Ranco VXO stat problem

[davego]

I have an old Electrolux RF55 larder fridge. My previous replacement thermostat (possibly a VT9) did not have a long enough defrost cycle. I replaced it with a Ranco VXO, connected across terminals 4 and 6, leaving the extra one (3) unused. My problem is that the adjustment control does not work. In every position, including OFF, the fridge stubbornly maintains 8 deg C. Moving the capillary to the main body of the fridge gets me a steady 1 degC and no defrost. I maintain that the stat must be faulty but the supplier is reluctant to admit it.
Have I connected it up wrongly? Any other ideas?

[gegsy]

Re: Ranco VXO stat problem

Hi
As it is wired now I wouldn’t expect the compressor to turn off even in the OFF state (providing the fridge cavity is calling to be chilled) as that has no bearing on Pins 4 and 6.
The VXO has a temp range of -15C and -5C and a constant cut in of +3.5C.

To gain an accurate temp reading of a fridge or freezer cabinet, you would need to leave the door closed for a minimum of 48hours whilst a temp probe connected to a quality calibrated temperature meter is allowed to be placed midway in the cavity to be tested.

Greg

[davego]

Re: Ranco VXO stat problem

Thanks for the reply. Can you please advise how I should wire it so that the rotary adjustment control does function? The previous stat only had the two outer terminals (plus the earth ones) so there was no choice to be made, but the VXO has the central terminal 3. Should I connect to this instead of one of the other two outer ones? My fridge only has two leads plus earth so I can’t connect to all three. If the VXO isn’t suitable for my fridge can you possibly advise what is? I need the larger temperature range on the defrost cycle otherwise I cannot get an acceptable combination of cabinet temperature and defrost performance.

Many thanks

[gegsy]

Re: Ranco VXO stat problem

Hi
How you have it connected is correct. Those terminals are temperature dependant.
I am not familiar with the fridge you have but VXO is usually good for larder and fridge freezers which have no defrost elements and are not frost free.

Please unplug appliance before attempting any repair. :plug:

As for what may be suitable if VXO isn’t, I have no idea sorry.

Greg

[ELDAR59]

Re: Ranco VXO stat problem

the vxo stat runs the appliance at a higher temperature.
we haven’t used one for ages, they used to be used on some candy models years ago.
you need to replace the stat with a vt9 or equivalent, which vxo clearly isn’t.
that said, what brings you to the conclusion that the old stat didn’t have long enough defrost time?
if the old stat had been good before, you may possibly have a system fault, i.e. gas or compressor.

cheers.

[davego]

Re: Ranco VXO stat problem

The former stat , which I think was a VT9, never worked properly. Running the fridge at anything higher than setting 1 caused the evaporator to gradually ice up. The stat before that had been OK until it terminally failed , but I don’t know what spec it was. The VXO will run the fridge at about the same temperature as the prior stat at setting 1, but with good defrost performance. I would, however, like to run the fridge colder.
I still don’t understand why it doesn’t respond to the rotary control. The box even had a replacement knob and dial with numbers 1 to 6 and OFF, so it is obviously meant to have this level of control.

I’m really looking to get clarification as to whether it is faulty or not so I can get a new one from the supplier.

Thanks

[Penguin45]

Re: Ranco VXO stat problem

If you still have the original stat, please have a look at it and post up the numbers stamped on it. It may be possible to find a close match to it, despite the pukka beastie being obsolete through Lux.

Possibly your easiest solution.

Regards,
Penguin45.

[davego]

Re: Ranco VXO stat problem

The original stat failed many years ago, but the first two replacements I was sold (after regular failures) worked OK. It was only the one prior to the VXO which never defrosted properly. I bought that from a less than reputable outfit who were not interested when I took it back and tried to swap it for something that would work better. Hence my self help approach with the VXO, after I read that it had the higher temperature difference for the defrost cycle. It does and it works from that point of view. I just can’t adjust the cabinet temperature.
I did find an internet site who said they had the replacement stat for the RF55, but they wanted £45 for it which I think is somewhat excessive for what I know it is only a standard Ranco unit.

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