My upstairs is heated with hot water in the baseboard. The supply line and return line is PEX. The return line has frozen. How do I thaw the frozen return line. The lines themselves run through a well insulated attic. The supply and return lines run on top of the drywall below 2 feet of insulation.
My first concern is thawing the pipe, and next how do I prevent the pipe from freezing again.
thanks
Learn more about the pros and cons of single-room ERVs.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
A space heater to thaw out the line, not the fastest way, but it is a lot safer.
Is your heating system open or closed?
“A universal peace, it is to be feared, is in the catalogue of events, which will never exist but in the imaginations of visionary philosophers, or in the breasts of benevolent enthusiasts.” —James Madison
If I understand the question, the heating system is open. Meaning I can close off the heat to the upstairs and drain the water out without harming the rest of the system.
No, he is asking about how the heating system inter connects with domestic water.If it is properly isolated then you can put antifreeze in the heating system..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
The hot water in the baseboard is directly connected to my hot water heater, so I cannot put anti freeze in the line.
OK so it's part of the domestic hot water system--- that would be an "open" system.
I'm not a fan of open systems, basicly they are a breeding ground for bacteria.
To prevent future freezing--- a few things
Heat trace the pipe where it doesn't have protection from the elements.
Kepp the system flowing with the baseboards always calling for atleast a lilbit of heat during freezing conditions.
Or close it off from the domestic on a "closed " loop & put in antifreeze.“A universal peace, it is to be feared, is in the catalogue of events, which will never exist but in the imaginations of visionary philosophers, or in the breasts of benevolent enthusiasts.” —James Madison
In my utility room there are two lines which lead to the upstairs. One line supplies hot water to the radiators and one line acts as a return line. The supply line has a pump to puch the water through the lines. When the upstairs calls for heat, the pump turns on and the pipe gets warm. The return line does not get warm. I don't know for sure if the supply line or return line is frozen, but loop is clearly frozen since the return line does not get warm.
The return side does have a valve I could open which would allow be to drain the water out, but that would only allow water between the frozen part and the value to drain out. I would be left with water between the pump and the frozen portion.
Does anyone have any suggestions to thaw the pipe. It is located in a very hard to reach attic.
thanks
Rick.........
If you are not getting a return from the line, are you sure the water is not just going somewhere else? (that is, a separated line)
The supply and return lines for the second floor have no branches; it is a single loop. Thus when the return line is cold and the supply line is hot, I know the loop is frozen somewhere.
Water can't circulate if the pipe is frozen. No circulation means that the pump can't pump water upstairs; that means the pipe won't feel warm. Either your description is wrong or else you have a hidden water leak somewhere.
I'm not a fan of open systems, basicly they are a breeding ground for bacteria.
Are there places were code even allows open systems?
Well open systems are a strange thing when it comes to the code.
If every part of it is rated UPC then there is nothing in the plumbing code to forbid it.
If I wanted to run 5,000' of pex in my slab between the water heater & the fixtures, that actually meets code.“A universal peace, it is to be feared, is in the catalogue of events, which will never exist but in the imaginations of visionary philosophers, or in the breasts of benevolent enthusiasts.” —James Madison
The lines themselves run through a well insulated attic. The supply and return lines run on top of the drywall below 2 feet of insulation.
My first concern is thawing the pipe, and next how do I prevent the pipe from freezing again.
How do you know it's the return line that is frozen?
Beer was created so carpenters wouldn't rule the world.
How long has the system been in use?
There is a possibility of an air pocket, if this loop is the high point of the system.
Is there a paticular area that you suspect of freezing, the lines laying on the drywall under the insulation don't sound like they would freeze unless there was no heat at all in the room below them.
Rick,
Thanks for writing. Where are you located? If your having normal weather the water line should never be put outside the conditioned space.
I spray Icynene and Corbond foam insulation. One solution would be to spray the roofline with foam. Or you could simply make a foam board box or little tunnel over the heat lines and seal it to the ceiling below with expanding foam or caulk. Then put the loose fill insulation back over it.
If you don't mind I'm going to print out your story and keep it with me on sales calls to demonstrate how effective old type insulation is.
Stu
Just might want to hold off that until the problem is actually dechiphered and then solved. Might not be a frozen line at all.
I got lucky the weather in western Maine got above freezing and that combined with a propane heater I got the pipe thawed.
To answer some of the questions. The room below the pipe is heated and has 2 feet of blown in insulation. However the pipe was laid after the insulation was put in. The pipe has been in place for 8 years; this is the second time the pipe has frozen.
I have never had any trouble with air in the lines in the past, but the loop is at highest point.
The pump pushes the water up 1 story to the second floor, around two bedrooms then back down to the water heater. When the pipe is frozen if I open up a drain valve on the return line no water comes out.
Rick.........
So now while it has thawed I would be in the attic doing some remedial work on the insulation so it doesn't happen again. Clear the insulation away from under the pipe and ceiling below, box up and over the pipe in a manner that will allow some heat loss from the romm below to keep the pipe warm , then install insulation above and around the pipe.
I don't mean to question your knowledge, but iss it possible that you do have a closed system? Do you have an indirect hot water heater where boiler water circulates through a coil heating water in the tank? In such a system boiler water does not mix with potable water allowing antifreeze to be used.