Why does this require cold water:

icesailor

Is there a specific reason why this feeder/LWCO has a requirement for cold water only to feed it with a maximum temperature of 120 degrees?

I will have to explain to someone why it is and isn't allowed and reasons for it. The fact that the manufacturer says it is so is fine with me. Others may not be so open.

Thanks.

Is there any reason that this can not directly feed a commercial steam boiler?



<a href="http://documentlibrary.xylemappliedwater.com/wp-content/blogs.dir/22/files/documents/2011/04/61.pdf">http://documentlibrary.xylemappliedwater.com/wp-content/blogs.dir/22/files/documents/2011/04/61.pdf</a>

Hap_Hazzard

What kind of water feeder is this?

When I was installing my water feeder (a Hydrolevel VXT) I thought about connecting it to the DHW line but decided against it after finding the specs on the valve they used in the water feeder.



The valve is a DEMA P442, and it has plastic valve seats. The maximum temperature ratings are 180° fluid, 120° ambient. I thought that was too low for comfort, so I went with cold water.



At about this same time I happened to read one of Dan's old articles about a boiler flooding issue he'd investigated. The cause turned out to be that the water feeder was connected to the hot water supply, and a piece of hard water scale, of the kind that typically forms when water is heated, had gotten stuck in the valve and prevented it from seating.



So there are two potential reasons. I'm not sure if either one is relevant to your situation.

icesailor

Makes sense:

Makes sense to me.

It is  McDonnell-Miller 51-51S combination LWCO and feeder.



Like I said, I didn't install it. I'm just trying to fix it.

The system works fine. It is a closed system and uses very little water. The day the inspector was there, a 2" high pressure hose was connected to the supply so as to put a load on the boiler and run outside. It still would run up to 12#. It added water then. I think that the inspector thought it always ran that way. It isn't.