Help with Older Radiant Heating System
We have an old radiant heating system that has hot water running through copper piping in the walls.
We recently had one of the pumps give out, so we replaced it after we drained the system. After replacing it, we refilled the system, but somehow air got in the lines. Is there any way to purge the air without having to purge all the water again?
Also, does the water fill valve to the system need to be open all the time while the system operates?
Thanks, I appreciate the help.
Well, you messed up when you drained the system to change the circ.
I know, you don't see valves to isolate the circ. There are ways to do it without valves.
With out seeing the set up, we can't tell you the best way to purge it.
The last thing you wanted, was all that fresh oxegen containg water going in to your system. Old pipes and fresh oxegen are a bad combo. Get a contractor in to purge it. It could take him a while.
Cross your fingers it doesn't spring a leak later this winter.
PS: Site rules, we're not allowed to give DIY instructions.
Given the age of your system it is important to have a hydronic specialist look it over. Cast iron boilers last an average of 35 years in domestic service and are often neglected because of this outstanding service. (The average forced air furnace lasts about 17 years).
Residential contractors unfortunately often neglect to put isolations valves at the circulator or even on the system! This is always a bad idea.
You should have your professional drain the system - which rarely has ill effects if done only when necessary - install a new pressure relief valve, boiler drain and microbubble reabsorber checking pH on refill. If installed correctly and in the correct order with isolation and purge valves, air will no longer be a problem.
Boiler work is not a DIY project.
Finally, you should be very careful about system water temperature as the plaster will come falling down if you exceed the maximum.
Last edited by BadgerBoiler MN; 12-21-2007 at 05:37 AM.
Please - make sure auto-fill water valve is always open- firing a dry boiler would be baaaaaaaaaaaaaad!
I hope this comment does not break diy rule
Age of system, and PH of fill of water vary enough that leaks can spring up no matter who does the draining and filling.
Originally Posted by BadgerBoiler MN
Isolation valves can be installed without draining the system.
Won't someone please close this DIY thread?