Can You Suggest a Bigger Circulator?

Hi.

I have hot water radiators in my house. The boiler has a green Taco F007 circulator on it. There are two radiators in my house that hardly get any hot water. This summer I would like to add a radiator in my attic. I will need a bigger circulator. Can you recommend one? Thanks!

Leo

Do you have seperate zones? Is it a monoflow system?

I have 1 zone, and its not mono flow. There's two 2 inch main running around the basement, one hot water, one cold water. And then Ts shooting out for each radiator. I'm not sure what the name is for this design?

Do you really need a bigger circulator?

Or just new valves on the radiators that are overworking?

With working valves you can choke the flow to those hot radiators and have left over flow to go to the cold ones -- That's a balanced distribution of energy. If you force more liquid into the radiators that are already hot -- one or two things could happen - one the hot ones might just get hotter without the cold ones improving - two the whole system will not work as the water will flow too fast, and energy will not be given off in the radiation - OR it will not be collected from the available produced energy of the boiler -- the exchange will be defeated!

Are they cast iron rads? Are they on the second floor?
If so check out this article. http://www.oldhousejournal.com/how_to_take_care_o ... azine/1563
Sometimes they would put a metal orifice in the valve to slow the flow to that radiator.

Everything is cast iron. I have 4 radiators on the 2nd floor. And it was always hot up there. I replaced 3 valves. I turned the one off and reduced the other 2 so the rooms are cooler. I saw a marginal improvement in the one radiator downstairs and no improvement in the other one. Maybe I should replace all the other valves in the house to choke off excess heat. I want to move the radiator that I turned off to the attic.

I'm just concerned that the circulator will not have enough balls to send the water up 2 flights and over another 15'. Is there somekind of pump I can install on the 2nd floor to help the water reach the attic if necessary?

In a closed hydronic system the circulator only has to overcome the fluid friction resistance of the piping. There is no height "head" to overcome. When the circulator pumps every molecule of water starts to move a the same time. Whatever gets pushed an equal amount is pulled. Make sure your system pressure is high enough. For a system with a max height of 20 feet above the diaphram tank and a 5 psi margin the expansion tank initial fill pressure should be 13.7 psi. The make up water regulator should also be set at 13.7 psi.

What kind and size piping do you have?

There's a 2" or 2.5" main running around the basement, and then 3/4" pipe going to each radiator. From your explanation, it appears that the best thing I could do is replace all the fozen radiator valves. Then choke off any extra heat in each room.

I don't think my system is using an expansion tank. I see it down there, but I don't think its being used? The boiler psi is around 17 ro 18. If I increase the PSI, would more water get pushed to the radiators that are furthest away from the boiler? Thank you!!!

Given that you have large pipe sizes you may have an non-diaphragm style of expansion tank. Could you post a photo of what you have, both the tank and the water supply regulator. I assume you are measuring the system pressure at the boiler level, perhaps using the pressure gauge on the boiler. Increasing the pressure will not help. The circulator just increases the pressure on the output side while reducing it on the inlet side. This is what causes water circulation, a differential pressure. You likely have a blockage, bad valve, rust, etc. or an air pocket blocking water flow to the radiators that don't heat. Have you tried to bleed air out of the radiators that don't heat until water flows out of the bleed valve? Do so and report the results. We will be able to pin point the problem, have faith.