Trying to find a fridge issue with inconsistent function

[SailorMcCruise]

Thanks again. So i had the unit running with a bypassed thermostat for more than 24 hours and except a quite hot compressor, there is no difference. The voltage is fine around 13 V.
I guess I am at the end of my abilities for now.
thanks again!

[Richard Kollmann]

Volt meter reading of 13 volts as I indicated before is meaningless on a compressor that runs on modified AC pulses. Less than 11 volts would indicate a voltage problem.

A hot compressor that ran for 24 hours with thermostat bypassed and no cooling could indicate a restriction and too much refrigerant. If refrigerant flow is blocked with correct amount of refrigerant compressor would only get warm as the amperage draw would be around 3 amps. If low on refrigerant amperage draw would be less than 3 psi.


You now know compressor is confirmed to be working under a load because it got hot. I recommend you install a bypass ground wire from module to to battery.

You indicated that there was a time after cooling stopped that evaporator started cooling again.

[SailorMcCruise]

ok, will install a bypass ground and report back. Thanks!

[Richard Kollmann]

The Frigoboat Frigomatic Madrid 35 F and its horizontal fan cooled condenser design makes it difficult to keep condenser fins clean. Are you sure that there is no cooling in evaporator not even cold condensation? With that closed in condenser shroud can you see if condenser air flow is unrestricted by dust and hair? Still looking for why compressor is hot and no evaporator cooling with at least a small amount of frost somewhere.

[stevensuf]

I had similar issues on my boat when the coolant gas levels got low, on one tack the fridge would just now work, once level it would work again, given a bit of time for the coolant to settle, occasionally in rocky anchorages it would go off and we had to switch off and let the gas settle. get the coolant topped up.

[SailorMcCruise]

Are you sure that there is no cooling in evaporator not even cold condensation?

No, there is cooling, but very very little and lot of condensation moisture due to the high temperatures and humidity here.
I did install a separate ground cable and let the system run over night, but no difference.
So as a recap of the status quo:
Compressor and fan running. Voltage ok. No error codes.
Evaporator cool to the touch with condensing water but no ice.
Sometimes without any reason system starts to work nornally with evaporator covered in thick frost and ice. Then system back to barely cooling.
Since the boat is a monohull, i was wondering about the effect of the on the system.
With all gathered Information so far, I‘d also guess lack of coolant.

[Richard Kollmann]

Compressor running continuous No frost anywhere on evaporator but evaporator covered with cold moisture condensation. Run compressor until this condition assists again and check to see if you hear a gurgling or hissing sound inside box. If no noise is heard turn off compressor and listen for several minutes for ice if there is any in cap tube to melt and hissing sound to return temperately. If there is moisture in refrigerant it freezes and thaws in cap tube cycling cooling and temperature of evaporator at 34 degrees F on your type system.

[wingless]

This topic shows my Danfoss compressor problem.

[SailorMcCruise]

Soooo. I guess the assumption of some posters is right and I might have a contaminated coolant. when i turn the system off and wait a bit, then turn it on again I can hear some gargling which soon stops after the area where the coolant pipe joins the evaporator cools down. i can then put my hand on the cold spot to make it thaw a bit and gargle again.
Seems a refill is neccessary?

[s/v Jedi]

Originally Posted by SailorMcCruise

Soooo. I guess the assumption of some posters is right and I might have a contaminated coolant. when i turn the system off and wait a bit, then turn it on again I can hear some gargling which soon stops after the area where the coolant pipe joins the evaporator cools down. i can then put my hand on the cold spot to make it thaw a bit and gargle again.
Seems a refill is neccessary?

Glad you finally stuck your head in there to listen

Now that you have confirmed that the flow stops when not cooling, you need to confirm if it is moisture freezing at the capillary tube. If you have no heat gun nor hair dryer then take a ziplock bag and fill it with hot (not too hot, warm) water and hold that against the coldest parts of the evaporator plate while the unit is running but no gurgling sounds. If you can make it flow again (by defrosting that spot) then let it flow and see if it freezes again and flow stops. Try the hot bag again to start flow. If this is repeatable then you have confirmed refrigerant contamination. It then is time to find the leak.

In the mean time, you may be able to coach the system into cooling again by keeping at it with the hot bag. It may just move the moisture away to a point it doesn't block the circuit and take a long while to assemble at the cap tube again. This may get you to help. I've learned that it's best to keep a gauge set, some refrigerant (the small bottles with fill valve) and vacuum pump aboard. It had sold it once but bought a new one years later when my O-rings started leaking.

EDIT: the hot bag because it is much more effective and will bring flow back to full while warming with hands is only so-so.

[SailorMcCruise]

aye sir.