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jc60618
12-13-2009, 08:21 AM
Am having a problem with my boiler. Its in a duplex house and it feeds cast iron radiators in the second floor only. The boiler fires up OK put the radiators dont get hot, just warm. In the basement the supply pipe is hot but the return lines are just warm. Ive checked the aquastat relay box and the temp in there is set to 180 (low) 200 (hot). Also the pump and reducing valve was changed two weeks ago. Can the problem be the circulation pump? How do I know if its working correctly? When the pump was installed I could feel the water reciculating in the pipes but not anymore. Is the boiler just heating up standing (convection) water and thats why the radiators dont get hot?. The pump is a series Taco 005 pump.

johnjh2o1
12-13-2009, 08:26 AM
It sounds like you have air in the system . Have you tried bleeding the radiators?

John

jc60618
12-13-2009, 08:54 AM
Whats the best way to start? Should I go to each radiator and bleed them out for a couple of minutes?

johnjh2o1
12-13-2009, 08:57 AM
Just do one at a time. Open the vent on each radiator until you get water.

John

jc60618
12-13-2009, 09:42 AM
Before I bleed the radiators I checked if the radiators were hot, five out of seven were indeed hot. I bleed them any way and I got a little air out of one, the rest water came out right away. Ive included an overhead drawing of the piping. Can the problem be with the pump is it "air locked" because I dont feel any movement in the return piping by the boiler.

johnjh2o1
12-13-2009, 10:05 AM
Turn the thermostat down then bleed the radiators. This will allow the air to go to the high points of the system which will be the radiators. You will not feel any movement in the return piping at the boiler.

John

jc60618
12-13-2009, 10:10 AM
When I turn the thermostat down should I wait for the system to cool down before bleeding the air out.

johnjh2o1
12-13-2009, 10:18 AM
No, just bleed the radiators.

John

Doherty Plumbing
12-13-2009, 10:33 AM
Am having a problem with my boiler. Its in a duplex house and it feeds cast iron radiators in the second floor only. The boiler fires up OK put the radiators dont get hot, just warm. In the basement the supply pipe is hot but the return lines are just warm. Ive checked the aquastat relay box and the temp in there is set to 180 (low) 200 (hot). Also the pump and reducing valve was changed two weeks ago. Can the problem be the circulation pump? How do I know if its working correctly? When the pump was installed I could feel the water reciculating in the pipes but not anymore. Is the boiler just heating up standing (convection) water and thats why the radiators dont get hot?. The pump is a series Taco 005 pump.

Sounds to me like your circ pump is acting up. If you don't have any leaks i the system or have never had any problems with air before I doubt it's air.

johnjh2o1
12-13-2009, 10:39 AM
He stated he replaced the cir. and the auto feed two weeks ago. That is more then likely where the air came from.

John

Doherty Plumbing
12-13-2009, 10:46 AM
He stated he replaced the cir. and the auto feed two weeks ago. That is more then likely where the air came from.

John

Ooops sorry sometimes I read through the posts so fast I miss those little tid bits of info :D

My bad.

jc60618
12-13-2009, 01:41 PM
Thanks guys I think that solved my problem. I have heat on the two radiators now. By the way how can I tell if the pump is doing its job. The manufacturer of the pump says its real quiet when operating. Also what are some of the common malfuction of circulation pumps. Can something get caught in the impeller preventing it from moving? Finally what does the impeller "spin" is it water or steam? I have gotten different responses from two heating guys?

jadnashua
12-13-2009, 01:55 PM
It sounds like your system is hot water...if it had steam it wouldn't need a circulator. So, the circulator is moving water.

Peter Griffin
12-13-2009, 02:05 PM
You can usually hear the circ running. Is it installed with the direction of flow correct? Is it wired correct? If it's running, you have an air problem or not enough pressure. Pressure should be 12 - 18 lbs

rmelo99
12-13-2009, 03:18 PM
My system has many circulators and it was tough to tell when a pump was running. They make a slight humm. I was told to take a screwdriver and touch it to the pump and my ear and the sound would be much louder.

Now that just tells you the motor is running, doesn't necesarrily mean it's working!

Doherty Plumbing
12-13-2009, 03:26 PM
My system has many circulators and it was tough to tell when a pump was running. They make a slight humm. I was told to take a screwdriver and touch it to the pump and my ear and the sound would be much louder.

Now that just tells you the motor is running, doesn't necesarrily mean it's working!

You can usually tell the difference from a motor that's not working and one that is. Not to mention a circ pump that is not working will be VERY hot to the touch (IE hotter then the water in the system). Unless of course it's an older style oiled circulator. But seeing how it's new I doubt it.

It's possible the impeller is clogged up with sediment from within the piping system. You might be best to pull the pump once again and check the impeller if you think your pump is acting up. If the impeller looks fine then turn the pump on so you can make sure the impeller is spinning.