System or gravity.....

[Bunker]

Im planning an (oil) install on a large house, heating calc suggests 40Kw. Currently in there is a 20/25 outputting on 22mm only (used to be an old cottage but extended 15 years ago). Ill run 28mm out of the boiler as far as poss.

Question is, do I keep the gravity or cap it off and go sealed - Im nervous about pressurising an old system. I cant see the point of pressure testing as any damage is often found after time rather than straight away.

Also the f&e tank shows tide marks which do not reach the overflow which suggests that the system design must be ok?

Im mainly an oil boiler guy rather than a system designer so would value your experience here...

Tanks velly much.

 

[SimonG]

You mean open vented Bunker?

If its worked well open vented then keep it the same. I prefer to seal a system though, when I can.

 

[Bunker]

You mean open vented Bunker?

If its worked well open vented then keep it the same. I prefer to seal a system though, when I can.

Thats the ticket Simon, thanks.

 

[Ermintrude]

Deal and pressurise. It busts it burst. System will work 99.32 % better

 

[Best]

I take a careful look at all the pipework I can get at to see what the joints look at. If it looks good I consider sealing the system. Any slight weeps showing as stains on pipes out of brass fittings, I fix & replace any cheap or leaking valves. You don't need to have the system operating at very high pressure - 1 bar cold fill is more than enough for a 2 storey house. If plastic fittings, I would worry about them.
Make sure you use a decent powered pump, or consider having split circuits with 2 lesser powered pumps if the house has very long pipe runs or/and restrictive rads or undersized existing pipes.

 

[stevetheplumber]

Deal and pressurise. It busts it burst. System will work 99.32 % better

wow that means the last mexico i sealed is now running at 170% efficency
sealing a good system will make very little difference to its eficency and can cause loads of problems with tiny leaks needing the system filling .Especially on larger systems i always leave them open if i can

 

[Ermintrude]

Heats faster gets less sludge - open vent oxygen is dissolved via headder

 

[Whyme]

Put a split plate in if its a big house and flush what you can out the open vent side.