Pipe size going into expansion vessel on sealed heating system

[Readingplumber]

Hi all, Ever since I was an apprentice plumber going back 20 or so years when we installed sealed heating systems - We always made sure that 22mm pipe would go into the expansion vessel ie do away with the actual fittings that come with it which were 15 mm and put our own 22mm female to copper adapters on the vessel.

But I am thinking say for 15kw boilers is this really necessary could i just connect it using 15mm pipe?
Thanks!

ReadingPlumber

 

[stevetheplumber]

15 will be fine most combis connect to the ev with small bore pipe

 

[oz-plumber]

Look at the connections of the expansion tanks in some of the boilers today.
I saw one today that had a 6mm pipe connected to the expansion tank, but generally they are 10mm pipe.
In old school terms 1/4" & 3/8".

 

[Ermintrude]

Some of the more reputable mfrs, heatline, vokea, biasi, feroli use an braded hose with 6mm internal dia when new! Would think the most important thing was to make sure the EV was of adequate size for your system!

 

[anz]

Some of the more reputable mfrs, heatline, vokea, biasi, feroli use an braded hose with 6mm internal dia when new! Would think the most important thing was to make sure the EV was of adequate size for your system!

Heatline, Vokera, Biasi, Ferroli.....Reputable?

Are you for real?

 

[mountainman]

Are you for real?

And the key turns!

 

[Ermintrude]

A touch of sarcasm! Only ever fit valiant, Baxi and ideal. Fix plenty of the reputable ones though. Wb installer but personally wouldn't fit one in a skip after doing repairs in the newer models!

 

[AWheating]

baxi are pants, ideal are okish, and vailant steal your customers........... id rather fit a WB. but each to his own.

 

[Ermintrude]

My main issue with wb is the amount of plastic and the ridiculous amount of room they leave you to work inside boiler? Wb rabbit on about ultrasonic welded hex ...... What about flow-turbines, and plastic hydroblocks that pinhole?

Why don't you like Baxi? Cheap and cheerful good service team and loads of room in case, parts are relatively standard? Duotec 1 is a pretty solid boiler along with mega flow? Obviously Bermuda is the daddy of all BB?