Hi KdBlev,
You could go with the same replacement motor which is the
Century UST1102 1 HP Up Rate Motor there is also the Energy Efficient Version of this Motor which is the
UCT1102 1 HP Energy Efficient Motor, the UCT1102 will give you the same output of water as the UST1102 but costs about 20% less in operational costs.
You could go up to full rated 1 HP ST1102 motor which is the exact same motor as the 1.5 HP UST1152 UpRated motor as they both have the same True HP. I will run the number below to make sense of this.
1 HP ST1102 Full Rate Motor - 1 HP x 1.5 Service Factor = True HP of 1.5 HP
1.5 HP UST1152 Up Rate Motor - 1.5 HP x 1.0 Service Factor = True HP of 1.5 HP
For whatever reason the
1.5 HP UST1152 Up Rate Motor is less expensive than the 1 HP Full Rate so I would go with the
1.5 HP Up Rate UST1152. If you do decided to go up in HP then you will need to replace your impeller as if you use your old impeller you will only be getting the output of water from the 1 HP impeller but you will be paying for the cost to run the 1.5 HP Motor.
Also when upgrading to a larger HP you will need to make sure your filter can handle the increased output of water from the larger motor. For example if the new motor now means your pump is outputting 100 GPM and your filter can only handle 75 GPM then this is no good as you will get shorter life out of both your motor and filter.
If you decided you wanted to go Ultra Energy Efficient then I would not suggest Dual Speed and would suggest this
1.65 HP Variable Speed Motor Replacement as the price is not much more than the dual speed but this variable is much easier to install, gives you much more flexbility since it can operated at a full range of RPM's from 600 - 3450, will save you a ton on operational costs (up to 80% operational cost savings) and you may be eligible for power company rebates.
Could you send us photos or model information for both your filter and your pump as this would allow us to suggest the proper impeller and let you know if you can go up to 1.5 HP. We would also suggest a shaft seal but will need to know your pump model information.