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Flex Heater

12 Reviews

Need to heat your Flex during the long Winter months? Want to make a Belgian ale with notes of pears, bananas, bubblegum, anise or even rose petals? No fear, we have the solution! Each Flex has its own sized heater and the wattage of each is carefully designed to match it. We also use a built-in thermostat, which stops the heater from getting too warm.

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Estimated Total $70.00
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Some of us will have to heat our Flex during the long winter months. No fear, we have the solution! The Flex heater was carefully engineered to match the heating needs to maintain set temperatures even in the coldest winter garage. We also use a built-in thermostat which stops the heater from getting too warm. This means you get a gentle warming action when your beer drops below your desired temperature opposed to rapid heating which can overshoot or 'cook' your wort.

Our heater attaches to the insulated FLEX jacket via Velcro. It is positioned near the bottom cone section of the fermenter where the coldest liquid is. This will give the most even temperature throughout your fermenter (happy yeast!).

Technical Features 

  • Built in 95F thermostat to prevent the heater from overheating your wort 

  • 80 watts of power 

  • Durable silicone construction 

  • 5' long cord


Note: Our heaters were designed to keep the wort within normal fermentation temperatures. Yeast strains (like Kveik) that require higher temperatures (90F+) may require an additional heat source.

Pro Tip: If you’re looking to ferment with Kveik yeast, we recommend taping the heater to the cone as it'll help aid in heat transfer and provide for high fermentation temps.

Have more questions?

Head over to our FAQ page for quick answers!


Customer Reviews
4.7 Based on 12 Reviews
5 ★
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United States United States

Works but NOT Durable

While working they do the job fine but I’’ve had two of these fail. They short out in the same location on the neutral leg. I’ve seen comments on the Facebook group to just contact Spike and they’ll send you another - one guy said he was on his 6th replacement. Sounds like that season’s over though as they just notified me I was out of the one year warranty period so be warned.

Seamus C.
United States United States

Kick ***

Absolutely love it and behind my neoprene jacket with ambient temps in the high 20's, 9 gallons sat at 67°. Love it!

Patrick C.
United States United States

Heat pad

Great heat pad, did have issue with wire connection which Spike made right. Excellent support, continuing my use and expansion of my Spike brewing environment.

Canada Canada

Virtual high-five for incredible customer service

This flex heater has been instrumental in allowing me to ferment multiple batches at one (as my fermentation fridge only accommodates a single Flex+ fermenter). However, it recently stopped working with a suspected thermostat error. Spike CS sent me a new one, and it's working like a champ. The reason I post this review is really to endorse the customer service team. In Canada, I am a secondary customer in that I must order through an authorized dealer. In spite of this, the Spike team sent me a replacement without the hassle of me going to my original supplier. Many applause guys.

Darin B.
United States United States

Flex Heater

good coverage, stays in place, works good.

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