feed and expansion tank but no vent??

[apcdave]

Hi fellas,

At a house yesterday - had to drain down central heating system ( oil fired ) , to replace circ pump/ pump valves and 2 port valve. After refilling system had a serious problem getting heat into the downstairs rads - it was when trying to clear a poss air lock that I discovered there was no vent over the f and e tank. Normal vent from hot water cylinder over the 50 gallon tank but definitely no vent for heating system. Got things going by back filling system and letting air out of joint at hot water cylinder but first time I have seen this and wondered if anyone else has come across this……..

cheers

dave

ps definitely no automatic air vents elsewhere either

 

[Irish]

close coupled f and e by the sounds of it

 

[Killy Bing]

close coupled f and e by the sounds of it

you're thinking of combined feed and expansion where you just run 22 or 28 to the tank

close coupled is the standard set up

combined comes in two variants
one where you just connect directly to the bottom of the tank
The other where you tee into the feed and make a vent from there

 

[apcdave]

combined feed and expansion? please explain king billy

 

[Killy Bing]

Here you go

Edited my last post with more info
Pic here

 

[Chalked]

Combined feed an vent systems are generally a pig to fill.

 

[Irish]

you're thinking of combined feed and expansion where you just run 22 or 28 to the tank

close coupled is the standard set up

combined comes in two variants
yeah that's what I meant
one where you just connect directly to the bottom of the tank
The other where you tee into the feed and make a vent from there

yeah that's what i meant it's a Sunday not on top of the ball sorry Killy

 

[Killy Bing]

yeah that's what i meant it's a Sunday not on top of the ball sorry Killy

ey don't apologise, with the thousand odd plumbing terms tis easy to get things mixed up

had a drink last night Irish? Haha

op when i come across them if there isn't a manual air vent on the coil if its easy i tee one in, i hate backfeeding

 

[Fishling]

Saw one like this yesterday so is it ok to leave like this as it can still feed back into the tank

 

[GasmanxxxR1]

Combined feed an vent systems are generally a pig to fill.

But less air issues once filled, most open vent systems i fit from new, i do it like this

 

[Mike Jackson]

Saw one like this yesterday so is it ok to leave like this as it can still feed back into the tank

As long as the boiler has an over heat stat.

 

[apcdave]

Thanks chaps - a new one on me. This sort of arrangement is thankfully not too common round these parts

cheers dave

 

[Killy Bing]

Thanks chaps - a new one on me. This sort of arrangement is thankfully not too common round these parts

cheers dave

if you come across one don't be tempted to change it.

usually changed to combined if the system has issues with pumping over or drawing air in

 

[happyflyer]

But less air issues once filled, most open vent systems i fit from new, i do it like this

A will never pump over and well said Killy never alter it, most of these did have a combined Feed and Vent pipe teed in just under the tank and then some smart bum decide they wanted a separate feed and expansion and the fun started.