feed and expansion tank

[freecountry65]

I have to re-site the f and e tank in the loft due to a loft conversion. Ideally I'd like to put it as high as possible just under the ridge, however there's very little room there now. What is the minimun height that the expansion pipe has to rise above the water level in the tank please?
thanks.

 

[ServiceNumpty]

Minimum height is 450mm, but also consider future maintenance, changing ball valve etc.

 

[45yearsagasman]

Normally 450mm or 18" in the old money is sufficient for most systems.

 

[Nige F]

Back in `87 I had to do a install with a low head setup - Vent was less than 18 inches for sure - probably a glow worm boiler - there was a set pattern / dimensions of pipework to follow . Possibly in the manufacturers instructions - then along came CORGI and cocked it`s leg on me . Any other old`uns remember this pipe layout

 

[DeltaT2]

Close connected Feed & Expansion pipes & correctly sited circulation pump for any system with low head.

 

[freecountry65]

If it's 450mm then it won't go under the ridge. Is there a minimum height that the f and e tank has to sit above the level of the highest radiator?

 

[Youllneverguess]

What boiler is it?

 

[DeltaT2]

Why not just 'seal' the system if your boiler has a high-temp cut-out??

 

[freecountry65]

the boiler is a glow-worm - badged as British Gas 330.

 

[freecountry65]

delta t2 - not sure hat you mean by "seal" the system. Do you mean pressurise it?

 

[45yearsagasman]

View media item 29821Do it like this and you don't have to worry about the vent pipe anymore.
Will work perfectly with your system.

 

[freecountry65]

delta t2 - thanks for getting back to me with the diagram. The suggestion you make would solve the problem I'm having - but doesn't combining the feed and vent make the system less safe?
thanks.

 

[Youllneverguess]

Not if the boiler has an overheat stat.

 

[45yearsagasman]

Quote:- delta t2 - thanks for getting back to me with the diagram.
Should've gone to Specsavers. Read the text and your boiler has o/heat protection.