Need some help with a forced hot water heat problem

[random_mail]

A contractor had to drain and cut part of my two-zone forced hot water baseboard heating system to do a bathroom remodel. He said he bled the lines, purged them of air, then refilled the reserve tank with fresh cold water.

Upon firing up the gas boiler, the system was loud and the upstairs zone was extremely slow to heat. He said this was because he couldn't get all the air out of the upstairs baseboards (said there were no purge valves) that the water had yet to heat up to the proper temperature. He suggested we let it sit overnight and try it again.

Today the noises are gone, but there is now no heat in either zone. One of the two circulation pumps gets quite hot, the other only tepid, but no heat flows into the baseboards

Any help would be appreciated!

[Edwin Pawlowski]

Probably air bound. Is there a valve (or two) that you can open to drain the system? Open it slowly and see if you get some air out. Often , it takes a couple of tries to get it all.

[RayV]

There *has* to be a bleed port to let the air out at the high point(s) of the system. On a ranch house I lived in the bleed valve was on the furnace because it was the high point. If you have searched every inch of the lines and can't find one call in a plumber.

I have found that after the initial bleeding of air it is good to run the system and bleed again and again and again. It just takes time to get it all out unless the system was installed *perfectly*.

I hope when you said "refilled the reserve tank with fresh cold water" you weren't talking about the expansion tank. They need to have a certain amount of air in them.

Was this guy a general contractor who plays a plumber on TV? Hot water systems can be very tempremental if not handled properly.

[random_mail]

Yes, that is my own ignorance in terminology...I meant that he re-introduced fresh water into the system.

[Jmilton]

water going through my hot water system gives of loud sounds of flowing water through the copper pipes. what causes this?

[Tekkie®]

Jmilton posted for all of us...

Air in system - google it next time.