Refrigerator...Scratching My Head...

[Nick in Manitou]

Ref: Summit Brand Refrigerator, Model HS2961 (This is a unit with NO freezer.)
(The new equivalent model is FFAR10, the company is now called the AccuCold Division of Felix Storch) The compressor is an Embraco EMU 45HSC


When we bought the boat a little over a year ago the refrigerator had an issue that the previous owner had just put up with…it would freeze stuff.

I called the local authorized service folks and never could get a response from them. So I contacted another local appliance repair technician who came highly recommended.

When I told him the problem I was having, he said that it was most likely a defective thermostat. To test it, he said I should set the thermostat to the warmest setting, and after a half an hour, if the compressor is still running, use the plastic handle of a screwdriver to whack the knob of the thermostat. Then if the compressor shuts off that indicates that the thermostat is sticking and needs to be replaced.

Sounds simple enough. So I did as instructed and sure enough the machine stopped running with just a whack of the screwdriver!

I ordered a new thermostat from the manufacturer and when I received it was excited to install it and not have frozen food in the fridge (remember it is a unit that does not have a freezer compartment).

Unfortunately, the problem continued with no change in the symptoms. The temperature in the fridge would fall into the twenties if one didn’t whack it. So, I assumed that the replacement thermostat was defective. The tech support folks at the manufacturer couldn’t think of anything that would have the symptoms that this unit was displaying except for a defective thermostat and eventually agreed to send me a replacement unit for the replacement unit.

3^rd thermostat installed with no improvement!

The wiring up near the top of the inside of the case where the thermostat is located is very minimal with just the door light switch and the thermostat…all the other electrical stuff is at the bottom under the machine. Because of the fact that there is only the light switch and the thermostat up in the area where I am tapping on the knob of the thermostat and because I have checked, metered, and re-squashed all the crimp fittings that exist up there, I am at a loss for what might be causing the issue.

This unit has no fans that are run to cool the coils or to defrost the unit. There is no defrost cycle. Any ice that has formed inside the unit melts and drains out when the compressor is off.

I am not an electronics person, but it seems to me that the only reasonable thing left is that when I smack the thermostat knob that perhaps the contacts in the thermostat actually make-and-break a bit and that sends a pulse down to something in the start relay unit mounted to the side of the compressor.

I am attaching the schematic for the unit. After examining the wiring, I am amazed that the system is so simple.

If anyone out there is a refrigerator technician or has reasonable suggestions as to what I might do to fix this thing, I would appreciate it.

I called the technician who suggested the screwdriver-whack test and told him what the situation was and he said that perhaps I should purchase another refrigerator!

I don’t really want to spend the money for a new unit if I can avoid it, plus getting the new unit all the way down the pier, down the ramp, along a bunch more pier, around a few corners, up a set of stairs hanging off the side of the boat, removing the door and probably some components of the interior of the boat, all sound like even more trouble than living with a unit that wants to freeze everything.

A couple more photos in the following post in case they can assist someone in coming up with an insight as to what the problem (and solution) might be.

Nick

[Nick in Manitou]

A couple more photos...

[Byresch]

A couple more photos...

I am going to make a suggestion that goes in a different way. I had a similar problem with a refrigerator and it turn out it had lost its Freon charge and keep on running and freezing. I don't know if this is your problem but mine was a very old frig and we replaced it on the boat.

[madhatter1]

first, be thankful that you have a super simple electro-mechanical control system with what seems like a faulty factory supplied thermostat.

Now it look like you have a nice looking fridge. Just get a qualified refrigeration guy to set up a good stat and move on. If you were at the mercy of crappy electronics and sensors this would not be an option and you would be really screwed. Your schematic shows as this is simple and possible.

[Nick in Manitou]

Bryon,
I would assume that if the freon was low, the compressor would not stop running when the thermostat was whacked by a screwdriver handle. I'm just guessing...

If I am incorrect, please let me know!

MadHatter1,
I am sure that it is possible that we have had three (3!) defective thermostats in a row, but I would assume that the odds are pretty much against it. I really had to push hard on the factory to accept that possibility that the one they sent me was defective.

If I can't get a good thermostat from the factory, where might I find one that would work in this unit?

Do you think that it could be my installation technique? It seems pretty straight forward. Disconnect the old unit, pull it out, thread the capillary tube into the sleeve the old one came out of, reconnect the wires and put things back together.

I certainly would be willing to pay a technician for a service call, but at this point, I am afraid that he would come out, install yet another thermostat, and I would have the same problem. If someone knows of a good service person in the bay area who might be able to solve this issue, I would be pleased to give him some business. When the last service guy suggested that I replace the refrigerator I really lost faith in the trade.

Thanks for the thoughts
Nick

[dottieshusband]

Not familiar with your model, but they all work about the same. All refrigerators go through a defrost cycle to remove accumulated condenser coil frost. That usually involves a timer, heating coils, a drain line, and an evaporator fan or drip pan. I've found the most common cause of your problem is a blocked drain line. Failed timer is next, and rarely the defrost heater. When the defrost cycle kicks in, if the melted frost can't drain away, it very quickly ices back up.

[Nick in Manitou]

Dottieshusband
This refrigerator seems even more basic. There is no defrost cycle, no defrost heater etc. There are no fans for the compression or expansion coils and no active defrost cycle.
The manual states,
"The refrigerator defrosts automatically. While the compressor is operating, ice deposits on the inner back wall; later, when the compressor is not operating, the ice melts. Water drops collect and drain through the outlet in the inner back wall into the drain pan situated above the compressor. There the water evaporates."

This is one of the reasons that this is driving me crazy...there is hardly anything that can break.

If it is not the thermostat, what else can it be? (The symptoms have been exactly the same through three thermostats.)

Bryon (Byresch) suggested low freon, but if that was the case why would whacking the thermostat turn the compressor off for a few hours?

Left to do its own thing, the temperature in the fridge can drop into the 20s with the compressor continuing to run. Whack the thermostat and it quits until the temp gets up to around 42 or so and the compressor kicks back in (that is with the thermostat turned all the way to the warmest setting).

???
Nick

[HahnR]

Nick,

We have a Summit refrigerator/freezer and a beverage cooler. The beverage cooler began to run warmer than the temp setting by a couple degrees, & steadily got worse until it was 8 deg warmer than the temp setting. After consulting with our Summit dealer who themselves consulted directly with Summit, they determined we had a defective thermostat, so we ordered one. It was late in the season by that time so I decided I would install it last spring. After winter storage, I powered it on & it was spot on with the temp and worked flawlessly. Later, we had to have our Starboard engine rebuilt again, & had a significant list while the heads & kits were off the boat & other parts on the port side of the boat. The same problem cropped up with the beverage cooler again. A week later the engine was back together, the list was gone and the beverage cooler was 8 degrees warmer than the temp setting. I powered it off, propped the door open and left it overnight. The next morning I powered it on & closed the door. It came down to proper temp & worked flawlessly again. The new thermostat is still in the box unused along with my other spare parts.

Last summer our refrigerator began freezing everything. We set the temp at 45 deg & it still froze everything. I got a wild hair, powered it off and propped the door open overnight. The next morning,, I powered it on & closed the door. It worked flawlessly the rest of the season.

Sorry for the long response, but we had 2 different problems with 2 different appliances and both were solved by powering them off & propping the door open overnight. I sure couldn't come up with an explanation & neither have the Summit people, but both worked fine afterwards. If you haven't already, I would definitely try doing that. BTW, neither one had any sign of frost buildup anywhere and the coils on both were clear and clean.

Maybe you can have the same luck,

Randy

[Nick in Manitou]

Randy,

That is certainly an approach that I had not thought of!

But I will see if we can arrange our food such that we can give it a try!

I wonder if there is someone on the forum who could give us a logical reason for your success.

If I can convince the cook (my wife) that things will survive the night in a cooler (or two) it would be at least as productive as continuing to sit here Scratching My Head.

It might take a day or two to locate another cooler here on the pier, but I will report back if I get a chance to check it out!

Nick

[kingsley_oasis]

Such a basic system as per drawing.
If you have the old thermostat, break it open and see if it has mechanical contacts as drawing implies. Inspect and see if they have been arching, which could cause them to stick closed, and hence the tap with screwdriver is enough to jar them free. Of course if that is the problem you then need to find the cause of the arching. Bad start relay, capacitor, motor, bad connection etc. I would measure voltage and current draw during start and steady load also.

Could it be that the pocket where capillary bulb is located has some form of insulation issue and does not accurately see the interior temp.

You could also test thermostat/s using multi meter, and put capillary tube bulb in cup of iced water. slowly add warm water or ice and with thermometer in the water and you can find the make and break values.