Waeco issue

[IBCRUSN]

We're out camping and our CF-50 will only freeze regardless of the temp setting. It acts as though it defaults to its coldest. Unfortunately I won't be able to contact Waeco USA until Monday but I figured I'd ask and see if anyone else had this happen and what the fix might be. Thanks.

 

[Bogo]

Temperature probe, or thermostat is my best guess.

 

[IBCRUSN]

Thanks for the feedback. Hopefully it's a temp probe and easy to change. Nearly all of the other electronics are in one little black box that's probably not cheap to replace. I'll touch base with Waeco this week and see if they will help T/S over the phone and sell parts, I'm not interested in shipping it.

 

[tag3]

Is it in emergency mode? That basically puts it in freeze mode.

 

[IBCRUSN]

There are no indicator lights illuminated so I'm not sure. Do their units default to freeze mode if there is a sub component failure?

I'm going to be contacting Waeco USA today to see what T/S direction I need to go.

 

[IBCRUSN]

I spoke to Dometic USA 574-294-2511 despite the dull personality the woman I spoke with was quite helpful. The gist of the T/S for my CF-50 defaulting to full cold is 2 steps:

- Verify unit is not switched to Emergency Mode (I don't have a switch on mine but CF-50's were the first model to have them)
- Disconnect the thermister from the PCB.
-----If the unit continues to run the PCB is bad. Have model & S/N handy, call # above and order parts.
-----If the unit shuts down/will not run the PCB is okay but.....bad day, thermister is bad and it's not a serviced component, replace fridge.

I'll be checking this out tonight after work. If I am unlucky enough to have a bad thermister I may search around to see where Dometic sources the thermister from or find an alternate. I'm not interested in spending $500-800 to replace it right now.

Now that I'm on a computer and not my phone I wanted to add a link to BMThikers thread. My issue seems quite similar to BMThiker's, below is a link to his thread over in the Expo section. Plus his includes all of the info for contacting Dometic in Elkhart Lake, IL and a link to his Google docs with the IPC.
https://forum.ih8mud.com/expedition-builds/549915-waeco-cf50-issues-help-wanted.html

 

[Bogo]

If you can figure out the type and resistance of the thermistor, a suitable substitute can be found.

Note, it could just be the wires to the thermistor. Most likely at the connector to the PCB, or even a corroded contact.

 

[IBCRUSN]

Well, it doesn't look good. The unit shut down when I disconnected "T". In case I incorrectly transcribed my notes I'm going to call back tomorrow and verify with another tech rep the steps I was given to walk through. If it ends up being the thermistor I have some disassembly and research to do, I'm not willing to junk what will cost at least $560 to replace just yet.

 

[Bogo]

If it is bad, then a replacement temperature controller could be used.
https://forum.ih8mud.com/showpost.php?p=7128241&postcount=17

 

[hoser]

Waeco uses a NTC 10K @ 25 Deg C type Thermistor. They can be had for $2-3/ea but access to the original location is a bit tricky. Waeco Australia offers a replacement thermistor and recommends using an alternate location for ease of installation. I don't know where exactly. The thermistor can be checked with an ohmmeter... and throwing ice in the compartment to see the resistance change.

But if there is no indicator lights functioning, I would be suspicious of the upper PCB with the display. I think this part is around $60 from Dometic.

 

[IBCRUSN]

Well, I had zero luck calling back. I was in que for 30+ mins and the woman I spoke knew nothing about the fridge, said they had no info for troubleshooting and rather than pass me along to an engineer or a real tech support agent said all I could do is take it to a local Dometic shop. Called the local shop and they have come across two compressor type fridges in the last 5-8 years, nearly all RV fridges are ammonia based. I have half a mind to call back and request to speak with the department manager to voice my opinion of their customer support. Pretty sad actually since Waeco had always been spoken highly of by the folks down under. It doesn't inspire me to purchase another Dometic product when purchase a second unit or replace this one.

Hoser, Thanks for the info. I'll have to track one down and see what I can find on Outer Limits or the other Aussie forums.

Here's the first one I found, I'll keep looking for others and post as well.
http://thegreynomads.activeboard.com/forum.spark?aBID=51933&p=3&topicID=35946015

A few days ago I started trying to gain access and remove the existing temp probe but it'll require far too much rip & tear. I believe the temp probe in installed in the crimped part of the fridge liner perpendicular to the rivet line. I think I can retrofit a new temp probe in another location without too much drama and at this point it's worth a shot.

 

[IBCRUSN]

It sounds as though it was a $25 part in Oz. Here's some more info from the blokes in Oz:

http://thegreynomads.activeboard.com/t34862733/waeco-cdf-40/
http://www.exploroz.com/Forum/Topic/53006/Waeco_CF50_Thermistor.aspx?fq=53006
http://forums.overlander.com.au/viewtopic.php?p=903815&sid=dd7494af1e92ffa111ce966a04c1ea03

Although not one of the smaller CF Waeco's the idea is the same. It's a bit slow but the steps appear correct.
http://youtu.be/-YgHh7rioco

 

[IBCRUSN]

Well, I've ordered a handful of generic thermistors w/ 200mm leads from Mouser and I'm going to try and order the Waeco thermistor next week. If I'm lucky I'll be able to splice in the generic thermistor and add the Waeco unit as a second spare ready to go for the next future failure.

It's two years old but the Waeco P/N = THERMIST-L

 

[hoser]

Any luck with the replacement thermistors?

 

[nuclearlemon]

got the thermistors kris. hope to get to mine this weekend maybe.

for others who have issues, in all your searching, have you found that this is a "universal" fix for waeco's, as in, does it work on all generations (mine is an older mobicool branded cf35, for tech purposes)?

 

[sashay567]

I use a CF50 aboard my sailboat. I too have experienced the thermistor issue and was not able to obtain one from Dometic as they say it is not a servicable part. I bought a generic 10K thermistor from Digi-Key and installed it by following the procedure from the Aussie Caravaner's Forum.

After dropping the compressor down to gain room to work, I used a hole saw with the pilot bit set very shallow to drill a 1" hole, 4" in and 1" down in the compressor compartment on the left side as you face the compressor end of the CF50. I took care to only drill the hole through the plastic only. A steak knife was used to remove the foam insulation down to the evaporator. The thermistor was attached to the evaporator plate using a piece of adhesive foam tape. The hole in the insulation was filled with spray foam from Ace hardware.

The CF50 manual states the tempurature with the stock thermistor is "that of the middle of the interior". I am sure the thermistor replacement being placed against the evaporator is reading the evap temp, not the interior temp. Evap temps are much colder than the interior temp for any given temp setting. For example, with the CF50 temp set to 20 degrees, the thermometer inside the box was reading 35 degrees. I let the CF50 run for 24 hours with the same difference in temp noted. The CF50 did cycle on and off as before.

I ordered a second thermistor. The second thermistor was temporarily connected to the control circuit board in place of the replacement. I placed the second thermistor in the middle of the interior. Temp readings between the CF50 display and the standalone thermometer are now nearly the same. The CF50 seems to operate as it did before the stock thermistor failed. The downside is the thermistor is exposed in the middle of the interior box.

Based on the above, there may be no need to place the thermistor up against the evaporator - no risky surgery needed. I haven't figured out exactly how to route the thermistor wires to the control board yet but will document and post here when I figure it out. Hope that helps.

 

[BMThiker]

probably more than you want to read, but I went through a handful of issues with my CF50. Documented here: https://forum.ih8mud.com/expedition-builds/549915-waeco-cf50-issues-help-wanted.html

Maybe you'll find some tech in there that is helpful. After I replaced the $50 main PCB, it cleared up all my issues. Finicky little bastard.

 

[IBCRUSN]

Rick, Great thanks. I included a link above just so we all have an easy way to cross reference the info everyone has contributed. I'm pretty sure my issue is the thermistor but with your experience, Ige's mess, mine and all the links in both threads it'll be a great resource for folks that have issues with Dometic and Waeco branded fridges. Whenever I get around to working on my unit I'll post up the results.

 

[sashay567]

Fixed

OK, here is what I ended up doing to fix my CF50. I ordered a 10K @ 25 degrees C Carel NTC themistor from rparts.com. The reason I picked the Carel themistor is that it is epoxy encased and appears to be very rugged. There are 2 of these same thermistors controlling the compressor my built in 5 cu/ft reefer aboard my boat, 1 senses the interior box temp for display, and the other senses the evaporator plate temperature to control the compressor. The link to rparts.com Carel temp probe: http://www.rparts.com/index.php?cPath=13_17_42&osCsid=mvftdohqem4fhpi0c9heush6a5

Picture of probe:
[URL="http://i356.photobucket.com/albums/oo2/sashay567/DSCN2396.jpg"][URL="http://i356.photobucket.com/albums/oo2/sashay567/DSCN2396.jpg"][URL="http://i356.photobucket.com/albums/oo2/sashay567/DSCN2396.jpg"][/URL][/URL][/URL]

Next, I drilled a 1/4 inch hole inside the dairy compartment through to the passage way for the wiring to the temp display and control board. A rubber grommet was installed in the hole and the temp probe wires were theaded through and connected to the control board:

[URL="http://i356.photobucket.com/albums/oo2/sashay567/DSCN2395.jpg"][URL="http://i356.photobucket.com/albums/oo2/sashay567/DSCN2395.jpg"][URL="http://i356.photobucket.com/albums/oo2/sashay567/DSCN2395.jpg"][/URL][/URL][/URL]
You can see the temperature probe wires coming in from the right.

To use, place the temp probe in the middle of the box horizontally and vertically. I use my CF50 primarily as a freezer so the probe is placed between layers of frozen food as close to the middle of the box as practical. The probe appears to be rugged enough to use this way as long as some care is taken.

Hope that helps,
Rodney Kidd
Sailing Vessel Sashay
Alameda, CA

 

[nuclearlemon]

so, finally getting time to tear into my fridge. not going well. i always felt that my fridge was far older and going to be not quite like the rest....i feared correctly. the bottom doesn't appear to come off, at least not with a lot of work. it doesn't just wrap all the way up the sides, it's sealed.

thermisters...yeah, good luck finding them.

the $98 i spent on main and display pc boards are even wrong...close, but no cigar and i will re-emphasize that dometic us's customer service sucks, since i told them multiple times that this was an old mobicool made cf35, with a light display not a digital one, and gave them the serial number on at least three occasions. let's not even bring up the months (yes, months, as in five) that it took to get the pc boards.

sooooo close to getting a fridge made by a company that has customer service. i will dick with this one a bit more and try the local repairman (ok, 80mile away) repairman first, but here's what i'm working with.

anyone need a main pc board with matching diplay pc board...for sale cheap.