Delta T In Lochinvar Energyrite

GoPre

In The Industry
May 14, 2022
8
Ohio
Hello. I have a few new Lochinvar Energyrite pool heaters. Recommended Delta T is 10-14 degrees. I am having an issue with higher Delta T on one and can’t get it down, 20 degrees is as low as I can get it. It looks like I need a new bypass valve.

I understand the issues with a low Delta, but what is the problem with a higher Delta? I understand you don’t want to damage equipment and piping, but I wouldn’t think a 20 degree Delta would hurt anything.

Thanks!
 
If the flow rate is unknown, ensuring the temperature rise across the pool heater is between 10°F and 14°F will ensure the proper flow rate (reference the Service Menu Descriptions - Delta T section of the EnergyRite Service Manual).

Adjustment of auxiliary bypass

1. Backwash and clean pool filters.

2. Start with the bypass valve in the half open position.

3. Start the pool heater.

4. Check the temperature rise across the pool heater

(reference the Menu Descriptions - Delta T section of the EnergyRite Service Manual).

5. If the temperature rise across the pool heater is more than 14°F, close the bypass valve to increase flow to the pool heater.

If the temperature rise across the pool heater is less than 10°F, open the valve to decrease flow to the pool heater.

6. High water flow can cause condensate and operational problems which are non-warrantable.

 
A 20 degree rise indicates insufficient water flow and this needs to be corrected or you can damage the heater.

What exact model do you have?


1670086751904.png
This shows the expected temp rise (inlet to outlet) (Y-axis) vs. Flow in GPM (X-axis) for a 400,000 btu/hr heater at 84% efficiency.

The minimum required flow is 40 gpm.

So, the maximum temp rise should be 16.8 degrees Fahrenheit.

Every heater has a minimum required flow rate.

So, you should never go below the minimum required flow rate.
 
They specify 14 degrees as the maximum delta T, which is about 48 GPM for a 400,000 btu/hr heater at 84% efficiency.

The efficiency of the heater should be on the label, what does that say?

1670088744641.png
 
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