QUESTION FROM ben

I have a gas furnace with hot water heating (one zone, single-pipe). All rafdiators in the house work. One relatively new baseboard heating unit does not - the pipe to/from this baseboard from the main supply pipe is only hot for 1st few feet and then cold rest of way to baseboard. The pipes to this were installed few years ago and run through an unheated crawl space in basement - is it possible that those have frozen and that is the cause. Have bled the baseboard.???

thanks

ANSWER FROM HOME-WIZARD

Dear Ben:

You mentioned that you only have one heating zone for your house, which serves all of the baseboard radiators in your home, right? So therefore for water to circulate through all of the baseboard radiators, the line can not be blocked (frozen) anywhere, from the beginning to the end. Unless, however, you have diverter valves before each section of baseboard radiator. If this is the case, then there could be a blockage in one section, and the water could be flowing around this section. This could especially be possible if there is a section of the line that runs through an unfinished crawl space. If you do have a section of the pipe where the water has frozen, you can read about methods for thawing out pipes on our "Baseboard Heating System" webpage in the question & answer section: http://www.home-wizard.com/maintenance/baseboardheating.asp

Hope this is helpful.
Home-Wizard.com

FOLLOW-UP FROM Ben

Its not frozen, but each radiator or baseboard has 2 pipes running to it off of the main section of pipe - so it is only to this one baseboard that the hot water isn't flowing - it's a long section (divertor) of pipe that runs through a crawl space to this. I bled it and let out a lot of water which was then replaced by hot water, but not completely - I'm trying again - copould there be a blockage (air) in that long pipe? - why wouldn't the water be flowing through that one section?

ANSWER FROM HOME-WIZARD

Dear Ben:

I'm trying to picture the configuration of your system from what you've described. and I'm not sure what you meant by it not being able to completely replaced by hot water when you were trying to bleed it. But if you are sure that the section is not frozen, there could be a couple of other reasons why water flow is being obstructed in this section of your baseboard heating system: 1) The diverter valve is stuck, and not allowing enough hot water to flow through the baseboard radiator section. If this is the case, then you will need to replace the diverter valve (unless you can give it a gentle rap to see if this will loosen it up). 2) This section of pipe could be "air-blocked." If so, then here is a webpage that describes what "air-blocked" is, and how to fix the problem: http://www.inspectapedia.com/heat/AirBleedValves.htm 3) There could be a buildup of sludge in this section of pipe. This could be difficult to fix, depending on how your piping is configured.

Hope this is helpful.
Home-Wizard.com