Pentair Mastertemp heater 400,000 BTU turned on by itself

[quincy915]

Last night my pool heater turned itself on. I've seen past posts on this happening. No storms prompted our issue. We had not used the heater recently. It's July in Texas!! Only turn on manually at the heater - no automation. I had just hit pool clean to add my chlorine when I heard the funny noise (the heater was on). This unit was installed 2015. But received a new replacement unit a year later. Pentair had to mess with the unit because of all its issues. I think the touchpad was the final diagnosis! Geez. And, presently, the cover over the touchpad is in place and not cracked. And, we really haven't used the heater that much (pressing of pad alot ). Soooo, I'm out of warranty. Should I assume it's the touchpad and order/replace myself? Shouldn't the heater give error codes? Any help would be appreciated. Sounds like Pentair knows about their touchpad issues. But a heater firing up by itself I think could be dangerous.

 

[JoyfulNoise]

Is the heater receiving power all the time? Usually in a stand-alone heater, one installs a "Fireman's Switch" so that the heater is never powered unless certain conditions are met. With simple mechanical Intermatic timers, a Fireman's Switch would look like a small contact switch that is activated when the pool pump is ON. In other setups, a Fireman's Switch would look like a physical key-switch that the pool owner has to go and manually turn on in order to power the heater's electronics. The purpose of all of these different types of configurations is to make it so that the heater can never just turn on by itself, ie, some other condition has to be met before power is applied.

With automation systems (like the EasyTouch system), there are internal relays that control when the heater receives power. So in my pool, the heater can only turn on if the automation panel is in POOL or SPA mode and if the set temperature is higher than the water temp. If the system suddenly switches to some other program that doesn't include the POOL mode feature (say a "GENERIC" feature circuit where all I'm doing is running the pump at low speed to get some simple skimming action), then there is no power applied to the heater and it physically can't run.

So, with all that said, how is your heater receiving electrical power?

 

[quincy915]

Is the heater receiving power all the time? Usually in a stand-alone heater, one installs a "Fireman's Switch" so that the heater is never powered unless certain conditions are met. With simple mechanical Intermatic timers, a Fireman's Switch would look like a small contact switch that is activated when the pool pump is ON. In other setups, a Fireman's Switch would look like a physical key-switch that the pool owner has to go and manually turn on in order to power the heater's electronics. The purpose of all of these different types of configurations is to make it so that the heater can never just turn on by itself, ie, some other condition has to be met before power is applied.

With automation systems (like the EasyTouch system), there are internal relays that control when the heater receives power. So in my pool, the heater can only turn on if the automation panel is in POOL or SPA mode and if the set temperature is higher than the water temp. If the system suddenly switches to some other program that doesn't include the POOL mode feature (say a "GENERIC" feature circuit where all I'm doing is running the pump at low speed to get some simple skimming action), then there is no power applied to the heater and it physically can't run.

So, with all that said, how is your heater receiving electrical power?

Matt

I don't recall a Fireman's switch. I will look when I get home. We don't use the Easy Touch communication cable. We did have a Pentair professional install both the pump and heater. Would that be standard in an installation?

 

[ajw22]

The "firemans switch" is simply a low voltage cable that the ET relay turns on or off to control the heater. If you are handy you can find that wire connection between the ET panel and the heater. You can check with a multimeter if the relay is stuck closed. A critter could have chewed on the cable and shorted it. The firemans switch is the first place I would check.

ET manual is here --> https://www.pentair.com/content/dam...em_Load_Center_Installation_Guide_English.pdf

Heater connection explained on page 17. J19 is the connection in the Load Center.

 

[JoyfulNoise]

Please post a picture of your equipment pad showing the heater and how it is wired. I’m confused about your setup. It sounds like you simply have a stand alone heater that is powered all the time and no automation system at all.