Problem with boil

[Vellum]

So I just installed two 1700 watt elements in my brew kettle (on two separate 120v circuits). I just did a boil off test today and they didn't provide a very good rolling boil for six gallons of water. The water was only rolling boil directly over the elements. I also noticed that the boil was stronger directly over one element than the other. The kettle is a 15 gallon polarware that measures about 14 inches tall by 14.5 wide (diameter). I really thought 3400 watts would be enough to boil six gallons as others have had success with only 3000 watts. Any clues are appreciated or helpful hints. Cheers all!

 

[Onkel_Udo]

Have you insulated at all yet? Did you start the boil with the lid on? Was this a water test or wort? Water size and length were you extension cords?

Insulation (even one layer of reflectix type bubble wrap) will make an enormous difference.

Normally you should not need to start with the lid on but it can help initiate the rolling boil.

Wort boils more easily (rolling boil) that water.

Even if you extension cords are not getting hot, if they are undersized you will not me getting the most out of those elements.

 

[Vellum]

I have not insulated yet, I was thinkig that might be my next step but wanted to float for ideas before I proceeded. It was six gallons of water. I had the lid on until I hit boil, with the lid on a very good rolling boil occurs. The cords are each 9 feet long, allows me to hit multiple circuits in two corners o the kitchen. Cords did not get hot with the boil. This boil was strictly water as I was trying to determine my boil off amount for my water volume calculations.

 

[Vellum]

What do you mean by undersized cords are you saying awg rating or length or combo of both?

 

[Onkel_Udo]

What do you mean by undersized cords are you saying awg rating or length or combo of both?

AWG. In short (multiple pun intended) 14 gauge or better (smaller number) is what you are looking for. This is a continuous resistance load so cheating a size down does you no favors. 9' cords tend to 16 gauge or smaller unless you seek out the

It sounds like you probably got the technical build right just need to insulate and check you cords. If you are not going to direct fire the kettle, insulate the bottom as well.

 

[Vellum]

I picked out 14 awg cords from mcmaster Carr so it could handle the amperage. Looks like I'll insulate and see where that takes me. Thank you for your help

 

[kal]

Are your elements 120V or 240V? If they're 240V are you feeding them 240V? Feeding a 240V element only 120V cuts the power by a factor of four.

Another thing to consider is that a large volume of water like that generally speaking won't appear to be vigorously boiling, while the same volume of boiling wort will look more vigorous.

Kal

 

[Vellum]

They are 120 elements on 120 circuits. Interesting to hear that water has a different appearance than wort at boiling, I didn't realize wort boiled easier. Also a correction, my cords are 12 awg rather than the afore mentioned 14.

 

[kal]

There's generally less bubbling (or very little bubbling at all) in wort since there's no junk like hops to create nucleation points.

Kal

 

[MercMan]

Here's a youtube video I found of water boiling.
https://www.youtube.com/watch?v=sokd1rD-LPY

And for comparison here's a youtube video I found of wurt boiling.
https://www.youtube.com/watch?v=_6DCg2chxuM

 

[Vellum]

Well, I put a layer of reflextix on the pot, outside, as well as top and bottom. Seems to have a better looking water boil which I expect based on your opinions will provide a very good wort boil. The reflextix feels warm on the outside so I think I will place another layer on the pot. Obviously there is probably deminishing returns but I'll take what I cane get. Thank you for your help!