Old bev air bm23 temp variation between kegs in same kegerator

I have a super old bev air bm23 that I've had in use since early January. Thus far I've had 4 different commercial sankes on tap with relative success (i.e. System was balanced with steady 39f liquid temps, minimal first beer foam etc). Each time I contacted the brewery for volumes of co2 the beer was packaged at and for the last two beers, a troegs and great lakes keg, my pours were spot on from the beginning. When I had issues with one particular keg, a genny bock keg in the past, i followed ice ace"s advice to pour, observe the bev line for co2 breaking out of solution, turn the regulator an 1/8 turn, wait ten mins repeat as necessary, with great success.

This past Friday I kegged my first homebrew batch, which was transferred in a standard ball lock corny keg. Friday night I began force carbonating at 30psi for 24 hrs, then reduced to 12 psi to eventually hopefully target 2.5 vols of co2 at 39f.

On Saturday I purchased a 1/6 barrel genny Pilsner keg. At this time, due to the holiday, no one was available at the brewery to tell me what vols the co2 was packaged at. Since the genny bock keg was kegged at 2.65 vols, I figured it was probably a safe bet that the pils was as well. Using the carb chart, I set my regulator for that gas line to 14psi, assuming my liquid temp was my usual 39f.

Since Saturday I've had massive foaming on every pour of this genny sanke keg. I've tried using ice ace stanrdard advice for troubleshooting to no avail. Since the liquid temp for the genny keg was running high at 41-42f, I turned the thermostat down a day later and temps are still on that range. I'm up to 17psi and the temp for the genny keg is still running high and pouring virtually all foam, when technically it should be in the 2.7 vol range. I also observe co2 bubbles in the bev line comming out of solution still. It should be noted it has been pretty humid and hot here since Friday. My tower was sweating badly and for the first time I installed a sanke to ball lock conversion kit onto my sanke coupler so that I can seamlessly transfer from commercial keg to homebrew keg and dispense from the same line
http://www.cornykeg.com/resources/corny-keg-tips/converting-sanke-ball-lock-keg/

On the other hand, my corny keg, which is positioned to the left of the sanke keg and slightly further back towards the rear of the box, gave me a liquid temp of 35f last night after I turned down the thermostat attempting to fix the commercial keg. The homebrew is carbing nicely after 3 days but in fear that my homebrew might freeze or be over carbonated at such a low temp, I turned the thermostat back to the original setting which usually provides me with 39f beer.

Any thoughts as to what the heck is going on? Can the left side of my kegerator really be that much colder? Are the thinner walls on the ball lock absorbing more cold air than the standard 1/6 barrel? Just an FYI I checked my thermoworks digital thermometer twice today in ice water and it read 32f, I have 6ft of 3/16" bev line, and I just cleaned the lines again .......please help me try to diagnose this! Thanks!

 

Thanks Doug. Yes my steady state temp was with one keg only. My door seal certainly isn't perfect. I replaced it brand new but the old door is a bit crooked and I added hinge straps to pull the door tight. This is the first time I've had two kegs in at once and tried pouring from both. I've had two kegs in the box in the past but the one tapped wasn't moved and I didn't notice any foaming or temp variations. I'm guessing it is likely a circulation and seal issue (combined with the fact that the commercial keg on the right side of the keg is slighly closer to the door).

What can I do to improve circulation, short of calling a pro ? Thanks again!

 

Fwiw, which may not be much, I moved the kegs to they are even and equidistant from the door. I'll let them set for several hours and pour, dump, pour each into a room temp glass to compare temps. If they are still quite different maybe I'll swap kegs and let them sit for several hours to see if temps swap for each keg.

 

That's what I figured u may suggest. I assume you plug the cell charger externally and where would you place the computer fan ideally?

I wonder how much a new replacement fan would be, with installation (I'm not very handy, changing the door seal and putting in the air hose were a process haha).This unit is ancient and I traded about $50 in beer for it (included delivery ha). It works great with one keg this is the only time I've experienced temp variation of any sort.

 

Hi Doug there is definitely cold air returning and a slight vacuum effect down into the box. The tower is cold and not sweating today due to lower heat and humidity. I also added reflectix to the outside of the tower a
A few days back to further cool the tower.

As for wiring....I can maybe seek help

 

Exactly I'll check over the next day or so and go from there

 

Well just checked....homebrew keg on the left reads 37.8f, commercial sanke on the right 43f and foam at 16psi...the odd part is my kegs in the past have always been placed on the right side the commercial keg is currently located (with overflow bottles on the left side) and I consistently had 39f beer on the setting it's currently at. I'm perplexed. The only new variable is the sanke to ball lock converter on my sanke coupler.

I bumped the psi for the sanke up to 18 and will let it run overnight. Due to the fast flow rate and my 6fr line length I doubt this will work. Next, I'll swap positions of my homebrew keg and sanke and see what happens temp wise. At least with my homebrew which is still in the process of.carbonating, I have more control over my final carb volume...ugh