Concerned with new 3rd floor HW zone freezing.

william_5

living on long Island levit houses had the same thing you are talking about after replacing pipes in one house i found the homeowner wrapped the pipes with elewrap it has a small heater in it that plugs into a 110v outlet (can be found at home depot)his wife pluged in one side but forgot the other side. one side was frozzen after i repaired the pipe he asked me if there was some way this could be done with out having to remember to plug it in on cold nights. I wired the ele pipe wrap to a hw RA89 with a ac- heating thermastat in the craw space. He has the thermastat set at 40 so when the temp goes below 40 it calls for heat closing the switch on the RA89 sending power to the pipe Wrap keeping the pipes warn

one way around a hot room
ps. its also used around oil lies on outside oil tanks
William

Al_24

How do I prevent my 3rd floor HW lines from freezing?

I currently have a gas hot water boiler feeding a three story home.

I recently installed two 4ft cast iron radiators in our remodeled 3rd floor bedrooms and ran a 3/4" supply and return line from the boiler in the basement up to the 3rd floor feeding the new radiators.

The new supply and return lines will have an independent circulator and thermostat strictly for the two 3rd floor bedrooms.

The lines are run up an interior wall; however, the problem is that when the two 3/4" lines make it to the 3rd floor, the lines terminate in a crawlspace on the 3rd floor.

The 3rd floor crawlspace is insulated but can get below freezing on really cold days due to the soffit vents.

My new HW supply and return lines in the crawlspace run aproximately 40 ft on top of the joist insulation before it connects to the radiators in the conditioned space.

I insulated my new copper lines in the crawlspace; however, I am still concerned of the potential for freezing when the thermostat is satisfied and is not moving any water.

What are my options???

I would rather not run a circlator continuously for obvious reasons.

I thought about adding glycol but I did not want the glycol to circulate through the old radiators on the first two floors due to the potential for leaks.

Heat trace is not an option I want.

The only option that I can come up with is adding a small heat exchanger on the new 3rd floor loop and put a small percentage of glycol to the new loop only. The heat exchanger would prevent any glycol from entering the main loop to the first and second floor old radiators and give me my freeze protection on the new loop to the 3rd floor.

I know it would work but it just seems overkill!!

Is there someone who has a better idea to help me from freezing my 3rd floor loop?

I appreciate any assistance.

Unknown

running a 3/4 \" line

Since u said that the new zone have their own pump and thermostat... Do u have the flo control valve on the zone? How many zones is this system?