Loud explosion when Pentair heater starts, then runs fine.

[o_O]

We’ve got a Pentair master temp that was installed by the previous homeowners in 2017.

When it starts up there is a very loud explosion that sounds like a metal trash can being hit with a bat, and then the heater continues to run just fine.

Is it worth trying to fix this or should we just buy a new one? I emailed and called a local pool supply place about taking a look but they haven’t returned our calls. I also don’t want to spend $1500 repairing something that costs $2000 new.

I’ve shut the heater off as 1) it’s summer and the pool cover heats it just fine 2) I don’t want it to blow up the house. Any suggestions are welcome.

 

[ajw22]

The heater NG or propane?

What size MasterTemp heater is it?

The heater costs more like $4,000+ new.

It may be worth a service call to have a certified gas tech examine the heater.

First thing I woudl check is the igniter.

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

 

[o_O]

It’s natural gas Pentair master temp 400 high performance heater. I’ve noticed that the cement slab it’s on is now looking like a rust colored liquid is leaking out from under the heater itself. That stain wasn’t there on the cement slab earlier.

 

[o_O]

 

[ajw22]

The explosion likely cracked the burner can and maybe heat exchanger.

There are YouTube videos on how to disassemble the heater to get a look at what happened.

My guess is a new heater is in your future.