When I was a kid, every fall we would bleed the radiators to get the air out of the system. It stopped the pipes from banging AND made the system work more efficiently.

Now I have baseboard hot water heat and suffer the banging pipes. Our heating contractor says he can flush the system with a garden hose -- which I think just puts aerated water into the system.

I asked about vents -- what would you call them? -- and was told that it isn't done.

Is it? Should it be? Can it be? Can I do it? (I did all the plumbing -- CPVC, not copper, sorry -- in the house). And, can I use CPVC for baseboard hot water?

Thanks

David Fuller

CPVC in the heating system?? I have never installed baseboard heat, but I have worked on systems and I thought CPVC for heat was out of the question. Somebody correct me if I'm wrong.

Now, your question about bleeding the baseboards. Yes, you can install bleeders, but they cost money and so it isn't done much any more. If your contractor uses a pump and recirculates the water from the system, he won't introduce too much aerated water back into the system, but most don't go to that bother. I have done the garden hose method but I always feel guilty about that new water on the furnace heat exchanger. Maybe I'm worrying about something that doesn't matter. DON'T do this often, but I have already put a self piercing ice-maker valve into the high spot on a problem loop to bleed the air. I sure wouldn't want to see that trick all over a house!

If this is a recurring problem something else is wrong. Somewhere you have a leak. What should be done is have an "air scoop" or spirovent installed on the main supply out of the furnace. That would take care of any air that circulated past it. Then get the system full and it should stay that way.

EPM

It sounds like you need a tank installed above your boiler. The way we used to capture air in systems like yours was to install a valve that would begin to separate the water/air as it returned to boiler. The air would rise into a tank istalled between joists. You should have a valve to isolate this tank and a drain valve on the tank itself. This allows you to drain the drain as needed.this is not a traditional expansion tank. It is only to catch air in lines as they return to boiler. They sometimes fill with the heated water as well, but like you rauto radiator, they allow the water to return to system as it cools, of water is needed.hopefully you have an auot fill valve on this system...

To install bleeders on your system is not difficult but the room they need may be a problem. If your end caps allow for this - then in the areas you have problems of air entrapment is a good idea. The amount of air in the fresh water can produce a problem. But this is generally easy to remove via bleeder valves (vents). You can also consider a different return pump. Some are adjustable for flow rates.

I am an old copper man... never use pvc on boilers! I never warranty any type of cpvc installs. I have seen far too many nightmares occur with it at high pressures and over time. I have used the pex to great results however. It has been used and continues more today as radiant piping under concrete in slab houses, driveways etc,, it has been used to great success under floors with the proper reflecting panels under tradition flooring as well.