mccall reach in building ice

[Pneuma]

I have a mccall reach in freezer. It is buildign ice on the evaporator box wall farthest from the evaporator, the ice then melts, I suppose during defrost and then runs down and starts to drip through the fan opening, unfortuantely an icicle forms and stops the fan from turning and it loses temp. I can't see why ice is building up on that part of the evaporator box. Anyone seen something similar? Thanks

[tipsrfine]

Without being able to see it I'd have to say a posible air leak. Warm humid air getting zapped frozen.

[VTP99]

Yep just had that problem on a w/i freezer. Door closer not closing completely.

[itsiceman]

I have a mccall reach in freezer. It is buildign ice on the evaporator box wall farthest from the evaporator, the ice then melts, I suppose during defrost and then runs down and starts to drip through the fan opening, unfortuantely an icicle forms and stops the fan from turning and it loses temp. I can't see why ice is building up on that part of the evaporator box. Anyone seen something similar? Thanks Nothing is far away inside that box
They got that thing cramed in real good :(

I think the time I saw this the box was leining foreward and the door hinge cams were striped out

[shephvac]

Door gaskets not sealing?

Is it the coil or sheet metal next to the end bends icing? Check charge if coil, check air flow if sheet metal.

Does it have an electric heater in the drain pan and is the box leaning toward the drain?

Just some ideas.

[selfemployed]

If it's white frost, sounds like an air leak or vacuum breaker ( if it has one ) leaking. If it's water droplets frozen and then melting, sounds like to long a defrost. Bad fan int. / temp. term. switch

[Pneuma]

If it's white frost, sounds like an air leak or vacuum breaker ( if it has one ) leaking. If it's water droplets frozen and then melting, sounds like to long a defrost. Bad fan int. / temp. term. switch

it's not frost, it is ice. The door seal looks good and the door closes, although I get reports of people finding it it cracked, but when I test it it closes fine. I did check the pan heater and made sure the drain line was open about a month ago and all that was good.

One theory I have is that the ice build up is opposite the suction valve on the compressor. Which is not totally insulated. So you get an ice ball around the valve which mightr be in contact with the outside of the box. So the theory is this makes a cold spot on the box that the water vapor from the defrost condenses on. I don't know if that makes sense but something I want to look at.

Thanks for the tip on the fan int. temp term. control. I'm not familiar enough with the cycle to know how that would affect this problem, but i'll take your word for it and when I look at the diagram I'm sure it will be clear.

The first time I worked on this I found the wiring bundle was laying against the evap. and it looked like it was just a place to build an ice bridge, so I secured it away from the coil, but the prob came back.

Thanks for the help. I'll let you guys know how it works out. :callpro:

[VTP99]

Check X terminal at time clock.

[selfemployed]

Check X terminal at time clock.

Ditto

[czipa]

Check drain gutter running across back of bunker to drain, Ihad one doing same thing and found water leaking between gutter and bunker wall and slowly building up ice. I sealed it with silicone, no problem since 2 years now

[Pneuma]

Got bqack today for a while. The timer initiates and terminates fine. The termination time is 20 minutes. I have no way to judge how long it soud be, I shortened it to 10 minutes. On the diagram is a heater limit. Does this funtion as a temperature termination or just to keep the heaters from burning up? If it's for temrination that could very well be the problem.

BTW the model number is 4-4020F

[nchvac]

.

[VTP99]

Pneuma,
The three wire klixon is your fan delay & defrost termination. The inter dial on your time clock is for the maximum defrost time usually set at about 40 min. The brown wire on that klixon normally goes to your X terminal to terminate defrost.The red is power in or common & black is to the fan(s). The two wire heater limit is as it says. Just a safety. When the coil reaches say 55* that brown wire energizes the X terminal to terminate defrost then once the coil gets down to say 34* the black wire will power up the fan(s) Hope this helps you out. :patriot:

[Pneuma]

Pneuma,
The three wire klixon is your fan delay & defrost termination. The inter dial on your time clock is for the maximum defrost time usually set at about 40 min. The brown wire on that klixon normally goes to your X terminal to terminate defrost.The red is power in or common & black is to the fan(s). The two wire heater limit is as it says. Just a safety. When the coil reaches say 55* that brown wire energizes the X terminal to terminate defrost then once the coil gets down to say 34* the black wire will power up the fan(s) Hope this helps you out. :patriot:

Thanks for the information. The diagram is not very good at conveying what you are telling me. The fan delay seems to work as described in the manual, after a defrost cycle it delays the fan so warm air does not blow on the product. Now to me this looks like a timer and not a temperature switch, just looking at the diagram, so you are saying this is actually a temperature switch that opens at 55 and closes at 34. If this is the case, the fan does wait for a delay after a defrost so I have to assume this control is working and the problem is elsewhere.

[tipsrfine]

Thanks for the information. The diagram is not very good at conveying what you are telling me. The fan delay seems to work as described in the manual, after a defrost cycle it delays the fan so warm air does not blow on the product. Now to me this looks like a timer and not a temperature switch, just looking at the diagram, so you are saying this is actually a temperature switch that opens at 55 and closes at 34. If this is the case, the fan does wait for a delay after a defrost so I have to assume this control is working and the problem is elsewhere.

This is one of those times where a picture really would be worth a thousand words. The Nextel i580 phone has a camera with its own spotlight.

[VTP99]

Pneuma,
Do you have three wires on that switch & is it mounted to the evaporator or line ?

[itsiceman]

Was it iced like this Pneuma ?
New hinges and leveling the box took care of this one.

[Pneuma]

Was it iced like this Pneuma ?
New hinges and leveling the box took care of this one.

No the ice is clear it forms on the inside of the evaporator box on the sideof the box that air leaving the coil would hit it, up near where the top snaps on. Then it sort of runs down and forms like an icicle drip and eventually a smaller icicle forms as the water tries to drip out the hole around the fan and keeps the fan from spinning. There is even a little ice puddle inside that air diffuser, the deal with the round holes in your picture.

I got a three wire klixon on will call, I just didn't have time to get to it today. I will take some pics when I go over there in any case.

[VTP99]

Pneuma,
On that 3 wire klixon remember that power in is RED and at 55* sends power to BROWN & X terminal to terminate defrost. Could be any amount of time. At 34* switches over to BLACK to power up fan or fans. Good Luck :CU:

[itsiceman]

No the ice is clear it forms on the inside of the evaporator box on the sideof the box that air leaving the coil would hit it, up near where the top snaps on. Then it sort of runs down and forms like an icicle drip and eventually a smaller icicle forms as the water tries to drip out the hole around the fan and keeps the fan from spinning. There is even a little ice puddle inside that air diffuser, the deal with the round holes in your picture.

I got a three wire klixon on will call, I just didn't have time to get to it today. I will take some pics when I go over there in any case.That one was extreme but did have clear ice up by the fan and up the wall and to the coil with frosted snow cone ice. Because it was leaning forward water was dripping from the drain pan and down to the fan but was hard to see because of all the other leftover (defrost missed) ice build up at the coil because the door wasn't closing. You know you can test the klixon with a thermometer right ? :angel:
Everything is a beyatch to change on that unit :.02:
FWIW I've had more than a few heater elements go bad on those units for some reason.

[Pneuma]

I'm going to check the existing with my meter before I change it, but I want to have it with me. The folks tell me sometimes the door doesn't close, but the closures work fine. Thanks for all the tips, I'll post results and pics on Monday!

[FarleyRedfield]

I see 2 possibility's
1 already mentioned is the fan limit. The problem could be the fans coming on early before water & vapor have had long enough exposure to below freezing temp to refreeze and thus stay off the wall and on the evap. Evidently the defrost is adequate from your description and the limit part of the switch is ok. The trouble Im talking about is the FAN part of the switch which I believe is not at low enough temperature. Your meter will not be able to tell you if this is happening or not. This would require a specialized testing tool Im not aware of. Because you have to be at or slightly below freezing of the evaporator before the fan event happens. Now this is a 3 wire Im talking about, but a 2 wire would be the same but its separate from the defrost limit. If you have 2 - 2 wire switches Id think seriously about changing both wile in side. I recommend just change it then watch it next day or 2 will tell. This is all assuming that it has these type controls.

2 Less likely problem from your description is water setting in the drain pan after defrost. TRUE brand reach in freezers have a drain tube heater to keep the drainpipe open and if this drain tube heater goes out the pan and drain will freeze solid (slightly different description that what you give). This heater on TRUE models is on all the time. Interested in what you find. My money is on the fan limit switch.

[tipsrfine]

I see 2 possibility's
1 already mentioned is the fan limit. The problem could be the fans coming on early before water & vapor have had long enough exposure to below freezing temp to refreeze and thus stay off the wall and on the evap. Evidently the defrost is adequate from your description and the limit part of the switch is ok. The trouble Im talking about is the FAN part of the switch which I believe is not at low enough temperature. Your meter will not be able to tell you if this is happening or not. This would require a specialized testing tool Im not aware of. Because you have to be at or slightly below freezing of the evaporator before the fan event happens. Now this is a 3 wire Im talking about, but a 2 wire would be the same but its separate from the defrost limit. If you have 2 - 2 wire switches Id think seriously about changing both wile in side. I recommend just change it then watch it next day or 2 will tell. This is all assuming that it has these type controls.

2 Less likely problem from your description is water setting in the drain pan after defrost. TRUE brand reach in freezers have a drain tube heater to keep the drainpipe open and if this drain tube heater goes out the pan and drain will freeze solid (slightly different description that what you give). This heater on TRUE models is on all the time. Interested in what you find. My money is on the fan limit switch.

No the ice is clear it forms on the inside of the evaporator box on the sideof the box that air leaving the coil would hit it, up near where the top snaps on.

The ice spot IMO is too specific (opposite suction valve) and too dense to be a result of the fan comming on too soon. I highlighted in red what I think is posibly the key clue, w/o photos there is no telling, but if this evaporator box is the kind that sits on top of the reach-in and has a top that "snaps on", then I'm leaning towards the limit side of the fan/limit switch failing rather than the fan side of the switch. Along with a leaking gasket on the "top" where the ice is forming. Solid ice means frozen water which means it's getting too hot in that box. The OP has stated it stayed in defrost the whole 20 minutes, rather than being terminated by temp of coil.

[itsiceman]

The trouble Im talking about is the FAN part of the switch which I believe is not at low enough temperature. Your meter will not be able to tell you if this is happening or not. This would require a specialized testing tool Im not aware of.

I'm lost. Whatcha talking about FR :confused:
Your not taking temps with a T87 are ya ?

[FarleyRedfield]

No the ice is clear it forms on the inside of the evaporator box on the sideof the box that air leaving the coil would hit it, up near where the top snaps on.

The ice spot IMO is too specific (opposite suction valve) and too dense to be a result of the fan comming on too soon. I highlighted in red what I think is posibly the key clue, w/o photos there is no telling, but if this evaporator box is the kind that sits on top of the reach-in and has a top that "snaps on", then I'm leaning towards the limit side of the fan/limit switch failing rather than the fan side of the switch. Along with a leaking gasket on the "top" where the ice is forming. Solid ice means frozen water which means it's from getting too hot in that box. The OP has stated it stayed in defrost the whole 20 minutes, rather than being terminated by temp of coil.

yes I have seen a freeze up on an extended top box type evaporator. Believe maybe the outer metal separated from the insulation and the condensate froze inside and out on the one I saw. If I now understand the equipment andyou happen to be correct in the design then yes I would steer away from a def / fan limit at least on the fan side problem I was thinking about.

I wonder is there an accumulation of water on the floor or outside of this box? Is the evap box extended above the refrigerated space like poster above describes? Is there frost - Ice on the suction line? Does this system use TXV? DO you know super heat on system ?

[FarleyRedfield]

I'm lost. Whatcha talking about FR :confused:
Your not taking temps with a T87 are ya ?

I think Im not clear on the type of evap setup is on this box. I may be confusing you because Im confused. then again imin the greatest state of confusion ... Oklahoma. Let me see who else is reading and what else is said I may have said too much. Feet of mine taste nasty keep em in my mouth most days.

[FarleyRedfield]

I'm going to check the existing with my meter before I change it, but I want to have it with me. The folks tell me sometimes the door doesn't close, but the closures work fine. Thanks for all the tips, I'll post results and pics on Monday!

Just wondering if this evaporator is setting on top of the box as someone else has pointed out to me? And if so I jaus have to ask because you say the door dosnt close sometimes... Does it have an internal air pressure relief valve? This is sometimes also on extended top evaporators and if not closing all the way it could allow Ice to form. If so equipped, Is it operating correctly? Relieving when the door closes? And resealing?

[Pneuma]

The OP has stated it stayed in defrost the whole 20 minutes, rather than being terminated by temp of coil.

If I said that I mispoke. I have not confirmed the three wire does not terminate defrost. I'm going to verify that tromorrow. I did say the timer was set at a 20 minute termination time.

[Pneuma]

yes I have seen a freeze up on an extended top box type evaporator. Believe maybe the outer metal separated from the insulation and the condensate froze inside and out on the one I saw. If I now understand the equipment andyou happen to be correct in the design then yes I would steer away from a def / fan limit at least on the fan side problem I was thinking about.

I wonder is there an accumulation of water on the floor or outside of this box? Is the evap box extended above the refrigerated space like poster above describes? Is there frost - Ice on the suction line? Does this system use TXV? DO you know super heat on system ?

No ice on the floor, uses a TXV, suction line has ice where the insulation is torn and the suction valve has an ice ball as it is not insulated, this is just opposite of where the ice forms inside the box. I have not checked the refrigeration circuit, ice on the suction line of freezer seems normal to me, if the box is 10 degrees the suction line has got to be cooler than that and so it will freeze. Nothing I have found suggest to me to put gauges on it, but I don't work on refrigaeration very much.

Also I did amp the pan heater and the evap heater and I ran water in the drain pan and watched in run into the condensate "evaporative tray" for lack of knowing what you call it. All that worked ok, this was the first time I tried to troubleshoot it. I also had found a bundle of wires in contact with the evaporator, a plastic ring that held the wires had broken. I thought this was creating a bridge for ice to form where the heater could not get to it, but after securing the wires back, I still have the problem.

I plan to take the klixon out tomorow and test it in ice water and also in some luke water, around 55 based on what is posted here and see if it is doing it's thing.

[itsiceman]

Don't take it apart if you don't have to. Its a pita.
Just test it in place with a thermometer. Compressor running for the low event (fans) and defrost runnung for the high event (termination).
Ice water wil not be cold enough for the low switch.
It should list the temps on the side of the switch.

[Pneuma]

Well sorry, no pictures I forgot the camera. But I tested the klixon and it terminated the defrost. Now when I popped the top the insulation sandwiched between the stainless steel walls on that side where the leaving air hits it was a little wet. It hads always seemed like vapor condensing on that wall. So has anyoen seen that? where the insulation gets wet and then is just a cold surface that collects water vapor during defrost? How do you fix it? let it dry our a few days? The insulation above the coil, that keeps air from bypassing the coil was also in bad shape so I tightened that up.

[VTP99]

Most of those top mount evaporator covers I've come across have been separated from guys opening them when their frozen in place. Separates foam in place from lower metal skin. Stupid design.

[FarleyRedfield]

Well sorry, no pictures I forgot the camera. But I tested the klixon and it terminated the defrost. Now when I popped the top the insulation sandwiched between the stainless steel walls on that side where the leaving air hits it was a little wet. It hads always seemed like vapor condensing on that wall. So has anyoen seen that? where the insulation gets wet and then is just a cold surface that collects water vapor during defrost? How do you fix it? let it dry our a few days? The insulation above the coil, that keeps air from bypassing the coil was also in bad shape so I tightened that up.

If that insulation is foam it has to be dry at least on the surface of the foam. Vapco makes a no drip spray, white in color. Spray paint the inside of the metal and foam with this. add some poly-calk (not silicone but it would work as 2nd best - then duct tape the metal back down.

This puts your vapor barrier back in place spraying with the no drip paint, and resealed the metal to the insulation. If you use aluminum tape you should be able to leave it in place. other wise you'd have to return and remove the tape.

But this is how Id fix it. there are far better geniuses in here than I am. Heck I cant even spell genius.

[itsiceman]

No the ice is clear it forms on the inside of the evaporator box on the sideof the box that air leaving the coil would hit it, up near where the top snaps on. Then it sort of runs down and forms like an icicle drip and eventually a smaller icicle forms as the water tries to drip out the hole around the fan and keeps the fan from spinning. There is even a little ice puddle inside that air diffuser, the deal with the round holes in your picture.

I got a three wire klixon on will call, I just didn't have time to get to it today. I will take some pics when I go over there in any case.Pneuma 4S&G's
Are the two air baffles missing that slope into the drain pan on either side of the evap fan as you look from the top ?

[itsiceman]

These ones