Just wanting to check something RE: radiator re-fitting

JustAnotherSaver

Oh i've just remembered 1 thing that lad was telling me about ...

He was going on about pressurised & non pressurised systems.

This went over my head as i would've thought all systems would be pressurised to a degree? How else would the water flow from downstairs to upstairs surely if there was no pressure? And then when the water in the system gets hot, surely that is pressurised to a degree?

So how this relates to my situation i don't know. It just baffled me.

anotherbaldrick

A non pressurised system runs from a header tank in the loft, a pressurised system has no tank but is charged from the mains and then sealed. You need to know if you have a pressurised system because you will have to re-pressurise it when you replace the radiators.


Do not ignore what you has been said about the black slimy filth that will be the drainage dregs from the radiator, this will be left in the very bottom of the radiator after you have drained it and moving the radiator by lifting it will spill it out, it will be like a cross between creosote and ancient sump oil Often wondered if anyone did small rubber bungs to put in the union ends for when you lift the rad off ?


When draining the radiator down open the air vent valve at the top, this will tell you if the flow and return valves are fully turned off and will allow the water to drain quicker.

Lgas

Olives are the little brass rings that sit just inside the nut on the radiator tailpiece (the chrome part that is screwed into the radiator), they are also on the flow and return pipes between the nut and the rad valve, when you screw a nut onto a fitting, that is the part that seals it. I rarely use anything to be honest, and you shouldn't need anything with new olives, but PTFE is better than jointing compound/hawk white.