-
Isnt that the overflow tank? (the smaller one, IANAPlumber)
-
As greenbank said - large one is probably your cold water tank, feeding your hot water system.
Small one is probably the header/expansion tank for your central heating.
Heating water makes it expand a bit and the way this is handled in older setups is to leave the system open to the air so that when the water expands in your pipework/cylinder/radiators it can just push up against the atmosphere.
This probably means your hot water pressure is dictated by the height of the larger tank as the water is basically falling from that height down through your system and out of your taps.
More modern systems tend to be sealed with a closed expansion tank, allowing mains pressure to pressurise the system and fewer critters and bits of debris to get into the tanks.
The opaque water suggests that it is indeed central heating water, which tends to get pretty foul even when you mix corrosion inhibitor into it. It's a closed loop so unless you actively drain and flush it, it just slowly collects gunk as it eats away the insides of your radiators etc.
You are reading a single comment by @moocher and its replies.
Click here to read the full conversation.
MTB-Idle
rhowe
@moocher
Oh, and another question
Why do I have two water tanks? The small one on the right contains opaque water :/
1 Attachment