is a worry, how big is the system? i.e. what is the water content ? Where is the boiler / expansion vessel to be located ? What is the cold fill water pressure going to be ? What is the selected vessel charge ?
These are the things that a heating engineer would be considering when selecting the right size & set-up for a replacement external expansion vessel.
It is this knowledge that you would (should) be paying for if you employed one Vic !!

Happy to help you fix your own but please find out the whole story otherwise things can & do go very wrong.
View attachment 15935

its easy to deduce a 12 L WILL WORK,THE BAXI 133 IS NOT A YOUNG COMBI,ITS 10l ONE HAS WORKED FINE UNTIL ITS FAILURE MANY YEARS FROM WHEN IT WAS FITTED THEREFORE 12l WILL CUT IT

 

[Killy Bing]

its easy to deduce a 12 L WILL WORK,THE BAXI 133 IS NOT A YOUNG COMBI,ITS 10l ONE HAS WORKED FINE UNTIL ITS FAILURE MANY YEARS FROM WHEN IT WAS FITTED THEREFORE 12l WILL CUT IT

have a snickers gas man.... [video=youtube;L4mP9pR-mzU]http://www.youtube.com/watch?v=L4mP9pR-mzU[/video]

 

[Kev the gas]

its easy to deduce a 12 L WILL WORK,THE BAXI 133 IS NOT A YOUNG COMBI,ITS 10l ONE HAS WORKED FINE UNTIL ITS FAILURE MANY YEARS FROM WHEN IT WAS FITTED THEREFORE 12l WILL CUT IT

Very dangerous game to presume the system is the same as when it was installed, and was it installed / sized properly in the 1st place ????

and then again has our intrepid Diyer fitted. New loft conversion/ under floor heating in his Wickes conservatory ???

Maybe we will never know

 

[Billy Bob Bob]

Very dangerous game to presume the system is the same as when it was installed, and was it installed / sized properly in the 1st place ????

and then again has our intrepid Diyer fitted. New loft conversion/ under floor heating in his Wickes conservatory ???

Maybe we will never know

carry on then,after all its not like i have been doing this for 5 minutes

 

[Kev the gas]

I wasn't having a pop Gasman, but dodgy to presume.
The install, I was working on this week had Artex on the ceilings, big lounge.
The client didn't want overboarding so the ceiling was pva'd twice, a coat of bonding and two sets of multifinish both had pva before each coat.
I was hanging a rad and left the room to get some fittings, all of a sudden 100 kg of plaster fell down, if a small child was underneath it ??


It turns out the Artex was pasted on top of wallpaper, the extra weight of the plaster ripped the paper off!

 

[Billy Bob Bob]

I wasn't having a pop Gasman, but dodgy to presume.
The install, I was working on this week had Artex on the ceilings, big lounge.
The client didn't want overboarding so the ceiling was pva'd twice, a coat of bonding and two sets of multifinish both had pva before each coat.
I was hanging a rad and left the room to get some fittings, all of a sudden 100 kg of plaster fell down, if a small child was underneath it ??


It turns out the Artex was pasted on top of wallpaper, the extra weight of the plaster ripped the paper off!

based on what the op said in post 1,its presumed its the standard set up unless they say differently based on this a 12L would work fine

 

[Kev the gas]

Based on what customers tell me they get an awful draft through their air vent, so I don't need to check it then ??

Presuming and believing what people say is ???

 

[Billy Bob Bob]

Based on what customers tell me they get an awful draft through their air vent, so I don't need to check it then ??

Presuming and believing what people say is ???

i dont have a crystal ball,i have not seen it,its based on the op,s first post,if he gets it wrong,negates to tell us the size of the system and undersizes it thats his bad not mine,i based sticking a 12L because this boiler would have has a 10L originally yes it could be different to what they say but frankly as i am not doing the job,and have not seen it i dont care