Trying to get my head around domestic heating system

Pussyhands

This is just theoretical for my own understanding.

In a vented system where there's a cold water tank in the attic, I'm trying to figure out if it's the same pipe of hot water heating the coiled water tank and radiators?

When the water is heated by the boiler, does that one pipe with hot water split off to the coiled tank and also continue onto the rads?

If water is lost from the radiator, is there a water pipe from the cold water tank in the attic to the boiler?

DGOBS

Pussyhands

Does heat not travel up the cold water pipe?

youtheman

Pussyhands wrote: »

This is just theoretical for my own understanding.

In a vented system where there's a cold water tank in the attic, I'm trying to figure out if it's the same pipe of hot water heating the coiled water tank and radiators?

When the water is heated by the boiler, does that one pipe with hot water split off to the coiled tank and also continue onto the rads?

If water is lost from the radiator, is there a water pipe from the cold water tank in the attic to the boiler?

Answer to both your questions is yes.
1. radiators and cylinder are all piped in parallel. So the hot water feed from the boiler 'splits' several times for each radiator and cylinder.
2. If water is lost from the radiators then it is automatically 'topped up' by the feed from the attic tank.
3. some heat will make its way up the expansion pipe that has its overflow overhead the header tank. But under normal conditions there is no 'flow' through the expansion pipe (for emergencies or upset conditions only) so no big deal.