Boiler Low Water Cut Off

Devin

Hi,

I'm in the midst of a gut renovation. We've put in all new systems - we went to fire the boiler on Friday to get the heat on (I live in CT) -- the guy who supplies my oil for the last ten years (he's been good to me on a couple of other things) told me he didn't want to fire the boiler because it didn't have a low water cut-off. I called the plumbers and they stated that they don't always put low-water cut-offs on their boilers (I find this hard to believe) and net-net that they could go with a mechanical cut-off vs one that's threaded in -- I checked the boiler in my current house and the low-water cut-off is threaded in and when I heard mechanical -- I'm thinking that means it will fail at some point -- I realize that they probably don't want to go the threaded route because it might require draining the boiler -- I'm really just looking for feedback from folks that understand this stuff as I definitely do not understand all this stuff (as I'm sure you could tell from reading this posting :-))

Thanks for the help.

johny

low water cutoff

A lot of places still do not require low water cutoffs.check thecode for your area.it is always best to have a low water cutoff.if you have aleak in the system somewhere the boiler doesn't know it and will keep on running and you suuure donot not want the boiler running dry.if your boiler is located above your piping you most definetly want a low water cutoff.if your boiler is located below your piping this is where you can get away from not having a low water cutoff,because if you have aleak above the boiler at least the boiler will not run dry.but you should still have a low water cutoff just to be on the safe side.better safe than sorry.

keith

Low water cut offs

are not an option. The only reason they are not standard equipment on water boilers is that the manufacturers don't want to be the 1st to up the price on their equipment. It is cheap insuarence for a safety hazard as well as boiler failure. They are a maintenance item wether you go with the mechanical vs. the electronic,both need attention.

Unknown

Keith,

They go in the piping above the boiler on a hot water system and are similar to a backflow preventer, in that local code requirements vary. They wire in before the boiler, like the remote switch (stair switch) and firomatic switch, and circuit breaker. Low water cutoffs aren't part of the boiler on a hot water system, they are part of the system and regulated by local codes.

That is changing in many places, now. Soon everyone may be using the same code.

Noel

Unknown

Keith

Noel is correct in that not all of the states or localities are requiring the use of a low-water cutoff on hot water systems. The cut-off device does want to be installed in the supply pipe above the boiler to ensure that a low-water condition never exists within the boiler. It would be desirable to always have the high limit bulb immersed in water and since is usually situated right next to the boiler outlet, the cut-off device would have to be higher. In most boilers, the only way it can remain higher is to be outside the boiler in the supply riser. The boiler manufacturers are not supplying these with the boiler in residential applications simply because only a handful of states are presently requiring them. The 1996 International Mechanical Code - Section 1007 does call for these devices to be installed, but not all states are enforcing it. Hope this helps.

Glenn Stanton

Burnham Corp.

JIM F.

LWCO LOCATION

I INSTALL THE LWCO IN THE END OF THE SUPPLY HEADER. ONLY SOME LOCALITIES IN OUR AREA REQUIRE LWCO. AS GLENN STATED IT IS IN THE INT. MECH CODE AS "ALL" BHOT WATER BOILERS SHOULD HAVE A LOW WATER CUT-OFF
JIM F.
MILFORD, CT.

keith

Point

Made regarding L.W. Cut offs and the local code enforcer requiring them. I do usually put them in the branch of a tee on the supply discharge. Would it not be safer to put the cut off on the hydronic boiler in the same tapping that is utilized on steam boilers rather than possibly installing the unit with none?I realize that it would be preferable to have them higher in the system to protect the boiler and circulator.

Unknown

LWCO Location

Hi Keith,

Once again, it would be best to shut the hot water boiler down before the low water condition ever reaches it. On steam boilers, the LWCO location is where it is to first of all protect from dropping below the lowest permissible water level and second to help maintain a steam water level in the boiler. The proper location should be in the supply main as close as possible to the boiler without a valve between the boiler and the LWCO. Hope this helps.

Glenn