Pentair ETI Hybrid: First Winter Season

[Carpe]

Hi All,
I'm now into my first winter temperatures in the first season of my new pool.

I had the builder install the Pentair ETI Hybrid Heater for energy efficiency here in Denver, Colorado, but in our first day below freezing and I'm getting a message of 'Condensate Block'. I've had the heater operating in gas only mode (I understand that the heat pump should not be operated below 50 deg ambient temp) for the past few weeks. From what I can tell the condensate line off the gas heater exhaust is frozen. I'm intending to keep the pool/spa open through the winter.

Looking through the manual, it appears that this heater cannot be operated in the winter freezing temperatures, even in gas-only mode. The reference I see to this is buried in the installation/user guide toward the back, a fact that Pentair does not indicate on their website, fact sheet, and the builder didn't mention (or probably know about) at all. Of course, if this is true, I'm seriously irritated at the builder for failing to note this (and steer me away from that heater) and for Pentair to not make that more apparent.

My question is - does anyone have experience or know how this heater can operate in freezing temperatures?

UltraTemp ETi® Hybrid Heater

The Pentair UltraTemp ETi® Hybrid Pool Heater is the first swimming pool heater to combine a heat pump and a gas fired heater for an energy saving alternative.

www.pentair.com

 

[ajw22]

Gas heaters should not be operated with cold water because it creates corrosive condensation in the exhaust. Read...

Heater Condensation - Further Reading

www.troublefreepool.com

You need to keep your gas heater running so water temp is always above 70F to prevent corrosive condensation.

 

[Carpe]

But the condensation comes out all the time whenever the heater is running, and if that freezes doesn't that mean the heater won't function? The water was about 68 this morning but now has dropped to 60 today without the heater, even though it was called to heat. Pump has been running continuously.

 

[ajw22]

See page 5 of your manual --> https://www.pentair.com/content/dam...ultratemp-eti/ultratemp-eti-heater-manual.pdf

Your fancy heater has a Flue Gas Condensation Management system that other gas heaters do not have to neutralize the corrosive condensation.

Page 33 discusses the condensation drain from the Heat Pump section.

Page 40 says Condensate drainage frozen due to operation in freezing temperatures - Shut down and properly winterize heater.

I would call Pentair and discuss with them under what conditions your heater is designed to operate.

 

[Carpe]

Thanks ajw.

A heads up to anyone else considering the Pentair ETi Hybrid heater: after speaking with Pentair, I'm finding this heater is not meant to be installed in any climate where freezing temperatures may occur, even if running the heater in gas-only mode.

This heater always produces condensate whenever the gas heater is running (regardless of water temperature) so there also will always be water in the condensate drain line; due to the length and routing of that line with the condensation management system it will freeze.

I will continue to have the pump run 24/7 until we're out of this cold snap and just winterize for the season.

 

[ajw22]

A heads up to anyone else considering the Pentair ETi Hybrid heater: after speaking with Pentair, I'm finding this heater is not meant to be installed in any climate where freezing temperatures may occur, even if running the heater in gas-only mode.

Unfortunately that is what I suspected but wanted you to find out from Pentair directly.

 

[swamprat69]

If the only problem is the condensate line freezing, many commercial walk in freezers have condensate lines inside the freezer and the use of a heat tape and insulation prevent the condensate line from freezing and backing up.