OT: heat pump freezing up! any heating specialist?

[bmwguy]

I need a AC/Heat specialist advice immediately!
Its COLD in here!

I've got a layer of ice surrounding the heat pump unit on the outside. We just recently had a snow storm 6" of snow but now there is a layer of thick ice(I'm talking more than 1/2") where the vent is and I think the unit is starving for air. This has never happend before. The unit has been blowing heat/air consistantly throughout the house and I noticed it sounds a little different too.

I've turned off the unit fearing that it would do further damage, what else can I do? I've used a heat gun to try to melt the ice but it is tedious.

I will be contacting a heating specialist soon, but I wanted to make sure if there is anything I can do.

Brrrrr!
TIA!

[Skip]

My neighbors heat pump is covered with frost/ice every heating season. Last Spring he replaced it and the new one does the same thing. You can hear the exaust fan scraping the ice and sending small bits of ice into the air. He doesn't appear to be concerned about it and he is a home improvement contractor.

http://album.gunsnet.net/data/skip/40_p6440.jpg

[RPG]

Hope this helps. Your starving for air obsevation has logic. "Cold" winter air still contains some heat. That must be able to transfer through heat exchange surfaces to get in your house. Clean the snow/ice from those surfaces and they'll be able to work. Plywood, cardboard, some kind of baffle might help to prevent blockage. Ambient air must still be able to get in. The discharge air is "colder" than air drawn in. Water's change of state from liquid to solid uses tons of energy, magnatudes more than just warmer or cooler in the same form. Refrigerant "change of state" in the heat pump is what normally heats your house. The compressor squeezes the refrigerant and concentrates the heat so it can transfer through heat exchange surface into your house. Heat exchange outside and heat exchange inside. Some heat pumps have electric de-icer/preheater functions. Yours may have malfunctioned or this may have been just too much snow and ice. Again, hope this helps, good luck. Got a manual for the unit?

[Boogieman]

Try hot water. A heat pump is just A/C in reverse...it needs air flow.

[Vladimir Berkov]

It seems to me that a heat pump is an awefully inefficient way to heat a house, and that it would be less efficient the colder it gets.

[Noah Zark]

Heat pumps are very efficient in the proper climate, but as it gets colder there is less and less heat in the air. HPs that use ground water are extremely efficient, but you have to drill a couple wells and that adds cost.

An iced up evaporator (the outside coil in the winter, and the inside coil in the summer with a HP system) can also be a function of a low refrigerent charge that forces the unit to work longer between shutdowns to satisfy the thermostat.

IF you can remove the ice that is clogging the fins, it will function better, but DO NOT use sharp tools or a hammer lest you puncture the coil. Constructing a plywood "doghouse" around the outside coil might help to contain the heat from the compressor and the fan motor which might help melt the ice. A couple of 100W bulbs carefully placed inside the doghouse away from combustables might also help to raise the temp and help melt the ice. Once the doghouse is built, the heat form the compressor, fan, and light bulbs might start building up and melting the ice.

Try closing off registers and doors to unused rooms and minimise the area to be heated. Also, if you or yours does holiday baking, now would be a good time to do so as the kitchen oven heat is almost all transferred to the inside of the dwelling. I'm serious, bake all those holiday cookies today.

I would have a tech check the charge as soon as possible. He'll do this by looking at the high side and low side pressures, which will be a bit out of whack anyway since the evaporator is not transferring much heat. That could be why it sounds differently to you.



Good luck,

Noah

[bmwguy]

Thanks for the reply thus far-

The tech/friend just stopped by.

There is enough freon in the unit. However, he did find that the Defrost timer is busted. So the search goes on.

I have a early eighties unit that's kinda obsolete, and he said it'll be hard to find it.

Anyone have any leads as to where I can possibly find this part?
the unit is a:

GE Weathertron, Model number: BWB930A100A0,
Again part needed is a Defrost Timer.

TIA!

[AKMac]

Heat pump? I've never heard, or seen one of them before? Don't people back east use a furness? That thing in the picture looks sort of like a central air unit. I guess since we usually get a couple ft of snow, a "heat pump" wouldn't work very well when it's buried in snow. Man, that heat pump thing is weird.

[Noah Zark]

That GE Weathertron is only a temperature sensing switch. It probably has a capillary sensing bulb that looks like a copper wire but it it really a hollow tube filled with a thermo-expanding liquid like a thermometer. In this application, the liquid contracts with reducing temperature, and the force of an opposing spring closes electrical contacts to bring on your resistance heating defrost coils. If that copper bulb gets damaged and leaks, no more function.

You wouldn't necessarily need the exact same temperature sensing switch. The plate on the GE switch should have volts, amps, watts, etc. and maybe even the tempeature range, and you can match another maker's swtich to it. The GE switch probably is wired to the coil on a relay contactor that closes and turns on the defrost heater coils. I doubt of the GE switch is directly wired to the coils, but it may well be. The GE switch probably has a small screw to adjust the temperature at which the switch contacts open or close, and the replacement will probably have a similar adjustment knob or screw. Any of the electrical controls manufacturers (Honeywell, Allen-Bradley, Watlow, etc.) will make an adjustable low-temp sensing switch that will be suitable. IF your tech is accustomed to a different brand of heat pump and can't cross-reference the switch, a local electrical supply house should be able to take the GE unit and match it up for you and the tech should be able to retrofit it to the outside coil.

Cookies done yet? Send two dozen Toll House Chocolate Chip to my attention in exchange for the advice. :D

Noah

[sfc ret]

something is definetly wrong with it I have a heat pump and never had ice built up around it like that........ I went to all electric 7 years ago, and bought a heat pump and electric furance, electric water heater, and got a 700 dollar rebate as well as getting wholesale rate for electicity from the ILLUMINATING CO. they make their own power. I spend less per month then folks spend on gas up here on a monthly basis, and when you talk about efficency a electric furance/heat pump is 100%... all the heat goes in the house none up the chimney to warm the birds. that roost around there for warmth.

and living in cleveland there is no snow build up around it, and it snows pretty good up here, house is nice and cozy in the winter and nice and cool in the summer. :)

right know it's like 25 degree outside and there is enough warm air outside that the heat pump is working like a champ....when it goes down to the lower teens, and single digit is when the furnace kicks on.

I used a average of about 1500 KWH a month and pay about 110 bucks a month (latest bill)....my brother in law has a gas furance and his average monthly gas bill durning the winter is somewhere in the $350 range....OUCH

I don't know the principle of the thing but I do know the fan every now and again is suppose to reverse airflow to keep ice from forming on the coils, did you check the fuses to see if any of them are blown? ....best advice get somebody to check it out...you don't want that compressor to get fucked up....that's the heart of the heat pump and cost much bucks.

as for what to do in the meantime....isn't there a switch on your thermostat that says EMERG HEAT, or EM heat(emergency heat)? I don't know about virgina..but here in northern ohio if you have a heat pump, you have to have a back up system, that being the furnace, you can't have just a heat pump as your only source of heat...just in case something goes wrong with the heat pump, you have another means of heat....if you don't have a furance...make a lot of hot coffee, and hot coco and call a heating company on their emergency number.

[DaveN]

Just have your serial # and model number and go to the GE website..I ordered parts for my 20 year old GE fridge and dishwasher there..a bit pricey though..they respond to your technical questions too the next day

[jamie930]

To fix it in the mean time just get a piece of cardboard to block the air coming out of the outdoor fan and turn the thermostat to the ac setting and turn it down to start the ac. Just run the ac with the outdoor fan blocked off with cardboard. The ice will melt right off. Most heat pumps switch over to ac for a defrost with the outdoor fan off. You are just doing it manually.

[GrinningGun]

Or just turn the water hose on, and spray it for a few hours. Liquid water is always hotter than frozen water. Just prop the hose so it runs on the unit, and it will melt the ice away. Definitely needs some fixing though.

[sodblaster]

...turn on the "alt" or "EM"on your thermotat if you have a setting like that. This will change you over to the heat strips, and you'll be using elec. resistance. Your unit could have a bad expansion valve or a bad defroster. This problem is common with York and GE. What's yours? sfc was correct with the 100% efficiency rating of elec. resistance only. The "LUKE" pump (not heat, because it's only lukewarm at best) :rolleyes: has what's called coefficeint of performance (COP) Most HP's have a COP of 3:1 with ground/water source HPs go over 5:1. That's to say that the system will give you 3 units of heat for every unit of elec. that it uses. Folks shouldn't confuse "energy efficiency" with economical. There are MANY other factors involved with sfc ret's lower utility bill than just a heat pump. A house is an inannimate object that is incapable of fooling with a thermostat, turning on lights,lingering in the shower, etc. It is the "non-mechanized" systems within a household that regulates the bills, (the human element). His thriftyness and energy awareness, :cool: are probably more instrumental.

[bmwguy]

Thanks all!

I am able to locate the exact part, it is now sold under Trane.

NOah Zark, Absolutely the cookies are ready!

On top of chocolate chip, I have Oatmeal as well as white chocolate chunk with macadamia nut, my favorite.

:D

[bulgarianak]

I live in VA too and most people with heat pumps have that as their only heat source, unless they got a fireplace. Keep the outside unit ice free and make sure it has room around it for air to get up and around the unit. The emergency heat should turn on when it gets too cold for the heat pump to work well enough. The heat pump has the heating strips or coils or whatever and that should help to warm you up.