Tru Air icing up in heat mode

FDchief · 01-27-2011, 11:37 AM

I am in a Northern CA valley town which is experiencing thick fog. Temperature is 40 degrees. I have ice a third of the way up the condenser fins. I had the interior T-stat set at 72. It ran fine all night this way, but this is the first time in 7 years I have noticed the ice. I shut down the unit, and will use the furnace when encountering high humidity conditions.

Last year in FL, the A/C worked fine in the high humidity, so I am guessing it is a cold weather thing.

I cleaned both interior and exterior condensers and believe I have good air flow.

My question to the group is; do we have defrosters on our condensers like home units do? I am guessing not. Does anyone else experience icing problems in cold temps and high humidity?

Finhawk · 01-27-2011, 08:57 PM

I have found that under those conditions, ice will form. So my solution is start the furnace before it happens and stay warm.

autofish · 01-27-2011, 10:53 PM

FD...I have had this happen in Reno seems to be normal just turn unit off and let ice melt off then use furnace. Our units do not have deicers like home heat pumps do so they ice up under some conditions.

FDchief · 01-28-2011, 09:34 AM

Thanks for the replies. Even when it was iced up it was still blowing warm air so I am confident that this wasn't a low refrigerant issue. I will just take a peek during these conditions and at the first sign of icing, I will switch to furnace.

a k · 01-28-2011, 10:01 AM

Flip it on AC for about 5 minutes and it will defrost and then start over.

FDchief · 01-29-2011, 08:25 AM

Quote:

Originally Posted by a k

Flip it on AC for about 5 minutes and it will defrost and then start over.

A good suggestion, I will try this next time.

DancinCampers · 01-29-2011, 12:50 PM

I would let it run, it should shut down if the outdoor coil gets to cold.

The outside coil, along with the indoor coil, have separate circuits for each compressor. Your icing on the bottom half is from compressor #1.

These basement units do not have defrost capability, other than ambient air.

Finhawk · 01-29-2011, 01:20 PM

Quote:

Originally Posted by a k

Flip it on AC for about 5 minutes and it will defrost and then start over.

I'm curious! How does the AC come on when the temp in the coach is low already? You must have a different system in your coach

KIX · 01-30-2011, 07:58 PM

Quote:

Originally Posted by Finhawk

I'm curious! How does the AC come on when the temp in the coach is low already? You must have a different system in your coach

Just set the set temp lower than the room temp. If the eat pump is working, even if partially frosted, it should be warmer inside than the outdoor temp.

Finhawk · 01-30-2011, 10:13 PM

Ok, I'll take your word for it. I won't have a chance to check it out for a while. It doesn't get cold or damp enough in Vegas to have the frost problem. By the time I get back home to Western Washington, it will be too warm to frost up. Guess I'll never know!

KIX · 01-30-2011, 10:16 PM

Quote:

Originally Posted by Finhawk

Guess I'll never know!

There's always next year.

Finhawk · 01-30-2011, 10:22 PM

Naw, KIX, no more cold weather for me. Had enough in my day. Being a Snow Bird is great!

Finhawk · 02-02-2011, 10:15 AM

It was down to 26 in Vegas last nite and no icing. One of the advantages of getting out of cold, damp weather

FDchief · 02-02-2011, 12:11 PM

Quote:

Originally Posted by Finhawk

It was down to 26 in Vegas last nite and no icing. One of the advantages of getting out of cold, damp weather

Cold and dry here too at Lake Tahoe, CA. I believe that the magic numbers are damp with temperatures just above freezing up to around 40 degrees. I can't wait to be a snowbird starting spring of 2012!

mickey53usa · 02-08-2011, 02:17 PM

I noticed this same icing on mine last weekend. The top 1/3 of the condenser had ice on it. Outside temp was between 32 & 34. Snowing, relatively high humidity. Figured that it was just outside the range of operating temperatures for the heat pump. Good suggestion to turn the A/C side on for a few minutes. Don't think the DW would have liked it.

zippo · 02-08-2011, 06:47 PM

Where are you looking to see this ice build up?? I never see any ice, but I do see water steady dripping out of the unit, but none dripping from the black nipple as it does when cooling.

mickey53usa · 02-09-2011, 08:51 AM

On mine, the condenser is on the right (passenger) rear of the motorhome - a basement unit. You can see the icing on the condenser there.

zippo · 02-09-2011, 03:06 PM

When your unit ices up, at some point does it shut down?? If so and the thermostat is left on electric heat, does your LP furnace automatically come on to provide heat??

mickey53usa · 02-09-2011, 03:15 PM

I only have had the heat pump portion shut down once. It was about 25 degrees out and I turned on the heat pump (inside coach was 35). The heat pump came on for just a couple minutes then went off. The propane furnace did come on and warm the coach. Depending on the outside temperature, I have had both the heat pump and the propane on at the same time. Thermostat was set to "electric heat."

zippo · 02-09-2011, 04:40 PM

Thanks for the info. Mine at times will put out good heat on electric in the mid 20's, but several times I have had it quit in the night and the LP furnace did not take over (darn cold waking up to that). I've talked to Coleman and Winnebago about it and I never can get a direct answer if it's suppose to switch to LP. After I read this post about it icing up I got to wondering if mine might be icing up causing it to stop running. But I have never seen ice on mine, but I do see a lot of water dripping out the bottom of the unit like it could be ice melting off. It would be great if I could only find out if the LP is suppose to take over when the heat pump gives up and the inside temperature drops below the set. When as I say mine quits and after I notice it's gettting cool inside and need heat I can switch the switch from electric heat to off and back to electric heat and the heat pump will run fine again.