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mattym
06-10-2014, 09:03 PM
Hi guys got a coldroom r404a the unit ices up every 2 weeks its elec df all gas prssures are ok but i checked all perameters
Df stop temp 20
Fans active no
Def duration 20
Def cycles every 4 hours
Fan start temp 0
Its a single heater evap which works well have i missed anything when checking it over also the drain is clear any help is appreciated

Tayters
06-10-2014, 09:21 PM
Hi Matt,

Does the defrost probe read correct?
Defrost heater getting hot?

Yeah, the obvious bits I guess you've checked but this caught me out once:

Defrost heater come unclipped on the bottom of the coil (Rivacold blower). Coil heated up a bit, enough to get probe hot but back of coil not clearing, just melting a bit so a week later iced back up.

Cheers,
Andy.

cool hand fluke
06-10-2014, 09:44 PM
Hi,

Sounds like the is door being left open. Is their a door switch or curtain?
If not that I would second the defrost probe faulty or located to close to the heater bar.
After that is the controller relay stopping at temp or solenoid passing.

Grizzly
06-10-2014, 10:17 PM
Hi Matt.
Has the products that are being stored recently changed?
Only some seasonal products have High moisture contents.
Has the frequency of the through-put changed.
Even more basic Has the drain line vapour seal or the door threshold seals been damaged
Someone may have to pay for you to spend some time with this one. The answer will be their somewhere?
Have you got lazy staff that leave the door ajar whilst they load to and from the store.
Stupid it may be but the above can happen.
Sorry coolhand I have just read your post.
Great minds eh!
Grizzly

install monkey
06-10-2014, 10:49 PM
if its a walk in freezer- increase the defrost duration - to say 30 mins, just in case its not clearing all the ice, as others say check the door closes properly and the seal is compressed, also any air balance vent not closing?

had issues with a searle freezer a few mth ago- like an icy wonderland in there- blocked drain , replaced it all in 32mm plastic , no issues since ( watch me get a call out to it now!)

mattym
07-10-2014, 06:52 AM
Well i read all your posts and i know the seal is good the door os alsp self closing the drain is clear the only thing i am assuming at the minute is the chefs put cardboard boxes directly under the fans restricting the air flow

tonashp
07-10-2014, 06:05 PM
Increase the duration to 45mins. I have had similar probs with a zanotti, end temp set to +5. Make sure the probe reads good and is at the top of the coil as far from the heater on the inside of the blower if possible.
What type of blower is it?

R ALLATT
07-10-2014, 09:35 PM
What make and type of evaporator do you have

mattym
08-10-2014, 12:57 AM
I think its a luve evap

redroge
08-10-2014, 10:13 AM
Is it snow or ice on the evap.
Is there a drain down parameter if so set to 5mins.
Put through a defrost and check if there is any ice still on the evap. if there is move termination sensor to this position.

R ALLATT
08-10-2014, 10:21 PM
I would check you have the right speed evap fan motors fitted.
Fully defrost the coil put on defrost and if the controller lets you, watch what temperature the defrost probe terminates the defrost.

ABZ
09-10-2014, 10:13 PM
hi, could possibly be the liquid line solenoid valve passing .
also if an electronic controller is being used check the compressor relay isnt sticking ,seen this many times

mbc
10-10-2014, 05:04 AM
where is the position of Evap. in room . it is important .

Toolman
10-10-2014, 11:40 PM
11788 like this

or fluffy ice on back face

11789

Toolman
10-10-2014, 11:55 PM
Hi guys got a coldroom r404a the unit ices up every 2 weeks its elec df all gas prssures are ok but i checked all perameters
Df stop temp 20
Fans active no
Def duration 20
Def cycles every 4 hours
Fan start temp 0
Its a single heater evap which works well have i missed anything when checking it over also the drain is clear any help is appreciated

Some answers above are for freezer system ice ups.

But you say its a coolroom ? Sounds like a freezer setup , heaters and fans active =no

The back pressure ( LP ) must be low for it to ice up if a coolroom ?

If its not LOW then make controller work on time only not temp termination.