[jpgalley]

Is it ok to shut off the main water supply into the house while on vacation and leave the heat on? Have an oil fired forced hot water system with a hot water tank that is heated by hot water from the furnace(has hot and cold inlets/outlets on top and heat water inlets/outlets on side). In other words does there have to be pressure available to the heating system at all times?

 

[NickTech]

yes and no....a boiler doesn't require a water supply constantly to operate. theoretically the water that fills the boiler should be the water in there forever...right? well of course we need to drain it and fill it during some service calls, or maybe a leak lets some out but the system does not "consume" water that would need to be replaced constantly. You do need pressure on the system but that is provided for by the expantion tank, not the inlet water pressure regulator. However if you were to shut the water off during your vacation...and the boiler should spring a leak.....and you do not have a low water safety shut off control (bulldog model etc)...then the boiler may run dry and possibly overheat and cause some serious damage.(the hi limit control won't shut it down in time if the water level is below the immersion well for the sensor.) These are very extraordinary variables for a less than likely scenario, but to give you a true answer it is plausible. Me?.....I'd shut mine down and have a good ol' time on vacation!!! :Thumbs: