I have a Central Boiler 5036 Outdoor Wood Furnace.
My Taco Model 009-F5 Circulation Pump just died.
The plastic impeller had disintegrated and was mostly missing.
I replaced the cartridge with Cartridge # 009-021RP.
It is working but apparently the flow is obstructed.
I have a water to water heat exchanger.
My guess is that the heat exchanger is plugged up with pieces of plastic from the impeller.