Choice of new gas heater?

[sjsoldo]

Have a Minimax 250 that I have kept going for 20 years with repairs along the way. I have fixed this thing so many times it is like an old friend. But the heat exchanger is leaking and I think it is done.
Shopping for a new gas heater for 25,000 gal pool. I was thinking Mastertemp due to my familiarity with the Pentair parts and instructions.

But maybe I am misguided. I use my heater 4 months a year. What product do you recommend???

 

[ajw22]

Consider a Raypak heater. It is a natural draft heater without the complexity of a forced draft fan.

Pentair MasterTemp is a good heater. It has a smaller form factor than the Raypak due to the use of a blower creating a forced draft. However the forced draft has more complex parts and is more costly to repair when there is a problem with the fan or associated components.

 

[sjsoldo]

In your experience is the Raypak more reliable? Is it easy to repair? Are parts available?

 

[ajw22]

In your experience is the Raypak more reliable?

They all have their quirks.

Is it easy to repair?

It is simpler to repair with less expensive parts.

Are parts available?

Yes.

 

[Panzer]

I've had a Pentair MiniMax 100, a Rheem (Raypak) 106A, and now a Hayward 135 (seen in my signature).... obviously these were smaller units than yours.

The Pentair was with the pool when we bought the house and other than replacing the Thermopile (millivolt system) every other year, it was very reliable. (guessing around 12 yrs old when we replaced it).
The Rheem (Raypak) we bought new and had nothing but, issues with it. Relays blown, terrible sooting issue despite having it repeatedly looked at by HVAC guy, gas valve replacement, & burner tray failure. (~4 yrs old) Last year I waited 3 months for a new gas valve (COVID delays) only for it to run twice before the burner tray failed.
In talking with the HVAC tech, he mentioned that having a forced draft unit can help alleviate certain issues. I opted for the Hayward as several friends/family have them (forced draft models) and they are all well over 8 yrs old. I'm in the first season with the Hayward so, time will tell.

If it's important to you... the natural draft heaters were notably quieter than the forced draft unit. (no fan noise)

Best of luck in your search.
Respectfully,