Weatherton 1000 3 ton HP problem

[yahtzein]

Been having a problem the tech can't find or fix. The hp will work for around 45 mins (+12-15) air coming out of the nearest vent to air temp and will stay for an extended period. When you short the test to frc-dft while +12-15 coming out of the hp itll start up the defrost, but when the hp is putting out room temp air it will not start the defrost, it'll stop and sit until you turn the thermostat off and back. Ideas or a good tech in the dc area (martinsburg, wv)?

[yahtzein]

The thermostat I set to heat (66 all day long) and have turned off the aux to test it sometimes (programmable one) The fan is set to auto. The heat pump fan will run outside, maybe the compressor shuts off ?? though after the 45 min, but the heat pump will put out heat and then room temp for over an hour and will put out heat again after a hour plus of room temp air and repeat itself. So the compressor must shut off or like you said it would turn to a block of ice, but could the compressor be off and the fan on the unit (outside)?. Thermostat hasn't been changed in years and didn't have any problem like this last winter

Its a problem though since if left alone our heating bill went up $200 since the heat pump doesn't work correctly and it uses the heating strips all the time instead.

[yahtzein]

he used gages to check the charge on the unit and that's about it besides forcing the defrost.

I thought it was an overload or defrost board problem, but he didn't seem to think so. In decemeber when I knew we had the problem it would run for 45 minutes about, then after he came somehow it was around 3 hours. Now its back to 45 minutes.

If I force the defrost itll keep running for about another 45 minutes, but then will put out room temp air again.

[yahtzein]

The tech I had check it out said if it went to overload it wouldn't start up again, it would have to get turned off and on again. If it went into overload would it not start the forced defrost and would the fan still run? Plus the unit puts out heat again when you leave the thermostat at heat for a hour or two.

[yahtzein]

Watched it closely yesterday and it ran for 3 hours, did a defrost cycle, ran 45 min did a refrost cycle, ran 45, then room temp air for 45, ran again. First time in a long time its actually done defrost cycles on its own. Normally itll only do it once a couple days

The only thing I don't understand would be if the compressor shuts off in overload why would it be happening in 45 or 3 hours intervals. And if the compressor would be shutting off I assume that the compressor is on the way out?

Guess I'll be getting another tech to come out, but don't see how I'll be able to create the problem for them for sure since they'll not be able to fix it unless its showing its ugly head when they're here.

Also, the compressor doesn't run when the unit puts out room temp air. I also checked be meter and it used about 1 kw in 45 minutes while off. Its uses 4kw plus other running equipment in the house while its running so 4.5-5kw per hour is normal while its working. Could the defrost board be going bad so its stopping the compressor, but then not doing the cycle and staying off 45 min before turning back on? Or is it more likely for the txv value, or a check value going bad?

[nomadpeo]

there are a number of possibilities. the fact that it doesn't keep up on a mild day suggests that the performance problem may be related to a freon level or possibly a starting problem. when the compressor overheats, there is an underlying cause. compressor amps, pumping capability, metering device feed, defrost function, capacitors, contactor, freon level, superheat, sub-cooling, od stat all need to be properly tested by a qualified technician. while an intermitent problem can be evasive, it sounds like you may have a solid problem that can be detected with the right tests. you may need to get a second opinion.

[yahtzein]

I found the defrost senor plug into the defrost board was loose and thinking it may actually be the problem. If the units timer is at 45 minutes and it goes to check the defrost sensor, but its loose (basically unplugged) would this happen? And would the unit run with the defrost even unplugged?

After I unplugged and plugged it back in the unit operated more often than usual without the 45 minutes periods with the compressor off