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I plan to add a radiator into my attic room and run it off the 1st floor central heating loop. It will be a smallish rad. Is there any reason I cannot just add it onto the end of the existing loop - My main concern is whther the addition height will cause problems.

Thanks

Hiya,

I can't see there being a problem, if you have enough water pressure to fill your system already and your boiler output is sufficient to take another radiator (total output of rads must be less than or equal to total output of boiler) then adding an extra rad should be fine, just T in. You may need to throttle the lock shields a little to get the balance right to force the hot water up there.

It depends on the type of system you have..........



htg

The system is conventional boiler with hot water cylinder.

Thanks

The F&E tank will have to be sited above the radiator you add to the attic.

Then the vent pipe should be 18" above the tank - is there room ?

Also it may be possible you will have to update the pump, and possible get a 6m head pump rather than 5m, best way to find out is to try it with the existing pump first.


Htg

Htg engineer, just out of interest why does the vent pipe need to go 18" above the F&E tank? Presumably it's to allow for expansion when the water gets hot. However, water will equalise level between the tank and the vent pipe. I would have thought the critical issue here would be to allow sufficient space in the F&E tank between the water level when cold and the overflow outlet from the tank and that, provided that the vent pipe goes over the top of the tank and it's open end is higher than the overflow, it would be OK.

The minimum recommended height is 450mm.

Recommended calculation to determine the open vent height :

150mm (vent height required above tank water line) + 40mm per metre of system height.

450mm = 17.7" (18"ish)

It allows for expansion, but also the extra height will prevent pumping over and air being drawn into the system via the vent pipe, as does the position of the pump and the cold feed.

htg

Thank you for the information Htg Engineer.