F and e pumping over

[simond]

Modern boilers have a higher resistance to the water flow so the close coupled method is best.

Follow 45 years for the answer.

 

[Scotty 890]

Thanks everyone for your reply's...45yearsagasman thanks for your drawing I could put the pump in the airing cupboard the only thing is I have the down stairs return T'd in after where it says in the drawing there should not be any more is there another way around this without pressurising as I may want to put in a back boiler aswel as oil heating in the future

 

[dilalio]

Nope... You're dealing with hydraulics! The solution is in the pipe runs. You can always seal it up for now but leave provision for an F&E, if required in the future!

 

[Agile]

Although the pump is better on the flow, it would still work if you did the 45 modification but just left the pump on the return for the time being.

Tony

 

[Steelmasons]

Although the pump is better on the flow, it would still work if you did the 45 modification but just left the pump on the return for the time being.

Tony

Oh dear....
Depending on static head the system could be subjected to negative pressures and hence causing air to be entrained (circulator on return)..
A prime example is when circulator is running no water or air is discharged from radiator bleed pin , switch circulator off and radiator can be bled.
Basic hydronics Tony....system design is not your strong point.

 

[Scotty 890]

So the feed and vent can only be as much as 150mm apart but Does the feed and vent have to tie in on a horizontal piece of pipe like in the drawing I understand I can take the vent from highest point but would the feed be ok vertically T'd in

 

[DP]

I decided then to close the valve coming out of the f and e tank feeding the heating circuit and the water coming from the vent

LOSE the valve NOW before you damage the boiler

 

[Gasguru]

A common arrangement for the close coupled setup is to arrange the pipe work as an H pattern. Eg. Your flow from the boiler would be the left lower connection (on our H), upper left is the vent, upper right the feed and lower right continues to the pump. This setup also has the advantage that it places most of the system under positive pressure reducing the ingress of air. The feed and vent is the neutral point in the system and the short run to the pump is under negative pressure. The H can be formed from a couple of t fittings with the branches joined in close proximity.

 

[Scotty 890]

Thanks for your reply's...dp the valve was only put in for future draining down it's a full bore gate valve on the feed to the heating system from the f and e shouldn't do any harm...if I was to pressurise the heating system for the time being until I decide to put in the back boiler could I just put the expansion vessel anywhere on the system (eg in the attic) or does it have to go flow from the boiler before the pump aswel

 

[flameport]

the valve was only put in for future draining down it's a full bore gate valve on the feed to the heating system from the f and e shouldn't do any harm

When draining, valves are opened. There is no reason to have a valve where you have put it.

If it was closed the system water will not be able to expand into the F&E, but will instead expand up the vent pipe and spill over into the F&E. When it cools, air will be drawn in through the vent and circulated through the system which will cause corrosion.
Anyone attempting to bleed radiators to get rid of the air will make this problem worse, as no water will be added.
If the water level drops further due to a leak or excessive bleeding, the boiler will be damaged or destroyed.

 

[Scotty 890]

I understand the valve has to b open to feed the heating system and can't b turned off I just think it is handy for maintenance...if I was to change the system to a pressurised system could I put the expansion vessel in the attic as long as there is no valves between the boiler and the vessel and keep the pump on the return as is