Can you make a gas heater more efficient?

[Camaro4life18]

I bought my home a year and a half ago, so I've got 1 summer under my belt of managing my pool. I bought the house with a home warranty, where I put in a claim to get the pool heater fixed.
Raypak 2100 ...installed back in the 90s I think.

First off, let me say the warranty is a bunch of BS. Repair guy came out, spent $1,100 and got it running. Warranty company says the repair is not covered under normal wear and tear. I'll let you know what happens in small claims court on that one.

Anywho, all last summer I noticed an incredible amount of heat that escapes out of the top of the heater. The heater works, I'm monitoring temperatures coming into and out of it, and I get 4-5 degrees warmer with a single speed pump. So my question is has anyone done anything to make better use of all the heat coming out? I've looked at installing a 2nd tube system and basically running the water through twice, but its like another $1,000 to get all the parts required.

 

[proavia]

Use a solar cover on the pool to help retain the heat.

You realistically can't make an old heater more efficient.

 

[Bperry]

Same experience with the warranty here. Won’t spend any more on that again, it’s a pretty common scam (I mean complaint)

 

[1poolman1]

I bought my home a year and a half ago, so I've got 1 summer under my belt of managing my pool. I bought the house with a home warranty, where I put in a claim to get the pool heater fixed.
Raypak 2100 ...installed back in the 90s I think.

First off, let me say the warranty is a bunch of BS. Repair guy came out, spent $1,100 and got it running. Warranty company says the repair is not covered under normal wear and tear. I'll let you know what happens in small claims court on that one.

Anywho, all last summer I noticed an incredible amount of heat that escapes out of the top of the heater. The heater works, I'm monitoring temperatures coming into and out of it, and I get 4-5 degrees warmer with a single speed pump. So my question is has anyone done anything to make better use of all the heat coming out? I've looked at installing a 2nd tube system and basically running the water through twice, but its like another $1,000 to get all the parts required.

You could try to put a second heat exchanger of some sort above the heater exhaust but would end up with the same issues that heaters that are made that way have, ones like the Pentair ETi and Jandy Hi-E2. They are called "condensing heaters" because of all the condensation the second exchanger produces as the water makes that second pass through the residual heat. The pH of the condensate is usually between 3.1 and 4.2, very acidic. You would have to find a way of disposing or neutralizing that condensate as it will damage everything in contacts, including concrete.

Your heater is in the 82% efficiency range when new. Condensing heaters are about 95% efficient. Right now, your heater new would cost about $3600 if it is a 400K. A Pentair or Jandy as listed above is usually more than twice that amount.

While it seems to be a lot of heat out the top, the actual temperature inside the heater firebox when running is about 2000 degrees, per RayPak's engineers.

That being said, I know an HVAC contractor that did it with spare parts he had in his shop. He claimed it made a difference, but everything he did was in my way as I tried to diagnose/repair his heater that he could have done himself.

 

[JoyfulNoise]

Dropped the home warranty after two years with it. Makes little financial sense and their limitations and restrictions basically make them unusable for all but the most trivial repairs.

Short answer to the question in your title - buy a new heater …