city supply line into hydronic system

[rrekih]

When after filling the hydronic heating system do you need to have the city supply turned on into the system?
Does the system use water and need refilling?
If you have a leak wouldn't it be better to let the system run down and shut down the system?

[Doherty Plumbing]

When after filling the hydronic heating system do you need to have the city supply turned on into the system?
Does the system use water and need refilling?
If you have a leak wouldn't it be better to let the system run down and shut down the system?

Yes you need to always have pressure in the system (12-17# cold). You need to install a boiler feed to maintain a constant pressure.

You don't want to let the water pressure drop to 0 because you're always going to have SOME evaporation in the system.

[msgale]

there a 2 schools of thought on this:
if you automatically refill your system, the homeowner may have a leak and it could remain undetected, with replacement water( with its own oxygen supply,which is bad) taking care of keeping sysyem filled.

if no auto refill,then a leak means your system pressure drops, and eventually the homeowner is aware there is a defect

[msgale]

When after filling the hydronic heating system do you need to have the city supply turned on into the system?
Does the system use water and need refilling?
If you have a leak wouldn't it be better to let the system run down and shut down the system?

normally a normal system loses a tiny amount of water, which you refill maybe once a month or so. if there is a leak, i think you are better off knowing about it.

otherwise a hidden leak could go on forever, with automatic refill ,and rot your joists etc,

[Doherty Plumbing]

there a 2 schools of thought on this:
if you automatically refill your system, the homeowner may have a leak and it could remain undetected, with replacement water( with its own oxygen supply,which is bad) taking care of keeping sysyem filled.

if no auto refill,then a leak means your system pressure drops, and eventually the homeowner is aware there is a defect

You could argue it either way really. But you were worried about it I'd suggest the person install an automatic fluid feeder.