Fitting External Exp Vess Instead Of Renewing Combi's

[youdontwanttodoitlikethat]

My ongoing saga with the broken exp vessel on my 7 yr old Vaillant Turbomax 824e has led me to the decision to leave the ev in situ, and add an external vessel. I have a few questions;

The boiler's ev is 10 litres. I can get 12 litre capacity ones, will this be ok?

The boiler's instructions say to pressurise ev to 0.75 bar. If the new external ev is 2 litres bigger, do I use same pressure?

I can tee the new ev 1.5 metres along the return from boiler. Is this close enough?

What connector do I buy to connect ev to 15mm pipe?

Many thanks
Fred

 

[matt1e]

hi fred
yes, better if anything
yes (may be easier to precharge it first)
yes, there will be fine

you will req a 15mm to 3/4 bsp female adaptor

Matt

 

[youdontwanttodoitlikethat]

you will req a 15mm to 3/4 bsp female adaptor

Matt

Is that same as a tap connector?

Thanks.

 

[compheat]

where is it fitted ?? is it in a cupboard or on show in the kitchen??

 

[youdontwanttodoitlikethat]

Compheat

In cloak room. Does it make a difference?

There's no way 'er indoors would allow a big red tank on her kitchen wall. But, what do women know?

Fred

 

[compheat]

Below the combi you should have a filling loop, if you drain the system and remove the non return valve you can fit a tee piece and then put the non return valve back on.
This will save cutting into the pipework, you can then get a 1m long flexi hose from B&Q 15mm compression to 3/4" swivel nut, this can then go from the tee piece to the expansion vessel and will save you messing about with rigid pipe connections
The EV comes pre charged so you wont need to alter the pressure

 

[Whitespirit66]

Below the combi you should have a filling loop, if you drain the system and remove the non return valve you can fit a tee piece and then put the non return valve back on.
This will save cutting into the pipework, you can then get a 1m long flexi hose from B&Q 15mm compression to 3/4" swivel nut, this can then go from the tee piece to the expansion vessel and will save you messing about with rigid pipe connections
The EV comes pre charged so you wont need to alter the pressure

Normally yes, but the Turbomax has a built in filling system, so not possible.

 

[Agile]

The EV comes pre charged so you wont need to alter the pressure

Anyone who believes that must work for BG !

Not that I should complain. I had a job a year ago to go and correctly pressurise one that BG had fitted and not bothered to check/reset its air pressure so just left it with 3 Bar and having no effect on expansion.

Others come discharged!

Every competent engineer will always check and set the pressure to that which is appropriate to the application.

Tony