SJ-Chris wrote:

. . . I would guess the Fridge Defend is designed such that you can adjust those temperature settings for detecting high temp . . .
-Chris

dougrainer wrote:

Chris, My comments come from 43 years as a RV technician. ALL are solid based on MY travels and what I have seen about RVer parked at roadside areas and eateries and even in neighborhoods. TRAVELING on slopes and inclines does NOT cause an out of level problem as the movement overcomes the problem of the Ammonia system. The overheat disc is a SAFETY install. Has nothing to do with stopping a potential blocking problem. IF the out of level or even a large blockage happens, running the Refer, can cause a burst of a cooling unit at its weakest points. IF on LP, the flame can ignite the spewing ammonia and cause a fire. So after lawyers sued Dometic and Norcold 25 years ago, both installed overheat disc's. There was a massive recall over 20 years ago for millions of refers to have the overheat kits installed. ALL new refers since then had the kits installed at build. Doug

otrfun wrote:

The Fridge Defend high-temp cut-off is adjustable (at least on v4 and v5). Instructions how to adjust it can be downloaded at the FD website.

The FD logs the maximum boiler temp and number of times the high-temp cut-off has activated (since the last user reset). The boiler temps on our Dometic DM2663 typically hover between 185-190c/365f-374f (on propane, 120vac, and 12vdc). After a year or so of travel with zero effort to make sure our truck camper was level, the FD logged a max boiler temp of 207c/405f (we reset it). Just to be on the safe side we also reset/lowered the factory default high temp cut-off from 217c/423f to 202c/396f. After another two years of travel, max boiler temp has only risen as high as 197c/387f. Lastly, just to make sure all was well after all these resets, we manually heated the FD boiler sensor above the high-temp cut-off. The FD cut-off 12vdc power to the fridge control board and logged it.

JBarca wrote:

Chris, I have been following your post.

I did review the ARP system a while back, just never made it to installing any, yet. I called and talked with them today. They are very down to earth, and they are a, know what they are doing company.

JBarca wrote:


I am going with the Fridge Defend V5.11 with the fan control. I want to add the defrost fans inside the fridge and to cycle them you need the fan control version. The V5.11 has an alarm, so you know when you have a problem and you and tweak the settings as needed. Since most all the fridges I work on are older, there may be some level of coolant damage from prior owners, so the fridge may have limited life, but having the fire safety part is a big plus.

JBarca wrote:



Since I already have a fan up on the roof vent and a thermal disk switch to turn it on and off, I may switch the roof vent fan to the Fridge Defend. You just parallel the inside defrost fans with the roof vent fans. The ARP fan relay is rated at 20 amps, plenty for the milli amp fans I use, and the ARP defrost fans.

JBarca wrote:


Another reason for the Fridge Defend not yet mentioned is cold weather. I know you may not camp in cold down to freezing, and below, but in our area, freezing temps are here and we do winter camp.

If you want to get close to 32F outside or go below, the fridge as it stands in the stock configuration will slow down and may stop working. The heating may not stop, but the fluid can slow down flowing from what I have read. It seems Dometic does offer a lower vent hood that has some blocked off vents to lower the amount of cold air entering.

This Dometic lower vent is made for cold weather, just they do not list much else or fit the older Dometic vent frames. Norcold sells a cold weather kit to heat up a certain return tube on the cooling coil. Here is one of them. https://www.amazon.com/Norcold-634913-Cold-Weather-Kit/dp/B00T36VI30

I have not been able to find Dometic offering that heat strip. By using the heat strip on the Norcold and helping to reduce the cold air intake, it is reported you can go down to 0F. Some folks use an incandescent light bulb in the outside compartment.

The ARP system will help to shut off the boiler heat if the coolant stops flowing due to the cold weather for any reason.

Doug may be able to add some more to this and if he knows if Dometic offers a cold weather kit or do you just use the Norcold one? Most all of the older campers I restore have RM2652 fridges that I service.

Thanks

John

SJ-Chris wrote:

. . . I'm a DIYer and I enjoy tinkering with modifications . . . I believe a simple high temp thermostat can easily accomplish this task, and they only cost $20. If I only had 1 RV I would probably still just buy a Fridge Defend. But I've got 3 RVs. So if I can implement this DIY fix it will save me 3x the money.

otrfun wrote:

Have you found a suitable 200c sensor and control board combination that operates on 12vdc? IMO realworld temperature accuracy and overall, proven reliability may potentially be the biggest hurdle.

Who wouldn't love a reliable, low-cost alternative to the $200+ FD?!