Help sizing circulator pump
#1
09-07-08, 04:26 PM
Help sizing circulator pump
I have a hot water heating system with a Thrush circulating pump (1/8 HP motor, marked Model H Part CH4 on the bracket). Last winter a seal appeared to go bad as it began leaking out the weep hole and started getting water in the oil. I can't find anything that would help me find what size pump I should use as a replacement. Any ideas?
#2
09-07-08, 05:54 PM
Three options leap to mind:
1) call Thrush and ask what the replacement would be. Also ask for a competitor cross-reference (e.g., Taco, Grundfos).
2) figure up a resistance curve for your longest zone and size the pump to that. Good instructions here:
http://www.taco-hvac.com/uploads/Fil...irculators.pdf
3) take the specs (or the pump) to your local plumbing supply house. Find the senior member of the shop. Ask him what would replace it.
The good news is that a new circulator like a Taco or Grundfos will probably use a mere fraction of the electricity that the Thrush does.
1) call Thrush and ask what the replacement would be. Also ask for a competitor cross-reference (e.g., Taco, Grundfos).
2) figure up a resistance curve for your longest zone and size the pump to that. Good instructions here:
http://www.taco-hvac.com/uploads/Fil...irculators.pdf
3) take the specs (or the pump) to your local plumbing supply house. Find the senior member of the shop. Ask him what would replace it.
The good news is that a new circulator like a Taco or Grundfos will probably use a mere fraction of the electricity that the Thrush does.
#3
09-13-08, 03:30 PM
I got the current Thrush replacment info, the pump curve matches a Taco 010 3-speed on medium, so I guess I'll go that route. I currently have steel (black) pipe as the water lines. Should I be using any additive when I refill the boiler (I've read about products available to prevent corrosion in the pipes).
