Faulty heater element...need help please.

[pie man]

Hello,

I've been doing refrigeration for nearly a year now so I'm still learning and trying to get better in this trade! I was wondering does anyone have an idea how I can solve this problem.....

Went to a SURFRIGO milk chiller with both evaporator fans not working. There was alot of water which must have caused them to trip out. The evaporator coil was blocked with ice which caused the build up of water. Noticed this chiller had a heater element at the front, so I set the chiller to defrost but not working so I replaced it. Set to defrost and still the heater element wouldn't work. Also, there was a klixon located in the evap coil, shorted it out and the heater worked on defrost...so I ordered a new klixon. Wired it up and still not working! There's power to the defrost timer, I'm at a loss for what's causing this fault. I've spent alot of time on this job so would appricate if any engineer could help me!

Many thanks,

Paul

[Grizzly]

Hi Pieman.
Welcome to the forum!
It may sound a stupid question but.
When you powered up the heaters, was the coil still frozen?
Klixon's can be used as either a safety or a defrost termination device.
Meaning that they are closed circuit when below a certain temp.
IE. when cold enough due to the ice surrounding them or within the coil they sit in!
Once the coil temp has risen (Ice has melted) the Klixon becomes open circuit.
Hence no supply to the heaters through it.
When you have this sort of control.
Unless the Klixon is cold enough you will not supply the heaters!
Been caught out by this one myself.
But it is all logical if you think about it.
Cheers Grizzly

[pie man]

Hi Grizzly,

Thank you for your reply. The coil was free of ice so your probably right!!! I thought klixons would open circuit when the coil got too hot but if it wasn't cold enough to start off with, then I understand now the heater would not work. I guess I've ruled everthing out changing the parts so hopefully I won't get a call back to the job!!! Thanks again for replying.

Paul