serious hlt hotspot issues

[Deebee]

There's a good little water heating calculator here -

http://www.jimsbeerkit.co.uk/calc.html

Cheers

MB

Yep i use that. Problem is after the alloted time yesterday the stc showed 55 degrees. The noise from the hlt was like it was about to boil. When i stirred the temp was over 80!

[Waffty]

From my experience, probe location can and will give you a variance depending where it is located, especially if it's a large vessel. If it's located near the element then it can get affected by it, likewise, a central located sensor could give a variance against a wall mounted sensor. In addition, if the probe is housed in a thermowell, then it's quite possible that the theromell could be affected by being directly in contact with the vessel surface. I had an issue with an Auber PID and Sensor combo, for the life of me, I couldn't get it work in situ but it worked perfect on the 'bench'. Spoke to Auber than they advised that this was common and that I need to use a nylon or similar washer between the vessel and the sensor/thermowell to provide a layer of insulation, as it was their view that the surface temparature of the vessel, was being conducted through the thermowell and into the probe itself, this wasn't against the full temp spectrum, which is why it was hard to diagnose. I did this and it worked a treat, by the same token, if I used a glass thermometer in the centre of the wort, whilst boiling and cooling, there is a slight variance between the wall mounted sensor.

Interestingly, the Braumeister uses a bottom located temp sensor, which is inside the malt tube and a good way away from the heating elements, this is a pumped system, so I guess the rational is that by heating the wort and pumping it from the bottom and forcing it up through the top of the malt tube, the temperature will be more even, so may you need a central sensor and some method of moving your liquid around? Would be interested to see/hear what the breweries do?

[Deebee]

Just orde4ed a cheap pump.
interestingly i turned the stc on again this morning. Water was at 30. Gave it a stir then let it be and when the stc showed 75 i gave it a stir. I ecpected there to be a change in temp but the variation was less than .5 og a degree.
i am thinking that warmer water is more stable??

[Andy]

Did you say where the stc probe is in relation to the element?

[Deebee]

When i used it first time the probe was about 4 inches above the element. Just about half way in the volume of water. This stayed the same yesterday.
Today ( after reading comments here) i lifted it slightly. That said i have no idea as to what the temp is like under the element but did whirpool it when i took a check.

I have ordered the pump, but aim to brew in the meantime so will leave it where it is. I will do another test at the weekend when the tank and water has cooled to ambient and check again. My suspicion is that warmer water will mix more easilly together than water which cold. I guess the tank would not show an even temperature til all the water is at the same temp and that can only be done by proper mixing .