isotherm marine fridge temperature issues (1 Viewer)

[ifsmithy]

Wondering if anyone here may have an idea......while I wait for tech support to never likley get back to me......

I have an isotherm classic 36l marine fridge exactly like this one in the back of my 80 series.

The fridge has been cooling the contents too much such that it freezes water and some foods.
I have replaced the thermostat and it is still freezing water.

The compressor does switch off when i rotate the control knob to its lowest setting but water still freezes.

I suspect the thermostat sensor is not in the correct location - however i am unsure how to position the sensor -there is a hole in the back of the fridge into which to insert the sensor but there is no way to see where it ends up within he fridge - there is no apparent opening in the inside of the fridge to see where the sensor is - seems like a silly design?

My next idea to make sure it is the sensor location that is the issue is to unthread the sensor and locate it directly within the fridge - I should then be able to control fridge temp if that is working correctly...

Thanks in advance!

Ian

 

[e9999]

Well, the good thing is that your compressor and motor are good. So, worst case scenario, you have a good freezer.

Do you know what kind of sensor it is? (RTD, thermocouple....?)
It's not very likely that the sensor did shift position significantly, but possible. There is a chance (more likely than the former, I think, but still not very likely in the absolute) that the sensor is faulty. If it's easy to remove it from the fridge, I would. You can then test it by putting in ice cold water and see if the compressor stops at the correct setting, etc. Could also be the temperature control knob rheostat.
Of course, it could even be a control board issue. That could be expensive / difficult to fix.

 

[ifsmithy]

Thanks for the reply!!
This is the t-stat - sea00031da

Replacement Thermostat for Cruise Classic Refrigerators | Isotherm SEA00031DA

Isotherm replacement thermostat for "Classic" Cruise refrigerators. This thermostat will not work with "Elegance" Cruise Models. See below for additional application information.

rvpartssource.com

its just failed a continuity test - I placed the sensor end in ice water and left it for 30 mins and there is always continuity at all t-stat settings when I rotate the dial..... so as I understand to the t-stat will always be telling the fridge to cool......slightly annoying as this is the second t-stat ....... at 55 bucks I'll just order up another t-stat....and make sure to test continuity in ice water before I install this time!

thanks again

 

[e9999]

Don't know much about these things but looks like some sort of pressure-based sensing system. If so, you'd want to make sure the tubing is not crimped someplace.

 

[ifsmithy]

thanks - will post up if I solve it - waiting on new t-stat and will check crimping - nothing obvious!