Leave valve to boiler on?

[CarbonNeutral]

On my oil burner I have a valve that controls fresh water supply into the forced hot water baseboard loops. Of course, it's a closed system, so in theory I should never lose pressure from the loop. but over a few months, it does drop off (mostly from the gaskets in the recirculation pumps). Do people usually leave this valve open? The benefit of keeping it closed of course is that if I have a leak/burst pipe, there is a limited amount of water that could ever be released.

 

[Jack Straw]

I was told to leave it open because if you do get a leak your boiler could run while dry and get ruined. That being said, I have a finished basement and would rather replace my 16 year old boiler than have to rebuild my basement. Maybe I'll go and close it........

 

[CarbonNeutral]

My forty year old boiler with some 20 year old parts... I feel the same. Perhaps I could just bill my insurance company for being a thoughtful houseowner? No?

 

[Gooserider]

Moved to boiler room as more appropriate...

Essentially the replies summarize the dilemma quite nicely - If you leave the makeup water valve on, then leaks can cause damage, especially "slow drippers" that might go for extended periods without being detected, or a major leak could cause a major flood... If you leave the makeup valve off, then a leak COULD result in water loss that could cause boiler damage.... However if you watch the system pressure, the fact that you are needing to add water would let you know that you need to find out WHY...

I would also note that it is possible to add a low water shutdown, or other safety features to protect the boiler, and that would probably be my first choice...

Gooserider

 

[sgschwend]

They may not have expansion tanks, if so, valve closed would be a problem

 

[Gooserider]

They may not have expansion tanks, if so, valve closed would be a problem

Don't know how you could have a system and NOT have expansion tanks, or be an open system... Code requires a backflow prevention valve on any DW fill valve connection, so even if the valve were open it STILL could not expand into the DW system - not to mention that you will also have a pressure regulator on that line to handle the fact that most DW systems are running much higher pressure than a boiler system. Normal boiler pressure is in the 12-20psi range, DW systems usually run closer to 50-80psi...

Expansion tanks are a totally different issue (however a failed bladder tank or a waterlogged air tank can cause problems as well, starting with the PRV valve letting go whenever the system fires - this will be aggravated if the fill valve is on.)

Gooserider

 

[Tony H]

I have my fill valve on but have considered installing a resettable meter to show if any water has been used . I do shut it down when the boiler is not running.

 

[stee6043]

I vote for leaving the valve OFF and fixing the leaks. I monitor my pressure quite regularly when the temps are static just to see if I have any reason for concern...

 

[Chris S]

I have been to several classes hosted by boiler manufacturers, trainers who advocate shutting the fill valve. From a contractors point of view, I do not want the liability of paying for the flood should something burst. Our installs should all be leak free, the low water cut off is for the boiler protection.
People with embedded tubing should be especially wary. I have a friend who had a leaking pipe buried under concrete- fill valve was left open, it ruined his boiler.

 

[CarbonNeutral]

I do have a newer expansion tank, they had replaced the older one that sits between the joists. There is also what I presume to be a back flow valve right after the cutoff. I'm pretty sure the leaks are just around the gaskets of the pumps, but who knows?

 

[drtnshtr]

Can someone post a pic of a low water shutoff valve? I think I may have one but Im not sure. I do have an expansion tank. I normally leave my water on but can see why I may not want to continue to do that.