UTH question

[yz9890]

placing the thermostat probe between the UTH an the bottom of my 20gal long creates a noticeable gap between the heating elements and the glass. with the thermostat set to 100deg, I only get 87 off the floor above. Is that an average heat loss? is there a better way to mount the probe and UTH to get rid of the gap?

thanks-

[The Serpent Merchant]

You can attach the probe to the bottom of the UTH, that should eliminate the gap.

[yz9890]

I wondered about that. Thanks.

[Vypyrz]

is there a better way to mount the probe and UTH to get rid of the gap?

thanks-

You can also make a base to mount the probe and heater to, and then set the enclosure on top of it. You can make them out of wood, melamine, or polystyrene insulation.
Here is how I did it with melamine:

Routing a channel into the wood that is just deep enough so that the probe is slightly taller than the channel:





Mounting the probe into the channel:



Mount the UTH over the probe:



And here are a couple of photos of how I do it using polystyrene insulation. You can use a screwdriver or something to press an indention into it for the probe to lay in, tape the UTH over that, then set the enclosure on it.



Here, you can see part of the UTH base sticking out from under the tub:



I used this set-up to keep my tubs temporarily heated in a hotel room during our hurricane evacuation last year. 1 Johnson thermostat, 3 UTH's, 6 tubs...

[kitedemon]

If you have a room temp that is cool and variable you may consider mounting the probe to the glass over the place where the uth is. This will provide more stability in temps. You will need to very firmly fix it. I use hot melt glue place the probe down dry and run glue along the sides and over the top I also run along the cord back most of the way inside the enclosure. Make sure it cannot be moved you should be able to push and pull at it and not move it. Then run your substrate over it set the t-stat to a max of 94 and you are done. Don't place too much substrate over the hot side it is a great insulator.

If you choose to go this route I would also recommend a failsafe. Actually I'd recommend a fail safe in all cases, the only time I would not is if you have a new herpstat and enable the mechanical relay over and under alarm settings. Even that being said I one one that has these functions active and still use a failsafe.

There is a lot of discussion over this by the enclosures I have that I chose this had wild shifts before I went this way due to big room temp changes. I was seeing hot spots that shifted from 86º to 101º the t-stat was set to 100º the room temp varied too much and the probe insulated from the air temp failed to adjust correctly.

[Trackstrong83]

You can attach the probe to the bottom of the UTH, that should eliminate the gap.

x2
I noticed the huge gap as well, so I taped the probe to the bottom of the UTH. Which works like a charm

[yz9890]

x2
I noticed the huge gap as well, so I taped the probe to the bottom of the UTH. Which works like a charm

I switched mine out last night as well and it's working much better.