I am working on a K machine, that runs at 36.0 +/- 0.2 temp, regardless off what the set temp is. When calibrating HEAT TEMP CONTROL, the temp changes with the DAC value as expected. After calibration the same problem exists.
I have reseated the Actuator and Sensor boards with no improvement.
Any ideas?

Thanks
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11-3-2009 Update:

Fixed!

It was the heater rod. Measured 22-23 ohms. I replaced the rod, calibrated the HEAT TEMP CONTROL and verified that all is well.

Thanks for all the input.

This message has been edited. Last edited by: NC_cbet,

Triac in power supply.

Might be a balance chamber issue when different flow rates are set? does it change when you have the flow at 300 compared to 800?

Are your temperature sensors calibrated correctly. With machine in dialysis and your external meter hooked up, check the hydraulics screen and check both temps pre and post.

i know on the machines that i've had issue with,the battery RAM on funct bd was the culprit.had an older p/n funct bd in machine,put new batt ram chip in>not compatible with old bd so had to upgrade to new bd ,recaled everything,good to go. maybe just the RAM on your funct bd not holding cal???

I checked the temp at 37 and 39 at different 3 different flow rates, 400, 500 and 800. 400 and 500 were ok, at 800 it could not maintain a temp above 36.5.
I plan to replace the balance chamber Diaphragms. Haven't opened the chambers yet. I will post back when I do. Machine is 2-3 years old, a bit early for diaphragms, but some of the nurses leave bleach in too long, ie overnight, and this may be one of those machines.
Thanks for all the input.

You might want to check your dearation pressure or pump head.

Check heater rod resistance. I have had some that were partially burned out. They usally measure around 22 ohms when one winding burns out. Does it have any trouble reaching 80 in heat?

Let us know what you find.

Make sure when checking the heater rod, you actually pull the thing out. I've had some to ohm out at 11.4, but when pulled out they looked like they were dipped in tar they were so black. Like somebody else said, make sure your sensors are calibrated with the resistors pre and post. You might want to just stick another rod in there just for the heck of it see if anything changes. Also, FMC says the triac should ohm around 100, but even my new ones only ohm out around 75, just some info for ya, good luck.

I had something similar. Turned out to be the heater rod. Ohmed ok, but as soon as I replaced it the problem vanished.

Fixed!

It was the heater rod. Measured 22-23 ohms. I replaced the rod, calibrated the HEAT TEMP CONTROL and verified that all is well.

Thanks for all the input.

Not to discredit anyone but wouldn't checking the heater rod have been one of the first steps in troubleshooting? Are we that lazy that we can't try to find the problem on our own first. It seems if you would have you'd have fixed it right away.

I've seen a lot of crazy things on here that required help from several sources but this isn't one of them.

Ditto to what <Guest > said. Learn how to troubleshoot your problems. Ohming the heater rod was one of the first things they showed us at the level 1 class.