Secondary pump on circulating line.

[WingWingSr]

I manage a 120 unit, 3 floor assisted living facility. I recently replaced the recirculating pump and also found some crossfeed of hot and cold water which I fixed. My problem is the kitchen sinks, 3rd-floor last few rooms do not hold the temperature for more than a couple of minutes. I am considering adding a booster pump, or a secondary pump on the recirculating line to help push the hot water to the end rooms. My question is, can you have more than one pump on a recirc. line?

 

[GReynolds929]

The pump is only there so that the hot water is there pert near instantly. If temp is not staying constant it is not an issue with the pump, there is something else causing it. That being said if the pump is not rated for the head pressure required to push water three stories vertically than a different pump is needed.

 

[HWSleuth]

Is there maybe a cross over in those problem rooms? As Mr. Reynolds advises a larger pump is better than complicating the issue by multiple pumps. To perhaps get more insight as to what is happening try this:
1. Remove existing pump and connect a large ID garden hose on the return line and let it run.
2. Can you run water long enough to get hotter return water back to the water heater?
3. If so, does this correct the hot water concern in the rooms?
4. If neither improves, I’d look for a crossover in those rooms or an adjacent room.
5. If returning water quicker with the hose improves the problem rooms, look at a larger pump.

 

[WingWingSr]

The pump is only there so that the hot water is there pert near instantly. If temp is not staying constant it is not an issue with the pump, there is something else causing it. That being said if the pump is not rated for the head pressure required to push water three stories vertically than a different pump is needed.

Thank you. I replaced the pump with the exact same one that has been doing the job for 4 years.

 

[WingWingSr]

Is there maybe a cross over in those problem rooms? As Mr. Reynolds advises a larger pump is better than complicating the issue by multiple pumps. To perhaps get more insight as to what is happening try this:
1. Remove existing pump and connect a large ID garden hose on the return line and let it run.
2. Can you run water long enough to get hotter return water back to the water heater?
3. If so, does this correct the hot water concern in the rooms?
4. If neither improves, I’d look for a crossover in those rooms or an adjacent room.
5. If returning water quicker with the hose improves the problem rooms, look at a larger pump.

Thank you. Will try this tomorrow. fingers crossed.

 

[Twowaxhack]

The system may have multiple return loops with balancing valves. You could have a bad balancing valve.