Teledyne heater series 1 - Luke warm water at best

[mishforsmiles]

I just recently purchased a teledyne series one pool heater for a 22 foot above ground pool. There is heat coming from the top of the heater and all burners are lit but the water return from the heater into the pool is Luke warm at best. When I restrict the flow of water from the heater back to the pool with the valve on the pool the water temp goes up slightly but not much but also this flow restriction sends my filter pressure through the roof. Any advice or direction that anybody could offer would be greatly appreciated. Thank you. I attached a photo of my setup.

 

[ajw22]

Welcome to TFP.

How many BTU's are the heater?

What is the CFM of your house gas meter?

Show us pics of the gas connection of the heater?

What is your exhaust temperature?

The heater was used. A scaled heat exchanger can be causing heat to go up the exhaust instead of into the water. Or limited gas flow can reduce heat output.

Slowing the flow will cause a greater outlet temperature. Read Heater Maintenance - Further Reading

What you call lukewarm may be the normal temperature rise of 10 - 12 degrees.