High make-up water needed in closed loop heating system

Dan_32

I have a medium sized 1.5MBTU commercal hydronic system with numerous under the slap copper runs. The home run loops as well as mono flow tees are under the slab feeding perimeter baseboard above grade in each of the rooms with thermostatic valves . By accident we found the system lossing water after a unrelated service call. To make a long story short we tried to determine and isololate each zone with elevated water pressure monitoring. All zones lost some degree of pressure. We tried visual, as well as IR cameria's scans, found none. We installed a water meter before the feed valve to determine the amount of make up water. To our surprise we are losing approx 250 gals per week and we still can't locate it! This is a church that is approximately 15 years old. We dont have any "as built" prints to aid us. Has any body else come across a simular case and can give us (me) some direction. Thanks, DS

clammy

been there

i have ran into this promblem over the years your best bet is if the leaks can not be located is to fiqure out how to re pipe these runs in question or sooner or later you will be replacing your boiler ,if you can isolate your underground loops i would pressure test them with nitorgen more stable inert gas temp /pressure doesn't change with temp unlike pressurized air ,if thermoter and run the zones boost up the temp but if the lines where insulated you may be out of luck .I still cannot fiqure out why guys still run under ground when faced with doing it i would usually use a trouth system like a drainage system and make a steel top cover for it then at least if leaks occur they can be fixed peace and good luck clammy

LarryC

Water loss

Cracked boiler? All of the water going up the stack?